• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Preface
 Part I: Organic kingdoms
 Part II: Florida truck and garden...
 Part III: Miscellaneous






Group Title: New series
Title: Plant diseases and pests and their treatment
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00003034/00001
 Material Information
Title: Plant diseases and pests and their treatment
Alternate Title: New series bulletin - Florida State Department of Agriculture ; 3
Physical Description: 376 p. : ill. ; 23 cm.
Language: English
Creator: Brooks, T. J ( Thomas Joseph ), b. 1870
Florida -- Dept. of Agriculture
Publisher: State of Florida
Place of Publication: Tallahassee, Fla.
Manufacturer: Rose Printing Company
Publication Date: 1947
Copyright Date: 1947
 Subjects
Subject: Phytopathogenic microorganisms -- Control   ( lcsh )
Agricultural pests -- Control   ( lcsh )
Genre: governmental publication   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: compiled by T.J. Brooks.
General Note: "Florida bulletin of the Department of Agriculture revised March, 1947."-- T.p.
General Note: Includes index.
 Record Information
Bibliographic ID: UF00003034
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAA3475
ltuf - AKD9382
oclc - 30119284
alephbibnum - 001962705

Table of Contents
    Front Cover
        Page 1
    Title Page
        Page 2
        Page 3
    Preface
        Page 4
    Part I: Organic kingdoms
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
    Part II: Florida truck and garden insects
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
        Page 111
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
        Page 122
        Page 123
        Page 124
        Page 125
        Page 126
        Page 127
        Page 128
        Page 129
        Page 130
        Page 131
        Page 132
        Page 133
        Page 134
        Page 135
        Page 136
        Page 137
        Page 138
        Page 139
        Page 140
        Page 141
        Page 142
        Page 143
        Page 144
        Page 145
        Page 146
        Page 147
        Page 148
        Page 149
        Page 150
        Page 151
        Page 152
        Page 153
        Page 154
        Page 155
        Page 156
        Page 157
        Page 158
        Page 159
        Page 160
        Page 161
        Page 162
        Page 163
        Page 164
        Page 165
        Page 166
        Page 167
        Page 168
        Page 169
        Page 170
        Page 171
        Page 172
        Page 173
        Page 174
        Page 175
        Page 176
        Page 177
        Page 178
        Page 179
        Page 180
        Page 181
        Page 182
        Page 183
        Page 184
        Page 185
        Page 186
        Page 187
        Page 188
    Part III: Miscellaneous
        Page 189
        Page 190
        Page 191
        Page 192
        Page 193
        Page 194
        Page 195
        Page 196
        Page 197
        Page 198
        Page 199
        Page 200
        Page 201
        Page 202
        Page 203
        Page 204
        Page 205
        Page 206
        Page 207
        Page 208
        Page 209
        Page 210
        Page 211
        Page 212
        Page 213
        Page 214
        Page 215
        Page 216
        Page 217
        Page 218
        Page 219
        Page 220
        Page 221
        Page 222
        Page 223
        Page 224
        Page 225
        Page 226
        Page 227
        Page 228
        Page 229
        Page 230
        Page 231
        Page 232
        Page 233
        Page 234
        Page 235
        Page 236
        Page 237
        Page 238
        Page 239
        Page 240
        Page 241
        Page 242
        Page 243
        Page 244
        Page 245
        Page 246
        Page 247
        Page 248
        Page 249
        Page 250
        Page 251
        Page 252
        Page 253
        Page 254
        Page 255
        Page 256
        Page 257
        Page 258
        Page 259
        Page 260
        Page 261
        Page 262
        Page 263
        Page 264
        Page 265
        Page 266
        Page 267
        Page 268
        Page 269
        Page 270
        Page 271
        Page 272
        Page 273
        Page 274
        Page 275
        Page 276
        Page 277
        Page 278
        Page 279
        Page 280
Full Text


Number 3 ''


Plant Diseases and Pests

and


Their Treatment


FLORIDA BULLETIN OF THE DEPARTMENT
OF AGRICULTURE
REVISED MARCH, 1947



Compiled by
T. J. BROOKS
Assistant Commissioner of Agriculture




CONTENTS


Part I-Organic Kingdoms: The Struggle Between the
Higher and Lower Orders of Life; Life Kingdoms Out-
lined; Classes of Parasites; Methods of Transmission of
Plant Diseases; Forms of Bacteria; Pathogenic Bacteria.
Part II-Florida Truck and Garden Insects.
Part IIIn-Miscellaneous.



NATHAN MAYO
Commissioner of Agriculture


ROSE PRINTING COMPANY


New S:eriies





.Ne\(.w Sc"ries


Plant Diseases and Pests

and


Their Treatment


FLORIDA BULLETIN OF THE DEPARTMENT
OF AGRICULTURE
REVISED MARCH. 1947



Compiled by
T. J. BROOKS
Assistant Commissioner of Agriculture



CONTENTS


Part I-Organic Kingdoms: The Struggle Between the
Higher and Lcwer Orders of Life: Life Kingdoms Out-
lined; Classes of Parasites; Methods of Transmission of
Plant Diseases: Forms of Bacteria; Pathogenic Bacteria.
Part II-Florida Truck and Garden Insects.
Part III-Miscellaneous.



NATHAN MAYO
Commissioner of Agriculture


Number :1


































ALL ILLUSTRATIONS IN THIS BULLETIN
ARE BY COURTESY OF
THE FLORIDA AGRICULTURAL EXPERIMENT STATION







PREFACE


MAN AGAINST INSECTS

Man lihas iany enemies in the world. During ii he past
it seems as though all the elements of nature have combined
against him-drouths, floods, earthquakes, dust-storms and
tornadoes VWe h av read so Iullllc of late about I Ihcse ldextrite-
tive forces and the devastation they have left behind, that we
are apt to forget about other smaller enemies who are no less
deadly to our welfare-insects.
These creatures. so small that usually we do not even notice
them. work their insidious war against man in a thousand ways.
They carry disease. They ruin his crops. and attack the animals
that labor for him. They breakfast on his books. lunch on
his clothes, and dine on his furniture and food. Their individual
work is minute, but often they travel in vast armies-like the
great swarms of locusts-and leave a blanket of barren waste
behind where there were waving fields of grain before.
The chinchh bugs" often spread through the grain country
of the prairie slates. They travel, like an epidemic. in search
of corn and wheat for food, threatening the grain supply from
which our daily bread is made.
Well may man gird himself against the insect world. Fire
and earthquakes and termpests frighten us with their ominous
fury but many people believe that if mankind is ever destroyed
it will not be by these spectacular elements. nut by hordes of
tiny I hius.


T. .1. BROOKS.






Plant Diseases and Pests

Part One
CHAPTER I
BY T. J. BROOKS
Assistant Commissioner of Agriculture
The Struggle Between the Higher and Lower Orders of Life
Maln is destined to struigile for his existence iand tihe attain-
ment of his desires. It is by struggle that he advances. The
IImore complex the civilization thlie more strelluous the struggle.
Only the primitive harbariani has no complex problems to worry
him. The absence of difficult problems indicates a primitive
society. The capacity of the human race to support themselves
in great iiinuilers' i;n ii givenl territory is dependent uilX)ll a
coinllex social conipa|ct and efficiency of efforts. The wider
the circle of man's activities the stronger the conflict between
mankind and nature.
IThe striliggle between m11a an d the i icroscopic organlismlls
of tih living world has lbeconmi intensified many fold during
the last century. The intensificalion has been brought about
by the spread of parasites aind the diseases which they produce
on the animal and vegetable kingdoms. This spread has been
accentuated by the universal exchange of conimodities and the
migration of people from cliime to clime.
But for some friendly help allomlatically furnished by certain
of t11e feathered tribe and other consumers of worms and
insects lthe struggle would have been vastly intensified. lie
has not always appreciated tliese helpers in the struggle for
existence.
It is not much trouble for nman to rid the community of
wild ganme of the larger kinds. that are a menace to him or
his crops and domestic animals. but when it comes to dealing
with the microscopic living world the struggle is shifted to
an entirely different field. Although he has among these some




DEPARTMENT OF AGRICULTURE


which contribute to his welfare there is enough of the injurious
kind to render it necessary for him to be of grave concern.
In the outlines which have preceded the attempt has been
made to place before the reader a comparative analysis or
classification of living things, so as to make it easy to see the
relationship of living creatures to man's welfare. Knowing
this, it will be easier to protect plants and animals from the
inroads of their enemies. The pursuit of this task is more
interesting as we understand the characteristics and life habits
of the underworld which we must combat.
There are 475,000* species of insects already classified, and
several times as many not classified. A large per cent of these
are parasitic-pestiferous as to plants or animals, or both.
The distribution of these enemies of life is so nearly universal
and their operation is so continuous and destructive that they
constitute man's greatest economic and physiological menace.
Millions of dollars must be spent annually to combat the enemies
of vegetation and other millions to combat the enemies of
animals and of man.
Man has enough to enlist all his fighting energies if he
keeps back the armies of untold millions and billions which
are continually attacking him personally and the sources of
his means of a livelihood. Only by constant vigilance and the
help of science and the art of employing efficiently the most
destructive agencies to the myriads of creatures which are a
menace to the vegetable and animal kingdoms which minister
to the welfare of mankind can the race survive in the struggle
for existence.
Diseases not caused by pathogenic germs are called degenera-
tive diseases-some of which are caused by improper food.

LIFE KINGDOMS
The two great life kingdoms are the vegetable and the
animal. There is a point where the two kingdoms so nearly
blend that the line of demarcation eludes the scientist.
*Note. Authority for these flures Is Webster's unabridged dictionary





PLIANT I)ISFL\SES AN!) lEPST-`


Zoology being that branch of biology that treats of animal
life, has various schemes of classification adopted by naturalists.
The following classification is standard and will help us to
locate our subject in the general scheme of biological studies.
(Many smaller divisions are omitted.)
Classification of the Animal Kingdom
Phylum I; Prolozou (One called animals)
Class 1. Sarcodina
('lass 2. Mastigophora
(lass 3:, Sporozoa
(lass 4. Infusoria

'hylmn111 11 : I'orifera (Sponges
'hylhin III: ("clenterata (Forms possessing a coelenteron)
lhyluIm IV:; tenophora ("See Walnuts")
'liylum V; Platyhelminllhs (Flatworms)
'Phylum VI: Nrmatlhelmintlh .s (ouidlwormis)
Phylun VII; Annelida (Segmented worms)
Phylum VII I; Arthronlw)d (Joint-footed animals; lobster. crabs.
centipedes, scorpions. spiders mites. insects)
Phylum IX : Mollit.cal (Snails. clams. oysters. octopods.
nautili)
l1hy11um XN: Echiude'rmit (Starfish. sea urchins. sea lilies,
etc.
Phylum XI : C('hrdai
Sub-phylum I: Enteropneusta
Sub-phylum 2: Tunicata
Sub-phylum :3: (ephalochorda
Siub-phyluni 4: V'ertebrata

Class 1 ('yclhstomata (lnampreys and lags)
('lass 2 Elasmnobranchii (Sharks. Itays. etc.i
Class :3 Pisces l'ish)
Class 4 Amnihiia (Frogs. Toads. Salamandlers)
('lass .5 Reptilia (Turtles. Liizards. Snakkes. ('roodmlilis)
(lass 6 Aves (lIirds)
(lass 7 M.amnmalia ( (Hairy Quadrupeds, Whales. Seals,
Bats, .Monkeys. and MIHan)





DEPARTMENT OF AGRICULTURE


*Some Specialised Fields of Biological Study Are as Follows:

1. Mammalogy treats of mammals, a class of vertebrates
whose females have milk-secreting mammary glands to
nourish their young, embracing all warm-bodied quadru-
peds, also bats, seals, cetaceans and sirenians.
2. Ornithology, of birds;
3. Herpetology, of reptiles;
4. Ichthyology, of fishes and lower aquatic vertebrates;
5. Ascidiology, of the tunicata-a division of metazoans;
6. Echinology, of the echinodermata-a division variously.
ranked;
7. Conchology. of the molusca;
8. ENTOMOLOGY. of the INSECTA;
9. ARACHNOLOGY, of the AR.ACHNIDA-spiders. scor-
pions, etc.;
10. .'rustaceology, of the crustacea lobsters, crawfish,
shrimp, pranks, barnacles, sow bugs, etc.:
11. IIELMINTHOLOGY, of the worms;
12. Zoophytology, of the coelentera-invertebrates as coral,
or hydroid, the sea anemones, jelly fish, etc.
13. Paleontology, of the fossil remains of plants and animals.
14. Parasitology, of parasites.

**Some Special Fields of Study of the Vegetable Kingdom

Botany being the science of plants is somewhat older than
zoology, but its nomenclature was long the subject of con-
troversy. The International Botanical Congress of 1905
(which met in Vienna) adopted certain rules which have done

*Those organisms that destroy, and subjects relating thereto, are capitalized in
the following outline. We are concerned about those that are useful but for the
present discussion we are more concerned about the destructive creatures of the
living world.
There are disorders of plants and animals caused by numerous things other
than parasites. Among the diseases of plants which are not caused by organisms
may be mentioned those caused by injurious sprays, poisonous gases. malnutrition,
dieback due to lack of drainage or too much ammonia, etc. Injuries from frost.
heat. flood. drouth. depredations by insects and higher animals are not really diseases.
**Topicl 1-5 apply to the animal as well as the plant kingdom.





PLANT DISEASES AND lPETS


much to briiig order out of confusion. The branches of
botany of most eoncelrn here are:

1. Morphology. relating to external form:
2. Histology, relating to structure of tissues:
:1. Cytology, relating to the cell:
4. Embryology, deals with the development of the egg-.ell;
.5. PIhysiology. with the functtimos anil vital actions of or-
gaiis:
6. PHIIYTOPATIlOIl,()(Y. with PLANT 1)ISEASES:
7. Ecology. with environment influences;
S. IPllytogeographly. with plant distribution:
9. Taxo0nomy. with the classification of plants:
10). I'alcohotanly. of fossil plaits:
11. ECONOMI(C IOTANY.- including:

(a) A.gricultiire (d) PI'arniamc)gi(os
(I) Forestry e Floriculture
(eI HlortiIulture and coLnlate sll).jiccts.

Animal life is defined as "Sentient organism.s. having
organs ,of sense: life wh.lic feed oil other orgaianisls. Aii-
lmal life is usually to he distinguished by1. its ability to take
food into a (lig.estive tract or cavity. mall by) the power of
voluIntary molltiol."

CERTAIN CHARACTERISTICS

A. \ivilpora: lThose which are hIrn and stckle their young
a Mala
bi All warm-blooded (quaidrupeds
Be ats. seals, cetaceans and sirenian.s

H. Oviporl : IThose that hatch from eggs and do not suclkle
a Fish r Insects
h Fowls (I leptiles-exceptiolls
('. Spores
a Protoz.oan.s b Bacteria
The following outlines are given to sIhow the similarity of
the classification of the animal and plant kingdoms.






DEPARTMENT OF AGRICULTURE


The comparative relationships of the various divisions of
the animal kingdom may be shown as follows:
A Kingdom
1 Phylum
2 Sub-Phyluam
3 Class
4 Sub-Class
I Order
A. Phyla: 6 Sub-Order
7 Family
1 Protozoa 8 Sub-amily
2 Porifera o10 pecte
3 Coelenterata 1 train
4 Vermes
5 Mollusca
6 Echinodermata
7 Vertebrata
8 Arthropoda

Vegetable life is defined as "living organisms not possessed
of animal life."

The comparative relationship of the various divisions of the
plant kingdom may be divided as follows:.
A Kingdom
1 Phylum
2 Sub-Phylum
3 Class
4 Sub-Cass
5 Order
0 Sub-Order
7 Family
8 Bub-Family
9 Oenus
10 Speci
11 Breed
1I Strain
2 Phyla:
3 Cryptogamla: owerless--propagating by spores
1 Myzophyta: slime molds-not all of them
2 Thallophyta: algae, fungi and lichens
3 Bryophyta: mosses and liveworts
4 Pterodophyta: ferns and their allies
5 Schezophyt: fusion plants. including bacteria
4 Phanerogamla: flowering-having stamens and plstils
1 Angtsperms
1 Dicotyledons
2 Monoctyledons
2 8permatophytas
3 Oymnosperms

CLASSES OF PARASITES
The Diseases They Produce in Plants, and Remedies
I. Animal Parasites: Any form of animal life that lives in
or on and at the expense of another form.





IPIUANT DISEASES ANDI PESTS


A. Insects: Six-legged anthropods; 475,000 species
have heen named and five times as many unnamed.


(1) Kinds
(a) Chewing
Curculio
Codling moth
Canker worm
Fall web worm
Tent Caterpillar
Pear slug


Larva of moths and butter
Beetles and their grubs
Grasshoppers
Crickets
Saw flies and their larva


Sprays for Chewing Insects


1. Paris green
2. Arsenate of lead
3. Arsenate of soda
1. Arscnate of line

(h) Sucking
San .lose scale
Oyster shell scale
Plant lice


5. Scheele's green
6. London purple
7. White arsenate
8. Hellebore


4. Leaf hoppers
5. Pear Psylla


Sprays for Sucking Insects


1. Lime sulphur
o('oIIcv it rat es
2. Self-hoiled lime-
sulphur
3. Fish-oil soap wash
4. Kerosene emulsion
5. (rude petroleum
emulsion. distilled
emulsion


Nicotine solution
Pyrethrum
Caustic potash
Carbolic acid emulsion
Sulphur spray
Resin wash


Fumigants
Effective against all insects when feasible to use them:
1. llydrocyanie acid 2. Carbon disulphide
Igs 3. Sulphur dioxide

The female mosquito is carnivorous, while the male is herbiv-
orous--clewing plants and sucking animals. It is a menace
only to the latter.





12 DEPARTMENT OF AGRICULTURE

B1 Vegetable Parasites: Organisms not possessed of animal
life.
a2 Fungi: Thallophytic plants destitute of chlorophyl
aS Obligatory parasites, with power to exist under
but one condition
b3 Faculative parasites, having power to accommo-
date themselves to different conditions
c3 Obligate saphrophytes, living on dead organic
matter


d3 Faculative saphrophytes,
oxygen.


living without free


Diseases They Produce in Plants
1. Brown rot of peach 6. Smut
2. Bitter rot of apple 7. Mildew
3. Rusts 8. Some "blights"
4. Scabs 9. Citrus canker
5. Moulds

Citrus canker is caused by the fungous Macrophoma
curvispora.


Sprays for Vegetable Parasites


1. Bordeaux mixture
2. Lime sulphur
3. Sulphur dust


4. Copper sulphate-lime dust
5. Corrosive sublimate


b2 Slime Molds: Not differentiated into cells, a mass of
protoplasm propagating by spores-functioning as
seed in plants.
c2 Cuscuta:
d2 Bacteria: The unicellular variety which propagates by
fisson-splitting of the organism. No universally ac-
cepted and satisfactory classification of bacteria has
been made.







Methods of Transmission of Plant Diseases

'There airte i inumbller of inftliolds by whici plant diseases
aire transmitted:

1. By soil inoculation: suchl as the Irish potato scab, the
Irish potato rhizoetonia. and tli same with Ibeais and onions,
tomato fuscopiceous wilt. and letluce drop.
2. By water infection: as the lemon brown rot of ('ali-
fornia.
3. By air infection: is the lelloonl seal, celery leaf spot,
cuciIinuber downy inildlew. tohalieo peronloaper. peach brown
rot.
4. By insect transportation: sucli ais pear fire blight,
cuunliber wilt-hacterial-llpotato niosaic. peachl brown rot.
5. By seed inoculationl as heai antliraicose. bean bacterial
blight. sugar cane red rot. watermelon alntlhracnose, encumlber
angular leaf spot.
6. By dleald wood: sulcl ais wither tip of citrus fruit. steim-
ien(d rot of citrus fruits.
7. By miscellaneous metliodls: some diseases are spread by
more thaiiii one imetlod.


Other Divisions of the Subject of Plant Diseases


As to elfect of disease on plants:
1. Killing: blights. rusts, wilts. etc.
2. Redil ing health collditions
:3. P'rolducing lmalformatioins
As to parts affected:
1. Roots
2. Stalk
3. Foliage
4. Fruit


PLAN\S'r DISEASES' AND iIFs'rs





DEPARTMENT OF AGRICULTURE


As to kind of plants attacked:
1. Forests
2. Fruit groves
3. Field crops
4. Truck crops
5. Ornamental shrubs
6. Vines

Pathology is the study of abnormal conditions; their causes,
symptoms and characteristics-including a study of physiol-
ogy and anatomy.

Therapeutics is that department of medical science that
relates to the treatment of disease and the action of remedial
agents on the organism, both in health and disease.

A physician is one versed in or practicing the art of medi-
cine or healing bodily diseases, usually by the administration
of remedies regarded as standard by the profession-such as
are in the Pharmacopoeia.

Forms of Bacteria

A bacterium is a schizomycetes. or microscopic fusion fun.
gus-a non-spore former.
Spherical bacteria-cocci.
Rod-shaped bacteria-bacilli-spore former.
Spiral bacteria-spirilla.

Pathogenic bacteria: capable of doing harm directly-a few
score of them. Two general classes: those which are strictly
parasitic and those which live free in nature. A full list of the
species and of the diseases which they produce would be too
comprehensive for present purposes even were such a list scien-
tifically established.






PLANT'I' I)ISEASES AND PES'TR


NAME OP ORGANISM TYPE OP DISEASE PRODUCED
Corynebacterium diphtherlac Diphtheria
Microbacterlum leprae Leprosy
Clostridium tetnal Lockjaw
Clostridium botullnum Pood poisoning (toxic)
Salmonella enterltldis Pood poisoning cellular,
Ebrethella typhi
Ebrethella para-typhi A Typhoid fever
Ebrethella para-typhi B
Brucella abortus Contagious abortion in cattle
Brucella melatensis Relapsing fever
Neisseria gonorrhoeac Gonorrhoea
Treponema pallldium Syphilis
Pneumococcus Itypes 1. 2. 3. 4, Pneumonia
Staphylococci several types' Colds and sore throats
Streptococcus scarletina Scarlet fever
Shigella dysenterine Dysentery (Bacillarys
Endamocba histolytica Dysentery (amoeboldi
Vibrio comma Asiatic cholera
Lactobacillus acldophllus Sours milk
Lactobacillus bulgaricus Sours milk
Bacteria initrifyings Lodge In root nodules where they izate
nitrogen.
Such diseases as smallpox, measles, mumps. yellow fever. infantile paralysis
,acute anterior poliomyelitis). "parrot fever". and many others are caused by
specific substances called Illterable cfruses, the nature of which has not been agreed
upon by authorities.

A plant pathologist is otitv versed iu diagnosing and treating
plant dlisei.ses.

It is an anomaly il the economy of nature that human life
is dependent upio01 in(ero-organismns and at the same time the
greatest enemies of tile human race are to be found among these
Illicro-orlga lliSiiis.

Some of the uses ,of lbateeria Itay be mentioned-
i[ the arts:

1. Maceration Industrie.s--Such as Linen. .lute. Ilemp.
Sponges. Leather.
2. Fermentative J(ndsties-Such as Vinegar. Lactic acid.
Butyrie acid. leacteria in Tobacco Curing.
In Natural Processes:
I.-As ZScavengers.
2.-In Food Processes.
3.-In Soil Fertility.
4.-In Silo.
5.-In1 the Dairy.
The Science of microscopic life is modern in origin-in a prac-
tical sense it is less than a hundred years old. All parasites





DEPARTMENT OF AGRICULTURE


are not microscopic, and such as are not received earlier atten-
tion. Insects, fungi, and bacteria constitute a militant army
that is the most formidable enemy of the human race. Some
of these are man's friends, and it behooves him to understand
each class, that he may cope with the problems which they
present.
That branch of biology which-includes a study of human
life reaches its highest and most complex themes in psychology
and sociology.
Morphology treats of form-the static form of life.
Physiology treats of function-the dynamic phase of life.
For the purpose of our present study we shall have to con-
fine ourselves to those branches of biology which have to do
with organisms that work an economic injury to the human
race, touching incidentally those which work a physical injury
in our treatment of bacteria.
Therefore, by process of elimination, we come to three
branches of biological study:
Entomology-the study of insect life, as it relates to plant
pathology and economic botany.
Mycology-the study of fungi, as it relates to plant pathol-
ogy and economic botany.
Bacteriology-the study of bacteria, as it relates to plant
pathology, economic botany and human pathology-pathogenic
bacteria.
The limitation of this volume will not permit a treatise on
each of these subjects. Therefore we shall devote space only
to pathogenic bacteria. The reader is concerned principally
with means and methods of destroying injurious insects, bacteria
and fungi.

PATHOGENIC BACTERIA
Destructive Organisms

(Affecting the Inman Body)
Pathogenic. disease-producing bacteria constitute a relatively
small number of species of bacteria. The harmless species are





PLANT DISEASES AND PESTS


not parasitic and cannot grow in an animal organism. There
are two general classes of bacteria which cause disease.
1. The non-pathogenic class, which live free in nature and are
not strictly speaking parasitic.
2. The true parasitic class. which live in the bodies of animals.
The most generally accepted theory of how bacteria cause
disease is that they produce in their growth a number of by-
products of decomposition and that some of these by-products
are poisonous. It has not been shown that all pathogenic germs
produce their effect that way, but it has been proven that it is
the method in a number of cases.
Other methods are tissue destruction an d mechanical blocking
of organs.
Recognizing that bacteria may produce poisons. we readily
see that it is not always necessary that they should he parasitic
in order to produce trouble.
Ptomaine poison is caused by eating putrified animal matter,
or of alkaloids produced by bacteria. An alkaloid is any nitro-
genous organic base. especially of vegetable origin. having a
powerful toxic effect on the animal economy.-as strychnine
or morphine.
It is not always the case that a specific germ produces a
definite disease, nor that each germ disease has its specific
bacterium. For instance, the inflammation of wounds. forma-
tion of pus. or the different types of blood poisoning, such as
septicaemia yaenmia. gangrene. etc.. all appear to be caused
by bacteria, and it is impossible to make out any definite
species associated with the different types of these troubles.
The organism which normally causes influenza may also cause
such diseases as conjunctivitis. mastoiditis. osteormyelitis. menin-
gitis. pneumonia, endocarditis. peritonitis. bronchitis. There
are three forms of so-called pus cocci, and these are found almost
indiscriminately with various types of inflammatory troubles.
Organisms are in the air. in the ground, in the water, on
clothing, on the skin. in the mouth and the alimentary canal.
Commonly they do no harm. but they have tile power of doing
injury if they get into wounds or susceptible membranes. Some




DEPARTMENT OF AGRICULTURE


species are universal inhabitants of the alimentary canal and
are ordinarily harmless or beneficial but'under other conditions
they invade the tissues and give serious trouble.
The following diseases are among those regarded as caused
by distinct specific bacteria: Typoid fever, whooping cough,
scarlet fever, pneumonia, syphilis.
Most pathogenic bacteria can be in some way so treated
as to suffer a diminution or complete loss of their powers of
producing a fatal disease; on the other hand conditions may
cause an increase in the virulence of a pathogenic germ.
The general course of a germ disease is divided into three
stages: (a) incubation, (b) development, (c) recovery. Dis-
ease germs enter the body through the mouth, nose, skin and
secretary ducts.
The germs of scarlet fever, tuberculosis, pneumonia, etc.,
are carried to us through the air and breathed into the cells
of the lungs, where they find lodgment and penetrate the
delicate membrances and get into the circulation. It is then
that a battle ensues between the powers of the body and the
microscopic invaders Only a few of the thousands of species
are able to combat nature's resisting power. Those that some-
times win out and produce disease we designate as pathogenic.
The human body possesses extremely remarkable protective
methods against the invasion of bacteria or other foreign sub.
stances. These defense mechanisms may be placed in three
general categories, namely: (1) Humoral antibodies--(agglu-
tinins, precipitins, lysins, opsonins and antitoxins). (2) Phag-
ocytosis-(a function of the white blood cells). (3) Comple-
ment or alexins. The last of these three may be placed with
the first as a humoral antibody, but differs from other humoral
antibodies in that it is non-specific for all types of invasion
into the blood stream, and in that it is "always present in all
normal blood.
The introduction into the blood stream of any foreign sub-
stance will encite the activity of one or more of the above
protective agencies, and thus is the struggle to overcome dis-
ease begun. Recovery of the individual follows if enough





PLANT DISEASES AND) PESTS


antibodies can be produced to successfully combat the invading
organism. On the other hand, death follows if the invading
organisms are able to overcome the above mentioned protective
agencies.
Once they have been formed, some antibodies persist through-
out the life of the individual. This is referred to as lasting
or permanent immunity. On the other hand, some antibodies
disappear from the blood stream as soon as recovery from dis-
ease is brought about. Diseases. consequently, which produce
antibodies that are easily disassociatable may He had an.y num-
ber of times, and life immunity will never result. Influenza
may be cited as a disease of this sort, since an individual may
contract it any number of times. Diphtheria may. on the
other hand. be cited as an example of a disease which produces
life immunity in all who recover from it. since no individual
may have it more than once.
Strange as it may seem, the worst disease in the world is
malaria. It has been estimated that this disease alone costs
the South $2,000,000.00 per year in loss of human efficiency.
In India it is responsible for the death of 1,000,000 persons
each year. Malaria is produced by a one called animal para-
site of which three or four species are infectious to man.
These are Plasmodium vivax. Plasmodium falciparum. Plas-
modium malariae. and possibly a fourth species called Plas-
modiui ovale.
The malaria parasite has two separate and distinct life
cycles. One of these occurs in the blood stream of man and
a few of the higher vertebrates. and the other occurs in the
body of a mosquito. The mosquito may. therefore, he referred
to as a carrier of malaria. The mosquito most often incrimi-
nated in the transmission of this disease is Anopheles quadri-
maculatus. However. various other species of the genus An-
opheles (such as A. crucians. A. pI)nctipenis, etc.). are known
to be carriers.
There are parasitic plants which fasten themselves in the
skin and produce irritation. Ringworm, thrush, alopecia, and
a number of other diseases are caused by plants.





DEPARTMENT OF AGRICULTURE


The study of medicine has beeli mostly empirical-by ex-
perimental observation-and with very little scientific basis.
Most of the advance made in scientific medicine is the result
of the discovery of the germ theory of disease, and this dis-
covery is due to bacteriology. The science has borne its most
beneficial fruits in the line of preventive medicine and
hygiene.
In contagious diseases what is needed is a germicide that
is harmless to the human body and that can be introduced
into the circulation. Pasteur said that each contagious dis-
ease is caused by a pathogenic germ or germs which may be
identified. He predicted that a universal germicide would
be discovered, harmless to human beings, and that thereafter
no one need contract disease by infection, and that contagion
would be impossible in the presence of such an universal
germicide.
Inasmuch as a germicide that would destroy plant germs
might not destroy animal organisms, it might not be possible
to have a universal parasitic specific. But if a germicide can
be found that is harmless to animal organisms, but which
destroys all vegetable germs, it would mark the greatest stride
in remedial science. The production of such a germicide is
claimed for the invention of William John Knox of Ann Arbor.
It produces scientifically a germicidal vapor which is respirable.
It is a chemical product produced by a union of ozone and
vapor of pinene. Atmosphere is introduced into the machine
and dried, coming in contact with electric volts gauged to rule,
when ozonized and vaporized it is expelled in the form of
vapor, the formula of which is CloHioOs-a gaseous pinene
ozonide.

CHAPTER II
INSECTS AND SPRAYS

Mistakes Often Made
1. Treatments are often made for troubles which are in-
curable; consequently no results could possibly be obtained
from any operation which might be attempted against them.





P)l1ANT DXlsEA-SE AND PESTS


2. Treatments are often given where there are no needs
for them. When first starting to control insects many people
get the idea that they must spray even if they do not know
whether a pest is present or not.
3. Expensive methods are often used when cheaper ones would
serve the purpose equally as well. Even when a cheap method
is used. it caIn be so manipulated that maximum results may
he obtained witli a minimiuim expense.
4. The wrong time is chosen to make the appllication for
many insects. It is necessary to understand the general prin-
ciples of the life history of a pest in order to make timely
treatments for it.
5. The improper selection of the material to use against
an insect is the most common mistake that is made. As will
be clearly shown later, it is not possible to kill sucking insects
by tlhe use of poison.
6. Too often the grower unknowingly purchases an inferior
grade of spray material. The grower must insist on a gJood
grade of spray material. since Ine is paying good money and
can rightfully demand the best.
7. The use of a spray outfit not adapted for the particular
operation, and tlie improper use of a goo{I outfit. are the
causes of much failure. There are accessories for use with
spray outfits that will greatly simplify the operation.
If some of these comnlnon mistakes are guarded against there
is no reason why more satisfactory results cannot be obtained
inll tle slraying operations against insert pests. Local experi-
ence is really tle sure gauge for successful spraying operations.

INSECTICIDES
Materials which are used to destroy insects are called in-
secticides. They may be divided into four classes:
1. Poisons which kill by being eaten and usually contain
some form of arsenic; so are often called arsenicals.
2. contactt insecticides -which kill by clogging up tle
breathing. system iby surrocation or by a corrosive action on
the skin.




DEPARTMENT OF AGRICULTURE


3. Repellents-which keep the insects from attacking the
plant or animal to which they are applied.
4. Gases-which are used for fumigating.
Poisons
Poisons are the cheapest form of an insecticide. They are
applied to the food of the insects and must be eaten to be
effective. It is evident that poisons are effective only against
biting insects, which go beneath the surface of the plant for
their food. Nearly all of the poisons are made from arsenic
and consequently are termed "arsenicals." The amount of
arsenic varies with the different poisons, but the standard
for each is set by law. Arsenicals are insoluble in water, and
it is necessary constantly to stir a liquid spray to prevent the
poison from settling. In some of the arsenicals there is a
small quantity of what is termed "water-soluble" arsenic..
Such arsenic will readily combine with water, and when such
a combination takes place heat is given off. It is in this way
that the foliage of plants is burned when such sprays are
applied. The poorer grade poisons contain more water-soluble
arsenic than the better grades. With those poisons which con-
tain this water-soluble arsenic it is necessary to add lime to
prevent or reduce the burning of the foliage. Most of the
arsenicals may be used either as a dry or dust spray, or as a
liquid spray.
White Arsenic
This material should never be used as a spray to put on
plants, since it severely burns all tissue that it comes in con-
tact with. The only place it can be safely used is in making
poisoned baits for grasshoppers and cutworms. It is the cheap-
est form of poison that can be purchased.
London Purple
This material is so variable in composition that the results
obtained by its use have been very unsatisfactory. It should
never be sprayed on any plants since it will severely burn the
foliage. It is possible to use this material in the poisoned
bran mashes, but it is seldom recommended. The upe of London
purple has been discontinued for many years in progressive
spraying sections of the country.





PLANT DISEASES AND PESTS


Paris Green
From the beginning of the spraying practice Paris green
has been the only material that was generally recommended.
However, it has not given entire satisfaction. When used
as a liquid spray it settles very quickly and causes an uneven
application. It does not stick well on the foliage, and as it
contains a considerable amount of water-soluble arsenic, it may
burn the foliage of the plants to which it is applied. As a
spray material Paris green has practically gone out of use.
Liquid Spray.-Never more than one-half pound of Paris
green should be used for fifty gallons of water, and when one
is spraying tender plants, such as the peaeh, only one-fourth
pound should be used. The Paris green should be thoroughly
mixed into a thin paste and then added to the water. This
insures a better mixing of the powder and water. To neutral-
ize the action of the water-soluble arsenic it is necessary to
add two pounds of good stone lime to every fifty gallons of
water.
Under some conditions it is advisable to use a combined
spray of a poison with a fungicide. When Paris green is used
in combination with Bordeaux mixture, the same amount is
required for fifty gallons of Bordeaux as for fifty gallons
of water, and it is not necessary to add the lime.
Dry Spray.-For many crops it is not advisable to use a
liquid spray. Paris green may be applied as a lx>wder, but it
must be dusted with eight or ten times its weight of flour or
air-slaked lime, preferably the latter. As it is usually best to
apply a dry poison when there is some dew on the plants, and
since dew will combine with the water-soluble arsenic. there
is certain to be considerable burning of the leaves from the
use of this spray upon cotton. Tihe cotton plant is particularly
sensitive to burning by Paris green, and for that reason it is
not recommended now for use on cotton.
Arsenate of Lead
This material is now almost universally used as a poison
spray. It is possible to make this material at home, but the
commercial preparations are to be preferred, as the contents
of the product are guaranteed. This poison is available to





DEPARTMENT OF AGRICULTURE


the grower in two forms-paste and powder. The cost of the
powder is somewhat higher than that of the paste, but the
cost of the spray made from either is about the same. This
poison is far superior to Paris green, as it does not settle so
quickly in the spray tank, is much more adhesive to the foliage,
and does not burn the plants; so there is no need for the
addition of lime to the spray. The action of this poison is
somewhat slower than that of Paris green but certainly as
effective.
Liquid Spray.-For a liquid spray either the paste or
powdered form of arsenate of lead may be used; three pounds
of the paste or two pounds of the powder are required for
fifty gallons of water. Mix the required amount of paste or
powder into a thin paste before adding to the barrel of water.
It is also possible to use this poison with the Bordeaux mix-
ture, the same proportion being used as suggested for water.
Dry Spray.-When a dry spray is desired the powdered
arsenate of lead may be used without the addition of any other'
material. The powdered arsenate of lead is recommended for
use on cotton against all chewing insects.
Zinc Arsenite
This poison is comparatively new, but the results which
have been obtained, from it thus far indicate that it may be
superior to any other poison now on the market. The great-
est feature of this poison is that it is very adhesive to the
foliage.
There are two materials which are poisonous to insects but
not to higher animals unless taken in quantities. These are
hellebore and pyrethrum or Persian insect powder.
Hellebore
Ilellebore is a white powder made by grinding the roots of
the hellebore plant. This powder loses its strength rapidly
and must be fresh to be of any value. It may be used as a
dry or liquid spray. If a dry spray is desired, mix the helle-
bore with flour at the rate of one to three pounds, respectively.
For a liquid spray use one ounce of hellebore to three gallons
of water. As the hellebore loses its poisonous properties





P LAN'T' 1)TSEASES AND) mwEs'


quickly, it may be safely applied to fruits and vegetables just
before harvest.
Pyrethrum
Pyrethriium is. a yellowish powder made by grinding thll
dry flowers of the plant. The destructive power of this material
is due to an essential oil. It may be used in the same manner
as suggested above for hellebore and inl the same proportions.
This material is also valuable as a spray for fruits and vege-
tables that are ripeniing If one will close up rooius that are
infested with flies anid mosquitoes and Ihei fill (lie air with
pyrethllruin and keep thle rooms closed over night. almost of tihe
insects will either be killed or stlupefied anld (drop toI lthe floor.

Poison Bran Mash for Grasshoppers
Probably tle lest poisoni for this purpose is called "Kalnsias
( rasshopper Poisoln." This is nimade as follows:
HB anl .................... ............................ ............................................... 20 pol nd s
I'lParis green. or white alseni ........................................ .. 1 po d
Sy lrli' p ......................... .............................................................. .......... 2 qullarts
L eiolllo 1 ......................................................................... ................ . :3
W atel. ..................................................................................................... gallons

To prepare this mash lix tile bran and the poison thoroughly
in a wash tub whlile dry. Sqleexe te jlie iieo of the leilons into
the water and chop thie pulp and peel into fine hits and add to
the mixture. Dissolve the syrup in the water and then wet
the bran and poison with the mixture. stirring so as to dampen
the mash thoroughly. The amount of 'water here riven is
.sufficient to properly moistenii tle bratn.

Poisoned Baits for Cutworms
In addition to tlie Kansas yrasslhopper poison. which is sui'-
cessful against cutiwlor-ns,. the following poison maslh gives
excellent results:

W heat or rice bran .................... ............ ............ po11 unds
Arsenic or Paris green ....poi......d... ................ 1 pound
M olasses ........ ...................................................... 1 art
Water to moisten.





DEPARTMENT OF AGRICULTURE


Mix the poison and the bran together dry. Dilute the
molasses in a gallon or two of water and add it to the poison.
Mix thoroughly and add only enough water to make the mix-
ture moist but not sloppy.

Poisoned baits of clover are often successful against cut-
worms. For this purpose cut a small quantity of clover or
alfalfa and chop this into rather fine bits. Then spread it out
and spray with Paris green at the rate of one-fourth pound
to twenty gallons of water. After the poison is dry on the
clover it is ready to be distributed in small bunches around
the base of the plants that are liable to attack by the cut-
worms. This poisoned clover should be made late in the
afternoon and distributed just before dark so that it will be
attractive to the worms when they come from their hiding
places at night.

Caution.-These particles of clover or alfalfa which have
been sprayed will retain the poison for some time. If the
worms do not eat this freely it should be collected and burned
and not allowed to dry up and blow around where stock and
poultry may get it.
Ant Poison
The following formula is especially valuable against those
ants which are attracted to sweets. This formula is best
prepared by a druggist:
White Arsenic ..../...... ................. 4 gram
Cane sugar ................. ............ 20 grams
Water -.............................--.......100 c.c.
The arsenic is dissolved in a portion of the water by boiling
and the sugar in the remaining portion. The two solutions
are then mixed and water is added to make up for the evapora-
tion. Some color of fruit paste should be added to warn of
the poisonous nature of this solution. For use this poison may
be put in shallow dishes which are placed in the locations
frequented by the ants. The use of this poison is not advisable
where there are small children in the home.





PIl.A 'I' I)-SEASE I) IAED'P'S


CONTACT INSECTICIDES
contactt sprays are applied to the insects and only inci-
dentally to the plants. With these the great aim is to apply
the material so carefully that it will certainly come in con-
tact with all the insects, as a mere spraying of the foliage
is of no value whatever.
Lime-Sulphur Wash
The lime-sulphur wash has always been the standard
remedy for the San Jose scale. and during the last few years
has come into wide use throughout the country. The lime-
sulphur wash is a chemical combination of the lime and the
sulphur. It has also been found to be an efficient fungicide,
and the spring applications just before the buds start are
very effective in killing the winter spores of various fungous
diseases.
The material is used both as a winter spray. when the
trees are dormant, and as a sullmmer spray: I)llt tile solultionll
for the summer is much weaker. Materials of the proper
strength for winter use must never be used on trees that are
in 'leaf, as it will burn the foliage. The most effective season
to apply the winter strength of lime-sulphur is the early
spring, just before the buds begin to swell. It may be applied
in the fall, however, any time after the leaves drop.
There are three ways of prelpari.ng the winter wash of
lime-sulphur: by diluting the commercial concentrated solu-
tion to the required strength: by making a concentrated solu-
tion at home, and diluting when needed, and by making a
solution which. when finished, is ready for use without dilut-
ing.
Commercial Concentrated Lime-Sulphur
The leading manufacturers and dealers in insecticides are
now selling a concentrated lime-sulphur solution which
is made ready for use by merely diluting to the desired
strength. This is sold at a price that makes the final product
cost 21-I to 3 cents per gallon.-nearly as cheap as it can be
made at home and with the saving of time and a disagree-
able job.





DEPARTMENT OF AGRICULTURE


Commercial concentrated lime-sulphur is a clear, reddish-
brown liquid. For use, this material is simply diluted with
water. The amount of water to be added is usually indicated
on the container, but it is best to test the strength. This is
done with a hydrometer, which will indicate the specific
gravity. These hydrometers, made especially for testing the
lime-sulphur mixture, may be obtained from Bausch & Lomb
Optical Company, Rochester, N. Y., and other dealers in
laboratory glassware. The dilutions should be made accord-
ing to the table given later.
Since the spray is quite clear it shows but little on the
trees. Some prefer to add lime to the material after it is
ready for the spray tank, but the lime should be added before
the final straining. For this purpose either lump or .air-
slaked lime may be used, at the rate of six to eight pounds
to fifty gallons of the spray. There is no real advantage in
adding the lime, but it is easier to tell when the tree has been
well coated with the spray.
Home-made Concentrated Lime-Sulphur
If suitable appliances are at hand it is feasible to make lip
concentrated lime-sulphur at home, which can be diluted for
use when needed. It is absolutely necessary to keep the
finished product sealed from the air. It is also essential that
the purity of the materials to be used are guaranteed, and it
is highly important that only the best grade of lime should
he used. Lime which is less than 90 per cent pure should be
discarded. In most cases it will be found that the commer-
cial concentrate is safer to use.
The New York Experiment Station 'has made extensive
experiments on the best methods of making and diluting lime-
sulphur, and the following is quoted:
Geneva Station Formula for Making Lime-Sulphur
Lime, pure ...... ....................... 36 pounds
Lime, 95 per cent pure ............................. 38 pounds
Lime, 90 per cent pure ...- -..... .................... 40 pounds
Sulphur, high grade, finely divided ............ 80 pounds
W ater ............................................. .................. 50 gallons





PLANT DISEASES AND PESTS


In making, slake the lime in about ten gallons of hot
water, adding the lumps slowly so as to avoid too violent
boiling. The sulphur must he well moistened and made into
an even paste without lumps. Then pour the paste gradually
into the slaking lime. stirring constantly to prevent the forma-
tion of lumps. When the slaking has finished add the full
amount of water and boil gently for an hour. If kettles and
fire are used, water must he added from time to time to make
up for the loss due to the evaporation.
It is much better if the cooking can be done with live steam
in a closed vessel. but an open fire will do. When the boiling
is done in this way thie mixture will be more likely to increase
the volume and it will not he necessary to add any water.
Regular Home-Made Lime-Sulphur Solution
Lime (good stone . 20 pounds
Sulphur 15 pounds
Water 50 gallons
This material when finished is of the proper strength for
use as a winter spray without any further dilution. It con-
tains much sediment and must always be carefully strained
before use.
Place the stone lime in an open iron kettle and add a few
gallons of hot water: then gradually add sulphur. which has
been made into a paste. Add about twelve gallons of hot
water and boil hard for an hour, stirring constantly. Dilute
with enough water to make fifty gallons.





30 DEPARTMENT OF AGRICULTURE

Dilutions for Dormant and Summer Spraying with
Lime-Sulphur Mixtures

Amount of Dilution. Number of Gallons of Water
to One Gallon of Lime Sulphur Solution
Reading on
Hydrometer
Hydrometr oan Joe For Summer
Scale of Winter For BlDter Spraying of
Strength Mite Apples
36 ........................... 9 12%1 45
35 -------------------------- 89 12/. 45%
35 .................................. 83/ 12 431/2
34 ........ .... ..... 84 11 411/2
33 ...... .......................) 8 11 40
32 .. -- .-.....-..... -- 71/ 101/, 37%
31 ............................... 714 10 361/
30 ...... 63/ 91/2 341/4
29 .......................... 6 9 32%
28 ..- - .......-. .- 6 81/ 31
27 ..................... ... 5% 8 291/,
26 .... ....... .... ...... 5 71/ 27%/
25 ..... .................. 5 7 26
24 .......................... 4 61/2 241/
23 .... .............. .-..... 4%4 6 223/
22 ...................... ..... 3% 5%1/ 211/
21 . .................... 31/ 5 1934
20 ................... ; 31 % 4% 1814
19 ............ ..... 3 41/4 17

Kerosene Emulsion
Kerosene emulsion is a very valuable insecticide for the
destruction of sucking insects, such as plant-lice, scale-insects,
etc., and for the destruction of insects hibernating in rubbish
or collected in large masses on tree trunks, etc. Kerosene
emulsion is not a poison, but kills by closing up the spiracles
or breathing pores of the insects. The ingredients of the
emulsion are kerosene, soap, and water in the following pro-
portions:
Laundry soal) .... ............ ......... 1 pound
Boiling water ..- ..................... gallon
Kerosene .. ........2 -..................... '2 gallons





PLANT DISEASES ANI) PESTS


A low grade of kerosene. which is cheap. is as satisfactory
as the higher priced illuminating oil and, if desired, soft soap
may be substituted for the ordinary laundry soap.
The soap forms a coating around each minute particle of
oil "emulsifying" it and permitting of its then being dissolved
or diluted with water. Both the soap and oil are active agents
in destruction of the insects.
Preparation.-To prepare the emulsion, shave one pound
of laundry soap (or soft soap) into one gallon of soft water
(rain water). Have the water boiling hot. As soon as the
soap is all dissolved remove the solution from the fire and
add the two gallons of kerosene. At once agitate the ma-
terial violently. Continue for at least five minutes. This
is best done by the use of a bucket spray pump: turn the hose
or nozzle back into the bucket or tub so that the material is
constantly forced vigorously through the pump. In a few
minutes a smooth, creamy emulsion is formed, without any
free oil. This will get thicker as it cools. hit if it is properly
made no free oil will separate out. This is the "stock solu-
tion" and will keep indefinitely if sealed from the air. (Do
not try to make the emulsion by stirring with a paddle, or
similar means, for this does not cause sufficient violent agita-
tion to thoroughly emulsify the oil.)
Dilution.-For use on trees or shrubs that are dormant,
the stock solution may be diluted with five to seven parts of
water, forming a spray containing 8 to 11 per cent of oil. On
trees or plants that are in leaf, one should dilute the stock
solution with ten to fifteen parts of water, thus making a
spray containing 4 to 6 per cent of oil. Soft-bodied insects.
such as plant lice. are usually killed with a 5 to 6 per cent
solution. The following table shows how to dilute the stock
solution to secure any desired per cent of oil:
For 4 per cent. strength, add 15 2/3 gals. water to I gal stock solution.
For 5 per cent. strength, add 12 1/3 gals. water to I gal. stock solution.
For 7 per cent. strength, add 8 1/2 gals. water to I gal. stock solution.
Por 10 per cent. strength, add 5 2/3 gals. water to I gal. stock solution.
For 12 per cent. strength, add 4 1/2 gals. water to 1 gal. stock solution.
For 15 per cent. strength, add 3 1/2 gals. water to I gal. stock solution.
For 20 per cent. strength, add 2 1/3 gals. water to I gal. stock solution.
Kerosene emulsion is best applied on bright, sunny days
when the wind is blowing, since a considerable quantity of





DEPARTMENT OF AGRICULTURE


the oil will evaporate quickly, and the danger of injury to the
plants will thereby be reduced.

Commercial Tobacco Extracts
There are now on the market highly concentrated extracts
of tobacco. For use these liquids are diluted with water ac-
cording to the concentration of the brand and the insect which
is to be killed. Usually the tobacco sprays will spread more
readily and evenly on the plants if soap is added to the solution
at the rate of one pound to.fifty gallons. It has been found
that strong tobacco sprays may kill the eggs of some plant-lice.
The weaker dilutions of tobacco extracts are especially valuable
for destroying soft-bodied insects, as plant-lice. "Black Leaf
40," "Nico-Fume," "Sulphate of Nicotine," and "Black Leaf
Extract," are some of the trade names for the tobacco extracts.
The cost of these extracts may seem prohibitive, but when
diluted the spray is not any more expensive than other materials
for the same purpose.

Home-Made Tobacco Extracts
It is possible to make an extract at home from the tobacco
stems or dust. Place one pound of the stems or dust in one
gallon of water and heat to just the boiling point for one hour,
making up for any loss of water. This solution should never
be allowed to actually boil, as some of the active principals
will be lost in the vapors. Dilute this mixture with two parts
of water and add soap at the rate of one pound to fifty gallons
of spray.

Whale Oil Soap
Whale oil or fish oil soap is commonly found for sale in
the hard form, made from caustic soda. The potash soaps
are much to be preferred, as they dissolve more readily in
water. This soap solution is especially valuable for use against
soft-bodied sucking insects, but it is not generally effective
against the more resistant sucking insects. For plant-lice, dis-
solve this soap in water at the rate of one pound to seven
gallons. The hard soap must be shaved into a small quantity





PLANT DISEASES AND PESTS


of boiling water ain tile mixture stirred for some time. After
the soap has been dissolved. cold water may be added to make
tihe above formula.
Laundry Soap
If whale oil soap is not available, it will be found that a
simple solution of laundry soap is very effective for spraying
plant-lice. Any good grade of laundry soap may be used for
this purpose. The formula of one pound to seven gallons of
water has proven very effective against plant-lice. ILaunnd(ry
sc:ap does not dissolve readily, and it is best to shave it into a
liberal ilquantity of boiling watlir andI stir freulleltly. When
tile dissolution of the soap is eomlplete. cold water Ilmay Ih
added to make tlhe above formula.

Sulfur
Dryv siul ur or 1p;wdered suilfunl. sometimes called flowers
of sulfur. is often used as a contact insecticide. especially
against tihe red spider. The dry suilfuir should be thoroughly
dusted over the foliage in an effort to hit all tihe spiders. It
is best to apply sulfiuir w\henl te foliage is moist with dew.
1lydrated lime mixed in equal parts with tle sulfur will make
it more adhesive. Silfur Ibecomes effective only when the
still vaporizes it; so if appliiedl wheni tlhe sun is niot slhiingll it
will remain inletive until tihe first bright day.

Repellents.- A repellent is anlty material which is applied
to a plant or animiial that may be of sitervice in driving away
any insect that mightt attiak it. l)Dry air-slaked lime is of
service ill driving away sone pests. It should lite ldusted directly
on the insects which are feeding upon the plant. Tobacco
dust acts as a repellent to some insects, especially the root-
feeding insects. Naphthalene flakes or moth balls act as a
repellent for insects that infest stored iprod(cts. Biordeaux
mixture, ia ftniiniidle, acts as a repellent for ILmany insects.
especially for some forms which feed upon potatoes and
tomatoes.. The various fly sprays which are applied to stock
merely act as reel)lelnts.





DEPARTMENT OF AGRICULTURE


Protective Tree Wuheu
1. Dissolve one pound of hard soap in three gallons of
water. Add one-half pint of crude carbolic acid and two
ounces of Paris green. Then add enough lime to make a thick
paste, such as will be easy to apply to the trees.
2. Dissolve sixteen pounds of hard soap in eighty gallons
of boiling water. Then add two quarts of crude carbolic acid
and enough freshly slaked lime to make a thick paste.
:. Slake one bushel of lime in a small quantity of warm
water. Add ten pounds of sulfur, which has been previously
made into paste. Then add one-half gallon of gastar and dilute
with water to fifty gallons.
4. Dissolve seventy pounds of quicklime in fifty gallons
of water. Add six pounds of caustic potash and two and one-
half pints of crude carbolic acid.
These washes should be painted on the trunks and lower
limbs of the trees, and the application should be very thorough
to be effective. Every small crevice in the bark should be
well coated with the wash. Unless rains occur immediately
after the application is made, two or three applications will
be sufficient during the summer.
Fly Repellents
There are a great many home-made and proprietary external
remedies for repelling flies from stock. Many of them have a
value, but many more are of no service whatsoever. The most
common defect of many of the repellents is the very short
period during which they are effective. Some repellents are
undoubtedly poisonous and should be used with extreme care.
The qualities to be sought in a satisfactory repellent, are
absence of toxic or other detrimental properties, a decided
repellent action on the flies, and a long period of effectiveness.
The following has given satisfactory results over the country:
No. 1 The Moore formula:
Fish oil __-__ _100 parts
Oil of tar ..... ....... .............. ....... ...... .. 0 parts
(rude carbolic acid ----- 1 part





P LANT I)SMEASES AND) PESTS


No. 2. The Bishop formula :
Fish oil .. ............ ........... 1 gallon
Oil of tar .---....................... ................. .. ounces
Oil of pennyroyal ................. .. ......- 2 ounces
Kerosene --... ........ ................ 1 pint
This mixture is very effective in keeping flies from live
stock when applied lightly with a brush.
No. 3. The Parrott foriuila :
Fish oil .. .. .... .......... 2 quarts
(rude carbolic acid ........ 1 pint
Oil of pennyroyal .. ....... 1 ounce
Oil of tar ......... .... .. ounces
Kerosene sufficient to make one gallon of Ihe mixture.
The cost of this is given at 80 cents a gallon. It must be
applied with a hand atomiizer and niot with a brush.
Fumigants
Fumigation is available only for insects that can be treated
in an enclosed space. This method is good for the treatment
of pests which attack stored products an(d for gr'eehllo(sIse
pests.
Carbon Bisulphide
This material is most extensively used against insects which
attack stored products. Household goods may be fumigated
with this material if the proper precautions are taken. It is
used to some extent for root-feeding insects by injecting it
into the soil. ('arbon bisulpfhide is a clear. yellow liquid with
a very strong and disagreeable odor. When exposed t to the air
it evaporates very quickly and the fumes being heavier than
air go to the hottoml of tlie enclosed space. The fines are not
so effective below temperatures of 60" F. and a larger dose
is required under such conditions. Any material to be fumni-
gated sholild be placed i'n as small a space as possible, since
it is the confined area and not the contents that determine
the dosage. The hisulphide should always be put in shallow
dishes and placed on top of the material that is to be fumni-
gated. The amouniit of bisulphide Inecessary for a single appli-





DEPARTMENT OF AGRICULTURE


cation varies considerably according to the insect that is to be
killed. One pound to a thousand cubic feet is sufficient for
many insects, but as much as ten pounds is required for others.
Do not allow any fire or source of fire, as a lighted cigar,
to be near the fumigation or the stored bisulphide. The fumes
from carbon sulphide are highly inflammable and under cer-
tain conditions explosive. Use the same precaution in handling
this material that would be used in handling gasoline. The
fumes should not be inhaled as they cause suffocation which
results in dizziness.
Carbon Bisulphide Emulsion
Carbon bisulphide emulsion consists essentially of seven
parts of carbon bisulphide and three parts of an emulsifier.
The emulsion is used at the rate of one quart to fifty gallons
of water and this diluted mixture is applied at the rate of
three pints to the square foot of surface. In making the ap-
plication one-half the required amount is applied and after a
few minutes the remaining half is put on. The ground tem-
perature should be above 45 degrees F. The dosage must be
exact since an under-application will not kill the grub and
an over-application may produce serious burning to the
grasses.
Pa. Bul. Vol. 12 No. 4, April 1, 1929. p. 14. The Japanese
Beetle in Pennsylvania.
Sulphur
The fumes of burning sulphur have long been recognized
as a standard remedy for the fumigation of dwellings. It is
an excellent remedy for bedbugs in empty houses. The seri-
ous objections to the use of sulphur fumes are: they will
bleach fabrics; they will tarnish brass; they will destroy
vegetation, and they will destroy the germinating power of
seeds.
Tobacco
For fumigating greenhouses tobacco fumes are universally
used. This material can be employed where the most tender
plants are grown, and it is especially effective in controlling





P LANTI DI8EASE-'HS AND PESTS


plant-lice. .Many outdoor plants. as melons, and low shrubs
or trees, may be fumigated with tobacco fumes by means of
especially constructed covers. The methods of fumigation
are to burn tobacco stems, or dust. or to vaporize some of the
liquid extracts, or to burn some of the punk papers now for
sale. This last method is most satisfactory as it is possible to
designate the proper amount of paper to be burned in a given
confined space.
Hydrocyanic Acid
This is the most alive fumigant known. It i.-i made by cotm-
bining water. siilph'rie aeid. and potassium cyanide. This
gas is a deadly poison to all plant and animal life. and it
should not be used unless the operator has had experience or
unless proper directions are carefully followed.



STANDARD SPRAYS AND SOLUTIONS USED IN THE
OVERCOMING OF PLANT DISEASES
Bordeaux Mixture is rsed for the control of fungous dis-
eases of maiiny vegetables and fruits and as a deterrent of
flea-beetle attack. It can lie purchased in convenient pack-
age form from seed dealers or prepared at home from blue-
slone (copper sutlphate). and fresh stone or lump line (quick-
lime).
Dissolve thle blilestone in ai wooden or earthenware vessel,
using hot water. Dilute with half thlie water. I)o not use tin
or other metal containers, as they would lie spoiled. Slake
the lime by adding water. a little at a time. When reduced
to a milky fluid, dilute with the rest of the water and strain
throighi double cheese-cloth or a brass wire strainer of IS
meshes per inch anl(id pour into it the bluestone solution. Stir
well and apply at once." This is best when prepared fresh for
each using.

Mercuric chlorid (corrosive sublimate) is used for treat-
ing,, seed potatoes and cabbage seed for diseases. It may v be
purchased at drillug stores in the formi of tablets. I)issolve two





DEPARTMENT OF AGRICULTURE


large tablets in a quart of water to make a 1 to 1000 solution.
For larger quantities use 21/ ounces to 15 gallons of water.
Corrosive sublimate is a deadly poison. It attacks metals and,
therefore, must be used only in a wooden, glass, or earthenware
vessel.
Formaldehyde (formalin) is used for treating seed po-
tatoes, seeds, and soil, to prevent diseases. This is a clear
solution of 40 per cent formaldehyde gas in water. It is very
irritating to the eyes and to cuts, but not poisonous. It does
not attack metals. Use teaspoonful to a teacupful of water,
1 ounce to 2 gallons of water, and 1 pint or pound to 30 gal-
lons of water (for potatoes and onions). It is not an insecti-
cide.
Lime is used to control cabbage clubroot. It neutralizes
soil acidity and therefore tends to increase scab on potatoes.
It acts at the same time to a limited extent as a deterrent
against certain insects which may be in or on the soil, such
as maggots and grubs, and is a good remedy for slugs. Air-
slaked or hydrated lime is the best form to use.
Lime-sulphur is a valuable spray for fruit trees applied
during the dormant season, but not suited for use on vege-
tables. Experiments have shown that potatoes are injured
rather than benefited by it.
Methods Successfully Used in Sterilizing Seed Beds
Steam tile are used to sterilize the soil by placing lines of
2-inch to 3-inch glazed tile lengthwise in the beds to be steril-
ized, 2 to 21/_ feet apart and 15 inches below the surface, and
these are left there permanently. They provide drainage for
the beds, may be used for subirrigation, and are available at
any time for sterilizing the soil, the only labor being the cov-
ering of the beds with boards or tarpaulin and the connecting
of the tile with a boiler by means of a piece of steam hose. It
is advisable to spade up the soil, so that the steam may more
readily penetrate it.
Steam pans furnish another method of steaming, by means
of admitting steam under inverted galvanized iron pans. 6 by





PLANT J)lXEDSSAS AND) POSTS


10 feet and 6 inches deep. This has been used in the sterilize'
tion of tobacco seed beds and in gKreenhiiouse beds. and lilas
given very satisfactory rellts. The use of steamn at pressure
of 80 to 100 pounds and treatment for half an hour to an hour
after the soil has reached a temperature of 212'F.. as indi.
cated by soil thermometers, hlils given the best results.
Formaldehyde sterilization is accomiplislied by drenclhing
the soil with a I to 100 or 1 to 20) solution of standard for-
maldehyde (40 per cent), at the rate of :Ij of a gallon per
square foot of urea. several days before tlie soil is to be used.
Formaldehyde. however, does not rid tlie soil of nematodes.
as steaming does. This method has been used to excellent
advantage in the sterilization of lettuce beds for the preven-
tion of fungous diseases.


FUNGICIDES AND INSECTICIDES
Many of these mixtures can be obtained already prepared
from reliable dealers, whiehi saves much time and trouble in
mixing them. lThe following precautions should he taken into
consideration:
1. (are should ble taken to keep all isubstancee employed
in spraying where they cilnnot he gotten at anl( used Iby mis-
take. All sul)bstances should he correctly labeled.
2. Solutions and mixtures containing copper sulphate. cor-
rosive sniblimate and arsenate of lead should le made in wood.
glass or earthen vessels.
:1. Arsenical solutions should not I.be applied to fruits. etc..
within two weeks of the time they are to be used as food.
4. Trees should not be sprayed when they are in blossom.
its the bees. which are necessary to fertilize the flowers. may
e(, destroyed.
.. Florida growers interested in spraying and other means
of checking insect pests. not fully covered herein, should write
the director of the Florida Experiment Station at (hiinesville,
for furtherii information.





DEPARTMENT OF AGRICULTURE


Bordeaux Mixture
4 pounds copper sulphate (blue vitriol).
4 pounds lime unslakedd).
25-50 gallons of water.
Dissolve the copper in hot or cold water, using a wooden
or earthen vessel. Slake the lime in a tub, adding the water
cautiously and only in sufficient amount to insure thorough
slaking. After thorough slaking, more water can be added
and stirred in until it has the consistency of thick cream.
When both are cold, pour the lime into the diluted copper
solution of required strength, straining it through a fine-
mesh sieve or a gunny cloth, and thoroughly mix. The stand-
ard mixtures are:
(a) 25 gallons (full strength solution, or 4-4-25 formula).
(b) 50 gallons (half strength mixture, or 44-450 formula).
It is then ready for use. Considerable trouble has frequently
been experienced in preparing the Bordeaux mixture. Care
should be taken that the lime is of good quality and well
burned, and has not been air-slaked. Where small amounts
of lime are slaked, it is advisable to use hot water. The lime
should not be allowed to become dry in slaking, neither
should it become entirely submerged in water. Lime slakes
best when supplied with just enough water to develop a large
amount of heat, which renders the process active. If the
amount of lime is insufficient, there js danger of burning
tender foliage. In order to obviate this, the mixture can be
tested with a knife blade or with ferro-cyanide of potassium
(1 oz. to 5 or 6 ozs. of water). If the amount of lime is in.
sufficient, copper will be deposited on the knife blade, while
a deep brownish-red color will be imparted to the mixture
when ferro-cyanide of potassium is added. Lime should be
added until neither reaction occurs. A slight excess of lime,
however, is desirable.
The Bordeaux mixture is best when first prepared. Stock
solutions of lime and copper can be made and mixed when
required.




PLANT DISEASES AND) PESTS'


The following, known as the 6-4-50 formula, is in very
general use:
6 pounds copper sulphlate.
4 pounds lime.
50 gallons water.
Bordeaux Mixture for Peach Foliage
The Bordaeux mixture, as ordinarily applied. frequently
injures to some extent the foliage of the peach, etc.. causing
a shot-hole effect on the leaves. This injurious effect has been
shown to he largely obviated by the use of the following:
3 pounds copper sulphate.
6 pounds lime.
50 gallons water.
This is known as the 3-6-5i0 formula. Some experimenters
have also recommended the following for peach foliage:
(a) 2-2-50 formula (Cornell A.\r. Exp. Sta. Bull. 180).
(b) 3-9-50 formula.
The latter contains three times as much lime as copper
sulphate.
Bordeaux Resin Mixture
5 pounds resin. I pint fish oil.
1 pound potash lime. 5 gallons water.
To make resin solution, place resin and oil in a kettle and
heat until resin is dissolved. ('ool slightly and then add lye
slowly and stir. Again place the kettle over the fire. add the
required amount of water and allow the whole to boil until
it will mix with cold water, forming an amber-colored solu-
tion. 'ake 2 gallons of the resin solution and add to it 10
gallons of water. Mix this with 40 gallons of Bordeaux mix-
ture.
Recommended for asparagus rust on account of its ad-
hesive properties. (N. Y. Agr. Exp. Sta. (Geneva) Bull. 188).
Saccharine of Copper
4 pounds copper sulphate. 4 pints molasses.
4 pounds lime. 25 gallons water.




DEPARTMENT OF AGRICULTURE


Slake 4 pounds of lime and dilute the same with water.
Dissolve 4 pints of molasses in a gallon of water and mix with
the lime. Stir thoroughly, and let it stand for a few hours.
Dissolve 4 pounds of copper in 10 gallons of water and pour
it into the lime-molasses solution, while stirring briskly.
Allow the mixture to settle. Draw off the clear, greenish
solution for use. Recommended in France as a substitute
for the Bordeaux mixture.
Ammoniacal Copper Carbonate
5 ounces copper carbonate.
3 pints ammonia (260 Beaume).
50 gallons water.
Dissolve the copper carbonate in ammonia. This may be
kept any length of time in a glass-stoppered bottle and di-
luted to the required strength. The solution loses strength
on standing.
Eau Oeleste
(Blue Water)
2 pounds copper sulphate.
1 quart ammonia.
50 gallons water.
Dissolve the copper sulphate in 6 or 8 gallons of water;
then add the ammonia and dilute 50 or 60 gallons of water.
Copper Carbonate Mixture
1 pound copper carbonate.
40 gallons water.
Mix the copper carbonate with small quantity of water
to make a paste; then dilute with the required amount of
water. For fruit rot of the peach, etc. (Delaware Agr. Exp.
Sta.. Bull. XXIX).
Copper Aoetate
6 ounces copper acetate (diabasic acetate).
50 gallons water.
First make a paste of the copper acetate by adding water
to it: then dilute to the required strength. Use finely
powdered acetate of copper, not the crystalline form. For
the same purpose, and of the same value, as the preceding
formula.






IPLANT D)ISEASES A\t) ADEP'l'S


Copper Sulphate Solution
(Strong Solution)
1 pound copper silphate.
25 gallons water.
.Apply only 1n trees without foliage.
Copper Sulphate Solution
(Weak Solution)
2-4 ounces copper sulphate.
50 gallons water.
For trees ill foliage.
Potassium Sulphide
:3 ounces p)ota.ssiuml sulphide.
10 gallons water.
'Viauable for gooseberry mildews. etc.
Potassium Permanganate
I part potassium peri)manganate.
2 parts soap.
100 parts water.
Recommended ill France for black rot and inildew of the
grape. etc.
Iron Sulphate and Sulphuric Acid
Water (hot). 100 parts.
Iron sulphlte, as much as will dissolve.
Sulphuric acid. I part.
Prepare solution just before using. .dd the acid to the
crystals. and then pour on the water. Valuable for treat-
ment of dormant grape vines affected with antlhraenose, ap-
pliention being made with sponge and brush.
Corrosive Sublimate
(For Potato Scab)
2 ounces corrosive sublimate.
15 gallons water.
Dissolve the corrosive sublimate in 2 gallons of hot water.
Then dilute to 15 gallons, allowing the same to stand 5 or
6 hours. during which time thoroughly agitate the solution
several times. Place the seed potatoes in a sack and inmmerse




DEPARTMENT OF AGRICULTURE


in the solution for 11% hours. Corrosive sublimate is very
poisonous; consequently, care should be taken in handling it,
nor should the treated potatoes be eaten by stock. The solu-
tion should not be made in metallic vessels.

Formalin
(For Potato Scab)
8 ounces formalin (40% solution).
15 gallons water.
Used for the same purpose as corrosive sublimate, but not
poisonous. Immerse the seed potatoes for two hours.


INSECTICIDES
Paris Green-Dry
1 pound Paris green.
20-50 pounds flour.
Mix thoroughly and apply evenly; preferably when dew
is on the plant.
Paris Green-Wet
1 pound Paris green.
I/ pound quicklime.
200 gallons water.
Slake the lime in part of the water, sprinkling in the Paris
green gradually; then add the rest of the water. For the
peach and other tender-leaved plants, use 300 gallons of
water. Keep well stirred while spraying.

Arsenite of Lime
1 pound of white arsenic.
2 pounds of fresh burned lime.
1 gallon of water.
Boil together for 45 minutes and keep in a tight vessel.
Add 1 quart of this to a barrel (50 gallons) of water, for use.
This insecticide has been recommended by a number of
experimental stations, but has not yet been sufficiently tested
at the. Massachusetts Station to receive an endorsement.




P LAX'r DISEASES ANN) PES-14S


Arsenate of Lead
4 ounces arsetnate of soda (50%c strength).
11 ounces acetate of lead.
150 gallons of water.
Put the arsenate of soda in 2 quarts of water in a wooden
pail, and the acetate of lead in 4 quarts of water in another
wooden pail. When both are dissolved, mix with the rest of
the water. Warm water in the pails will hasten the process.
For the elm-leaf beetle, use 25 instead of 150 gallons of water.
Whale Oil Soap
2 pounds potash whale oil soap.
1 gallon hot water.
For winter use only.

Kerosene Emulsion
1/. pound hard soap. shaved fine.
1 gallon water.
2 gallons kerosene.
dissolvee the soap in the water, which should be boiling;
remove from the fire and pour it into the kerosene while hot.
Churn this with a spray pump till it changes to a creamy,
then to a soft butter-like mass. Keep this as a stock, using 1
part in 9 of water for soft-bodied insects. such as plant-lice,
or stronger in certain cases.

Mechanical Emulsion
SA substitute for the last. Made entirely by the pump,
which draws water and kerosene from separate tanks and
mixes them in tlhe desired proportion by a mechanical device.
Several pumps for the purpose are now on the market.

Resin-Lime Mixture

5 pounds pulverized resin.
1 pound concentrated lye.
1 pint fish or other animal oil.
5 gallons water.





DEPARTMENT OF AGRICULTURE


Place the oil, resin and 1 gallon of hot water in an iron
kettle and heat till the resin softens, then add the lye and
stir thoroughly. Now add 4 gallons of hot water and boil
till a little will mix with cold water and give a clear amber-
colored liquid; add water to make up 5 gallons. Keep this
as a stock solution. For use, take 1 gallon of stock solution,
16 gallons water, 3 gallons milk of lime, i pound Paris green.
The object of this preparation is to obtain an adhesive
material which will cause the poison to adhere to smooth
leaves. It has been highly recommended by the New York
State (Geneva) Experiment Station.

Lime, Salt and Sulphur
Oregon formula:
50 pounds unslaked lime.
50 pounds flowers of sulphur.
50 pounds common salt.
Slake the lime in enough water to do it thoroughly, add
the sulphur and boil for an hour qt least, adding water if
necessary. Then add the salt and boil 15 minutes more. Add
water to make 150 gallons, and spray hot through a coarse
nozzle.
Lime, Salt and Sulphur
Marlatt's formula (from Smith):
30 pounds unslaked lime.
30 pounds sulphur.
15 pounds salt.
60 gallons water.
Boil with steam for 4 hours, and apply hot.
Carbolic Acid Emulsion
1 pound hard soap, shaved fine,
1 gallon water.
1 pint crude carbolic acid.
Dissolve the soap in the water, boiling; add the carbolic
acid and churn as for kerosene emulsion. Use 1 part of this
with 30 parts of water.





I' LANTIsEAMES ANI) P'l'S


Hellebore
1 ouniec hellebore.
1., gallon water.
Steel) tile hlellelore in a pint of water and gradually add
the rest of tile water. liellebore may also be dusted over the
plants. either pure or mixed with flour or plaster.
Insect Powder; Pyrethrum
Mix with hall its bulk of flour and keep inl a tight call for
24 hours; then dust over tile plants. )r.
100 grains insert powder.
2 gallons water.
M.ix together. aid spray.



COMBINED FUNGICIDES AND INSECTICIDES

Bordeaux Mixture and Paris Green
4 ounces Paris green.
50 gallons 1Bordeaux mixture.
Bordeaux Mixture and Arsenate of Lead
1 gallon ar senate of lead (made by formula No. 20).
50 gallons Bordeaux mixture.
Bordeaux Mixture and Arsenate of Lime
I1/, quarts arsenate of lime (made by formula No. 19).
50 gallons Bordeaux mixture.

Soap Mixture
(Used for White Fly)
1 bar soap (10-cent size).
3 gallons water.
Apply warm, as it thickens oni cooling.
RIeccniunended for rose mildew. red spider. plant-lice. etc.
Any comiluon laundry soap, particularly tie yellow resin
sollps, dissolved 1 pound of soap to 15 or 20 gallons of water,





DEPARTMENT OF AGRICULTURE


is an efficient application for white fly, red spider, plant-lice,
etc. The addition of 1/ pound of Paris green to each 50 gal-.
Ions of soap solution adds to its efficiency. There is probably
no better formula for white fly than the above.
Equal parts of soap solution and sulphur wash-made by
dissolving 20 pounds of sulphur with 10 pounds of caustic
soda is a most excellent general application.
Sulphur Wash
First mix 20 pounds of flowers of sulphur into a paste
with cold water, then add 10 pounds of pulverized caustic
isoda (989). The dissolving lye will boil and liquefy the
sulphur. Water must be added from time to time to prevent
burning, until a concentrated solution of 20 gallons is obtain-
ed. Two gallons of this is sufficient for 50 gallons of spray,
giving a strength of 2 pounds of sulphur and 1 of lye to 50
gallons of water. An even stronger application can be made
without danger to the foliage. This mixture can also be used
in combination with other insecticides.
The chemical combination of sulphur and lime, known as
bisulphide of lime, is perhaps a better liquid sulphur solution
than the last as a remedy for mites. It may be very cheaply
prepared by boiling together, for an hour or more, in a small
quantity of water, equal parts of flowers of.sulphur and stone
lime. A convenient quantity is prepared by taking 5 pounds
of sulphur and 5 pounds of lime, and boiling in 3 or 4 gallons
of water until the ingredients combine, forming a brownish
liquid. This may be diluted to make 100 gallons of spray.
Almost any of the insecticides with which the sulphur
application may be made will kill the leaf or rust mites, but
the advantage of the sulphur arises from the fact that it
forms an adhering coating on the .leaves, which kills the
young mites coming from the eggs, which are very resistant
to the action of the insecticides and result in the plants being
reinvested unless protected by the sulphur deposit.
For spraying machinery address State Market Bureau.
Jacksonville, Florida.




PLANT DISEASES AND PESTS


ZINC SULPHATE SPRAYS FOR VEGETABLE CROPS
BY O. R. TOWNSEND
Associate Plant Pathologist. Everglades Experiment Station

Abnormal conditions of several crops growing in the
Southern Coastal Plains have been found to he caused by a
deficiency of available zinc in the soils. Experiments have
shown that these abnormalities can be overcome by apply-
ing zinc sulphate to the soil. or by spraying the plants with
a solution of this material. Pecan. tung and citrus trees and
corn have respolled to one or hoth of these methIods of treat-
ment.
More recently, the failure of beans growing on saw-grass
soil in the Florida Everglades has been traced to a lack of
zinc. Such failure has not been observed on tile older soils
of tle Lake Okeechobee region. hut has come to the attention
of the Everglades Experiment Station only on newly cleared
land at some distance from the lake. While zinc sulphate
may lie found useful for vegetable crops throughout the
state, its value has been demonstrated only for the area of
peat soil in the Everglades lying more than two miles from
the shores of Lake Okeechobee.
The symptoms of zinc deficiency in beans are a yellowing
and withering of the foliage. followed inl tle most severe
cases by tle death of the plant. Beans will grow normally
on zinc-deficient soil for three or four weeks. but after that
period the plants cease to grow. become pale. and the leaves
develop longitudinal streaks of dead tissue. The principal
veins remain green longer than the rest of the leaf. In the
final stages of the disease entire branches of the plant col-
lapse and wither.
Zinc deficiency in beans differs from man ganese defici-
ency wllich occurs chiefly on burned peat or on marl soils.
Manganese deficiency develops earlier in the growth of the
plant than zinc deficiency. and is characterized at first by. a
mottled yellowing. In the later stages of manganese idefici-
ency bean leaves have a brilliant yellow color and are marked
by rows of black dots along the principal veins. Further-





DEPARTMENT OF AGRICULTURE


more, beans affected by manganese deficiency show response
to treatment in 30 hours, while four or five days are required
for definite response to be seen in plants treated for zinc
deficiency.
Copper deficiency which occurs in raw saw-grass soils
causes symptoms on beans which are not readily distinguish-
ed from those of zinc deficiency. Copper deficiency seems to
be of a more transitory nature than either zinc or manganese
deficiencies.
Zinc sulphate may be dissolved in water and sprayed on
plants with knapsack sprayers or power driven machines. In
the first tests five pounds of 89 per cent zinc sulphate were
dissolved in 50 gallons of water. This was adequate to cor-
rect the deficiency in beans and did not burn the foliage.
Subsequent experience of growers has shown that two pounds
of 89 per cent zinc sulphate in 50 gallons of water is fully
effective. The tests which have been conducted with vege-
table crops have shown no need to add lime to the spray. Zinc
sulphate, may be added to either Bordeaux mixture or man-
ganese sulphate solutions if these sprays are being used. How-
ever, the effectiveness of the zinc or manganese sprays prob-
ably is greater when they are not mixed with other materials.
Some recommended formulas are given below:
2 pounds 89% zinc sulphate
50 gallons water
2 pounds 89% zinc sulphate
4 pounds 83% manganese sulphate
50 gallons water
2 pounds 89% zinc sulphate
50 gallons 2-3-50 Bordeaux mixture
The proper time to apply zinc sulphate sprays is before
the crop shows the need for treatment. This can be done if
previous experience has shown the land to be deficient in zinc.
It is best to make the application before the crop is three
weeks old. Recovery of diseased plants has been observed
when they were five weeks old before the spray was applied.
Usually a second application will not be needed.
Plants which have been very sickly and stunted have been
observed to recover and show a luxuriant growth within two





I' lANS'l DllEASES ANDI PEs'I's


to three weeks from the time of application. Beans which
responl in this manner will yi'ld a normal erop, whereas
Vitlihout sprayingi the crop may be a failure.
'Cabbage. peas and potatoes also have been observed to
fail on zinc deficiency saw-grass soil. and these plants also
respond to zine sprays. Ill general tilte symptoms are similar
to those onl hceas. The plants grow normally tor two or three
weeks, but later show a loss of color and sudden blighting of
portions of leaves, or wilting of the entire plant. When peas
and cablbae are sprayed a soap spreader should he added to
the spray.
Zinc sulphate can be obtained from dealers in agricultural
supplies. Its cost is approximately tle sanne as that of blue-
stlone and manganese sulphate. There are several grades of
zxin sulphate ,n the market. lThes' differ in the lamnoutnt of
water which they carry in combination with the zinc. The
zinc silphate with Il te least water is a pure white salt. It
contains tilhe (equivalent of :1(i per cent metallic xince. or 89
per ce('t water-free zinc suiplliate.

MANGANESE SULPHATE SPRAYS FOR
VEGETABLE CROPS
BY O. R. TOWNSEND
Associate Plant Pathologist. Everglades Experiment Station

The yellowing of vegetable crops growing on slightly acid
to alkaline soils is frequently due to a deficiency of available
manganese. This element. which seems to be essential for
the production of chlorophyll in plants, is nearly inisoluble
ill soils having pH values from 6.2 to 8.0. Too much lime in
a soil will create such a condition: it exists naturally in marl
and limestone soils. and may occur also as the result of burn-
ing peat or muck soils. Where the amount of manganese is
naturally low. this partial insolubility will create i deficiency
in the amount available for lte growth of plants.
Experiments have shown three ways in which manalllese
deficiency may be overcome. These are by applying maln-
ganese to the soil, by making tile soil more neidt or by spray.





DEPARTMENT OF AGRICULTURE


ing the plants with a solution of manganese sulphate. Addi-
tions of manganese sulphate with the fertilizer produce a
concentration of available manganese sufficient for the growth
of one or two crops on neutral or alkaline soils. Usually 25
to 50 pounds of manganese sulphate per acre per year will
maintain production on peat soils which are neutral or alka-
line in reaction. Somewhat more than this is required where
the peat soils show large amounts of brown ash.
It is possible to increase the availability of the manganese
in a soil by making it more acid. This can be done by the
application of sulphur. The amount of sulphur needed will
depend upon the type of soil and its alkalinity. For burned
peat soils in the Everglades the use of 50 to 100 pounds of
sulphur per acre is sufficient, except where the soil contains
large amounts of ash.
Neither of these methods is more effective than spraying
the plants with manganese sulphate solutions. Experiments
with beans on burned peat soils in the Everglades have shown
that the yellowing due to a deficiency of available manganese
can be prevented by the application of manganese sulphate
solutions to the foliage of affected plants. Beans which have
become very yellow will recover and produce a normal crop
after being sprayed with manganese solutions. Usually one
application is sufficient, but two or three applications will
be helpful where the soil is quite alkaline.
Spraying with manganese is more economical in material
than the use of manganese or sulphur in the fertilizers be-
cause less manganese is needed. It has been found that 10
pounds of manganese sulphate sprayed on an acre of beans
is as effective as 25 to 50 pounds applied with the fertilizer.
Furthermore, it is not necessary to apply the spray until the
need is shown by the plants, while soil treatments must be
made before the need is shown. Spraying is more effective
on the most alkaline soils where manganese applied to the
soil is rendered insoluble in a short time.
Yellowing of the foliage alone is not always a sign that
manganese is needed. It may occur from a variety of other
causes of which root-knot, root-rot, a flooded soil, and defici-





P' LANT DISEASEs NI) ANEsDrS


encies of copper or zinc are common. When the yellowed
plants are growing on burned peat or marl soils one may be
practically certain that a deficiency of manganese exists.
Bean plants growing on such soil will be green for two or
three weeks and then begin to show a yellow mottling he-
tween the veins of the leaf. In the later and more severe
stages of the disease. the bean leaves become golden yellow,
and often have small dark spots along tlie veins. I't inlately
the plaits die. If there is aniy doubt as to the eause of the
yellowing a few plants should he sprayed with a manganese
solution. The normal green color will begin to return to
sprayed foliage within 30 to 48 hours if there has been a
deficiency of manganese.
The usual procedure for spraying is to dissolve four pounds
of manganese sulphate in ;5 gallons of water, and to apply
this solution with knapsack sprayers. Fifty gallons of the
solution is enough for an application on one to one and a half
acres of vegetable crops. For crops such as beans no spreader
need be mixed with the spray. When peas or cabbage are
to be sprayed the use of a soap spreader is advised. Lime
may lie added to the solution if there is any tendency to burn
the foliage with the manganese spray. This seldom happens.
however, and the addition of lime is not recommended for
spraying beans, peas. potatoes, and tomatoes.
When it is desirable to apply other sprays, the manganese
may be mixed with themI. Some recomniende( d miixtures are
given below:
4 pounds 83% manganese sulphate
50 gallons water
4 pounds 83% manganese sulphate
2 pounds 89% zinc sulphate
50 gallons water
4 pounds 83% manganese sulphate
50 gallons 2-3-50 Bordeaux mixture
Manganese sulphate is available at growers' supply houses.
where it usually may be had in two grades. ()ne grade is a
granular yellow material suitable for use in fertilizers. It
contains 63 per cent of manganese stulphate. The fine gray
powder used for mixing manganese sprays contains 80-83
per cent manganese suliphate and is readily soluble in water.





DEPARTMENT OF AGRICULTURE


Plant Diseases and Pests
Part Two

GENERAL GARDEN INSECTS AND PESTS
BY J. R. WATSON
Entomologist. University. Oainesville. Florida

There are a number of insects that attack practically all
garden crops and could not well be included under only one
of them. They are treated here.
Heat Treatment for Seeds
A temperature of from 120 to 130 degrees Fahrenheit, if
maintained for a half hour, is fatal to practically all insect life.
If a bag of seed can be placed in an oven, with a dish of water
to supply moisture, and kept at a temperature of 120 to 130
degrees F. for from 20 to 30 minutes, insects in it will be
killed and the germinating power of the seeds will remain
unimpaired.
Scavengers
Many insects breed in injured and rotting fruits and vege-
tables. The most common of these are sap beetles (Nitidu-
lidae) and pomace flies.
Sap beetles are small, with wings too short to cover the
abdomen. They quickly invade an orange that has split from
any cause but do not, as is often supposed, cause the splitting.
Pomace flies are small two-winged flies that lay their eggs
in rotting fruits and vegetables. These hatch into maggots
that develop in the rotting material. They do not attack
sound fruit.
Grasshoppers
These insects are particularly annoying on early fall crops.
At that time native vegetation is becoming dry and unattrac-
tive and the grasshoppers, many of which are then in the late




ILANT DISEASES AND PESTS


nyniphal or the adult stages and consume more vegetation than
the very young, flock to the farmers' crops.

There are many genera and species of grasshoppers. One
of the most common and troublesome is the red-legged grass-
hopper. This is one of the smaller kinds but makes up in num-
bers what it lacks in size. On flatwoods and muck lands the
lubberly locust is often troublesome. This is the largest grass-
hopper in Florida. The young are black with reddish mark-
ings. There are two color-forms of the adults. Some are of
a striking yellow color and others are almost as black as the
larvae. These grasshoppers have very short wings and are
incapable of flight.

Grasshoppers lay their eggs in the ground in waste places
at a depth of 1 or 2 inches. Cultivation will destroy the eggs
when they are laid in cultivated land; consequently it is in
small fields surrounded by waste land that grasshoppers are
most troublesome. As the proportion of land under cultiva-
tion in a neighborhood increases, these insects become less
of a pest.

Control.-Birds, including domestic towls, especially tur-
keys, are very fond of grasshoppers. The general farmer
should keep a flock of turkeys, for their insecticidal value if
for no other reason. They would, of course, he out of place
on a truck farm or town lot. The lubberly locust is, however.
distasteful to all birds and will not be eaten by them.

The cheapest and most effective method of dealing with
grasshoppers is by means of poisoned baits, of which the
so-called "Kansas formula" is the best. It has proven very
satisfactory wherever tried. It is

Bran or shorts ..................... ................. 25 pounds
Paris green or white arsenic (oxide).... 1 pound
W ater ....................................................... 2',, gallons
Lemons, oranges, or cantaloupes ........ 3 or 4
Syrup .................... .... ......................... 2 quarts
Cottonseed meal may to advantage be substituted for half
of the bran.





DEPARTMENT OF AGRICULTURE


The Paris green and bran should be thoroughly mixed
(dry). Lead arsenate should not be used. It does not work
as well. The lemons should be thoroughly grated or chopped
very fine, rind, pulp, and juice, and added to the water.
Moisten the bran with the water until the whole is damp, not
sloppy, so that when sown broadcast over the land it will fall
in small flakes. Last of all add the syrup and thoroughly
knead it into the bran. This should be sown in the early
morning, about sunrise or before. Grasshoppers do not eat
at night, and consequently have a good appetite in the early
morning, and the bait should be on hand for their breakfast.
If sown in small flakes over the field there will be no like-
lihood of chickens or other domestic animals picking it up,
nor will wild birds be endangered. Ordinarily there will be
no danger to chickens or other fowls eating the dead grass-
hoppers as the fowls will not get enough arsenic in this way
to harm them.
Mole Crickets
These are flat, like other crickets. Their front legs are
greatly enlarged and fitted for burrowing (Fig. 56). They
live deep in the ground during the
day-time, coming out at night to
*feed.. They are very destructive to
vegetation, particularly in gardens
and seed beds. They make, just
beneath the surface of the ground,
runways resembling those of moles
but very much smaller.
There are at least two native
species of mole-crickets that are
somewhat destructive in truck
patches, especially in low ground
where there is considerable vege-
table mold. In addition, thke West
S I ndian mole-cricket or changea"
(Fig. 57) is becoming very trouble-
i'G some in some sections of the State.
PIO. 5.--Native molp-
cricet. Natur size. Control.-Sulphur placed in the
(Original. )





IPLAN'T DISEASES AND) PE.sTrs


seed drill is said to act as a deterrent. Mole-crickets may be
kept out of seed beds by a guaze floor. At the time the seed
bed is made. dig out the earth to thet depth of a foot or so and
place ill the bottom a layer of gal-
vanized or copper wire mosquito
netting. It should come up at the
sides and project a couple ofi diches
above the ground.
Plants set out ill the field may
be protected by handing tliiem.
For this purpose mnelt off tihe tops
and bottollms of tin canlli alid acl pie
the cylinder over eachI plant. sink-
ing it into the earth to some dl'pti.
Instead of tlie till can'. tarr~'d
paper may be used.
Mole-crickets may be poisoned
by a mIixture of coltton-seed meal. FIG. 57.--hangs." or
bran. Paris green and syrup ias ad- re Ind an mole
cricket Natural size.
vised for grass hoppers. Better re- ,porto Rico Exp. St.1
suits have been obtained by shubtituting commercial ,, eg mash
for the bran.
Like other insects which live in the ground. mole-crickets
Imay be poisoind by carbon hisulphide. Sink into the infested
garden several holes to the .square yard. These can be made
with a cane. if the soil is a bit moist. and should go down to
a depth of one foot. Pour into each hole an ounce of tlie
liquid. and quickly cover the hole. ('are must be taken to
keep the liquid away from the plants or they also will be
killed: also keep the liquid away from fire or lights as it is
very inflammable.

Another and cheaper liquid which can he utsed inl the same
manner is a solution of sodium cyanide in water, about an
ounce to two gallons of water. ('aleiun cyanide flakes or
granules can also be used.
If the garden is known to be infested at planting time it
should be treated before it is planted. For this purpose





DEPARTMENT OF AGRICULTURE


scatter calcium cyanide in the furrow or treat it with sodium
cyanide and ammonium sulphate as advised for root-knot.
Or the garden may be treated as follows: Plow it and level
it off smooth and compact the surface with a roller or the
back of a shovel. If the soil is dry, first wet it. Leave it ovei
night. The following morning go out with a solution of
cyanide in water, or carbon bisulphide. The presence of the
mole-crickets will be revealed by their galleries and by little
piles of soil freshly thrown up. Wherever such signs are seen
punch a hole to a depth of a few inches and pour into it a fluid
ounce or two of the sodium cyanide solution or a tablespoon-
ful of carbon bisulphide. Repeat the operation every night
until no more signs of their presence are seen.
To reduce the number of mole-crickets in badly infested
ground, plow deeply several times in the spring, from March
to June. when they are breeding most actively. Allow
chickens, and especially turkeys, to follow the plow for they
are very fond of these insects. Pasture hogs on the field
when possible. When mole-crickets are flying during March
or April (they do not fly much at other seasons) great num-
bers can be caught in light traps. Suspend a lantern in the
field and place under it a pan of water on the surface of which
there is a thin layer of kerosene.
Moles
Moles are a nuisance in lawns and gardens because of the
extensive tunnels they make beneath the surface of the soil.
In making these tunnels they break off the roots of the plants
and cause the soil over the tunnels to dry out. Contrary to
common opinion, they do not feed extensively on vegetation
but are mostly insectivorous in their diet. They are fond of
"white grubs" which are the larvae of May-beetles or June-
bugs. These white grubs are most abundant on land that has
been allowed to grow up in grass during the summer. The
first step in fighting moles is to get rid of the white grubs.
This can be done by raising some cover crop such as cowpeas.
velvet beans or peanuts on the land to keep down the grass
during the summer, and also by turning pigs in on the land





PLANT DISEASES AND PESTS


for a few weeks before the garden is plowed. (See white
grubs under potatoes. page 128. for further suggestions.)
Although, by eating the white grubs, moles perform a good
service to the grower, like some other troubles, the remedy is
often worse than the disease.
Oontrol.-Moles may be discouraged from burrowingi in
the garden by tranlping the soil solidly into their runways
or crowding a brick or a stone into it where it enters the
garden froin the outside, making sure. of course, that the
mole is not ill the garden when this is done. The presence of
the mole is best detected in the early morning by tlhe ridges of
fresh dirt or the movement of the soil as he forces his way
through it. In the latter case the mole can at onc e be dug out
and either killed or. better. carried off to some pasture
or waste land where his activities will be beneficial rather
than harmful.
Moles make two types of tunnels. One is tlie feeding
tunnel which is but a few inches below the ,uirface of the
ground. The other is larger and located much deeper, a
foot or more. This is the main highway for the moles in
going from one end of their range to the other. Moles may
be trapped by uncovering this main roadway alnd placing in
the breach a mole trap. several of which are on the market.
In sandy soil these will often spring out of the soil when
sprung by the mole. This can be largely prevented by tying
a weight to the trap. Nine parts of finely ground beef steak
thoroughly mixed with one part of a rat poison containing,
phosphorus has been used to control moles.

Mice
The prevalent idea that moles feed largely on tlhe roots
of plants arises from the fact that their runwayy. are com-
monly used by field mice which do the damage. Stopping
up the runways will discourage the mice as well as the moles.
In the kitchen garlde both moles and mice iay often be
drowned out by turning the garden hose into tile runway.
The mice may be poisoned by putting in the runways some





DEPARTMENT OF AGRICULTURE


corn that has been soaked in arsenic, Paris green or alkaloid
strychnine.
These mice are known as field mice or white-footed mice,
belonging to the Peromyso polionotus group. They are
small mice about five inches long, white underneath and gray
or brownish gray above. They live in burrows in the ground,
the entrance of the burrow being in an open place with a
small mound of soil thrown up in front of it. These burrows
are generally less than two feet deep and about three and a
half feet long, the burrow turning up at the back and the
end being just under the surface of the soil so that the mice
often break through at that point when one is digging them
out. These mice are very prolific, young being found through-
out the year. The litters vary in size from two to six. These
mice are capable of producing a second litter in less than 25
days after the first is born, so that if food conditions are
favorable and natural enemies lacking a very large population
may be produced in a short time. Hawks, owls, skunks, and
snakes are natural enemies of these mice and should be pro-
teeted. It is easier for the farmer to protect his chickens from
these predators than to control the mice in his fields.
The mice are most abundant in old fields so that the great-
est trouble is likely to occur on old ground or in new ground
adjacent to old fields. They cause damage by digging up
newly planted seed. In cage tests it was found that on the
average a mouse could eat about two dozen seeds in a night
and in newly planted fields seeds which the mice dug up were
found stored in their burrows. Thus, during the week or 10
days that the seeds are in danger, less than a dozen mice per
acre can ruin a stand of melons or corn.
A poison bait was found to give the best control. Such a
bait may be prepared as follows:
Mix together one ounce of powdered alkaloid strychnine
and one ounce of baking soda. Sift this over eight to 10
quarts of rolled oats. stirring well to get a uniform distribu-
tion throughout the mixture. Warm the oats in an oven,





PISANT D)ISEASES AND PESTS


taking care that they are not scorched. Sprinkle hot beef fat
over the oats at the rate of six tablespoonfuls per quart of
oats and stir until all of the particles of oats are thoroughly
covered. It is best to make this bait up on the same day it is
to be used. In distributing it in the field a teaspoonful should
be placed at about 20 foot intervals about two days before
planting. The above quantity should treat alout four acres.

It is of the greatest importance in making, this hail to use
only the alkaloid strychnine. Local (drr.gists very often do
not carry this and the strychnine sulphate that they do carry
in stock is not nearly so effective as the other. number of
growers who ha\e used the stry'hnine slfate for years
round that they got far better results when they changed to
the alkaloid str'yehnine. Therefore. growers should estimate
the amount of alkaloid stryehlnine they will need aind have it
ordered so that it will be on hand at planting time. This may
save rephlanting and enable tie grower to get melons on the
market a week earlier, which i, al important factor in Florida.
It is the practice of some growers to soak their seed he-
fore planting to hasten germination From the standpoint
of mouse control this is a desirable practice as it shortens the
time during which damagee from mice is likely to occur.

Salamanders
The so-called "salainander" of Florida is a ground squir-
rel much more nearly related io the pocket gopher of the.
West than to the true salamander, which is a frog-like ani-
mial with a tail. If they invade lte garden they may be
poisoned by the bait given above for miice or their Iu1.rrows
opened and small steel traps set in their runways.

Gophers
'The so-ealled "gopher" of Florida is a I.urro wing turtle.
These gopher turtles live in deep burrows which are easily
located because of their large size ld tile mounds of subsoil
thrown up at the entrance. IThe animals feed on the melon
vines for tile most part. early in tile morning or late inl tile





DEPARTMENT OF AGRICULTURE


afternoon, staying in their burrows most of the day. The
following method of control can be used.
Break up corn cobs into three or four inch lengths and
soak them in carbon bisulphide. Throw the pieces down the
burrow. They are heavy enough to roll down quite a distance
so that the fumes are given off near the "gopher". As soon
as the cobs have been thrown into the burrow close the en-
trance by packing the soil tightly about it. A few days later
the results should be checked. If the gopher has emerged a
larger dose should be administered. After a little experience
a grower should be able to gauge the amount of carbon bisul-
phide to use.
Ants
One of the nuisances with which the gardeners and truck-
ers have to contend is ants. The amount of damage they will
do depends to a large extent on the species. Following are
mentioned some of the ways in which they are annoying in a
garden.

They eat off growing plants, such as cabbage. Most species
feed to a limited extent only on growing vegetables, but many
species seem to object to the presence of vegetation about
their nests. This is particularly true of the large yellow
agricultural ants which will keep a space many feet in diameter
about their nests absolutely free from vegetation. The leaf-
cutting ants which are found in the southern part of the
State, cut off and remove to their nests a large number of
leaves. They do not use these directly for food, but to grow
a kind of fungus of which they are particularly fond. They
were the first mushroom growers. They are particularly an-
noying to citrus trees in the tropics where they abound.
One of the most annoying habits of ants is that of carry-
ing away seeds from seed beds. They are particularly fond
of lettuce and romaine seed. They use the seeds for food
and will begin to carry them to their nests as soon as planted
and will continue their pernicious activities all through the
germination period and until the young seedlings have used





P LANi'T I)ISEXSES AND) IPES'I'S


iup all of the material in the seeds. Ants often cover up
plants by building mounds over them.
Ants are very fond of the honeydew given off by aphids.
some jassids, mealy bugs and other scale insects. For the
sake of this substance many kinds will tend those insects.
sometimes driving away their enemies aind more commonly
carrying those pests from one plant to another. (See gar-
den aphid under cabbage plant-lice, page 83.)
Ants in the truck patch and garden. especially those that
sting. are somewhat of an annoyance to workers.
Control.- Ants are best destroyed in their nests. For this
purpose carbon bisulphide can he used but sodium cyanide is
cheaper. Dissolve the cyanide in water, an ounce to two quarts
of water. With a cane or sharp stick punch a hole to the
depth of a foot or more in the center of the hill and pour into
it a few ounces of the solution. The dosage to be given as
well as the depth of the hole will depend upon the size and
depth of the nest. As soon as the liquid has soaked away.
cover up tile hole with dirt and tramp it solid. The gas given
off will penetrate the galleries of the nest and kill most of
the ants and their young. It is best to do this in tile early
morning when most of the ants are "at home." All of the
nests within .10 or 60 feet of the seed bed should be treated.
As recorded under the head of fumigationn, cyanide is one of
the most powerful poisons known, either when inhaled or
swallowed. It should also be kept out of open sores. Some
ants will probably escape the first treatment. These will.
however, lose all interest in the seed bed and will go slowly
about, cleaning the dead ants out of the nest. Their slow
and languid motions are in sharp contrast to their feverish
activity of the previous day. The survivors will probably.
in the course of a few days. start small new nests in the
vicinity. These in turn may be treated.
The following is from .J. R. Watson. Entomologist and
Head of Department, University of Florida. in reply to a
letter received from Jacksonville, Fla.. June. 1938:
"I regard to trouble with ants: For large nests and deep




DEPARTMENT OF AGRICULTURE


ones. carbon bisulphide is about the best thing to use. Just
punch a hole iin the middle of the nest and pour down it about
an ounce or so of carbon bisulphide, according to the size of
the nest. and by stepping on it compact the soil so as to re-
tain the gas. Carbon bisulphide will penetrate the burrows
of the nest better than any other common material.
"Judging from the description, however, you probably have
the so-called 'carpenter' ants. These ordinarily do not nest
out in the yard but in a piece of rotten wood, or in such things
as bamboo you mention, particularly if there is a lot of trash
in the clump as there is apt to be. They may, however, be
nesting in some rotting timber in the building. If you find
they are issuing from some hole in the building, pour a little
carbon bisulphide down this hole, remembering of course that
you have a fire risk and you must keep all fire, including
pipes and cigarettes, away as long as there is any odor re-
maining.
"I note you have had no results with arsenate of soda in
sugar and water. Perhaps you have been making this too
strong. If you use too much arsenic the ants will not touch
it. Follow the directions given in the press bulletin.
"Mr. C. F. Mershon, 2'23 East Ashley Street. of your city.
is agent for a very good bait for ants. This contains thalium
as the poisonous principle. Thalinm is very powerful stuff
and you must not use this bait where children or other care-
less people might get hold of it.
"It is not probable that the ants come into your place from
your neighbors property unless your neighbors are very close,
indeed. Fifty or 100 feet is about as far as these ants will
ordinarily go. One thing is certain, where you have these
ants around you you will have no termites as ants are mortal
enemies of termites."
White-ringed Beetle
The following is from Arthur C. Brown, Grove Inspector
of State Plant Board, in reply to a letter received from Rich-
mond, Va.. June, 1938:





P LANT DI*-HASEASI, AND) PESTS


"Tl'liis inlsert wits first noted doilli considerable( dama(11 ge to
ellltivatedl aiind wild plant 1s a little over a year iago. It 'was
reported that it was found l i a portionl of Ok(aloosa. amid Wal-
ton Counmtie%. Florida. anmid in the sotiheri portion of ('oving-
toin Conity. A.llal)lna. Thel town of Floraili. A.lbamia is about
thle centei'r of tle F.loridi-A\lla iii infested area. The (ilamage
is ilcaused y tlV Ilie larvae eatill tlie' roots of 'everial of our cul-
tivated crops. as well as wild pla nts. Thle adults eimertge from
tlie gronmll dulriill 1i11 s1111iiimnr il large iinlmbers alnd. while
the liy eanl s elline dIniimIa re to the I'flilag of plants in their ea'.tillr .
it is not as -treai s t ail lt bruised hy tlli lairvite attaI king tihe
roots.

"The litrean of Elnioiologl y ald l manh Q(larainttile. lilited
States )Dpartit i ill of Ac.\ riilllt rel. midlertook to e<'ar.y oon some
control Ime.asures ill eooperaition witi tlih States of Florida
iaimd AlabaiiNm ill t ie slilllintr of 193:7. I 1isp.l)tion so far has
diselos-ed their preell'ce of this p let in Pe.,isa'ola. in several
coullnties ill tihe soiitheir ii par of Mississippi. anll in tlie vicinty
of 'New Orleans. How it was introdhled int tihe it'nited States
no one is pilepared to s tate. How imulie damiilage it will cause
to our cultivated crops is another question that remains to be
answered. At present it would appear that it maiy be a major
pest of cornl. .ottoll. pinu1i eetli fits an.d velvet beans. The
roverliineiit is iundelrtakiln to do considerable research work
in the vicinity of Floraa. where they have established a lab-
oratory under thlie direction of Mr. II. ('. Youmi. They also
have a fielId control office at Floraila. of which Mr. I...l. Pladlget
is in halmrge. The main office is miler tlie direction of T. M{.
('orliss. Ios 94i.S9. (;ulflport. Mississippi.
"-More detailed information as to Itlie host list m d the
possible ecoloillie importance of this pest should be secured
from Mr. I'orliss or from his liiet. I)r. Lee A. Stir chii. Chief,
Bureau of Entomology and Plant quarantinee. U'iiitd Stiate.s
Departlmenlt of Agrietllt ure. Washington. 1). ('."

Root-Knot (Heterodera Mariana)
(See Page 16:11





DEPARTMENT OF AGRICULTURE


Other General Pests
The following named pests attack a large number of vege-
tables and could have been treated appropriately under this
general heading. They are: Fall army worm or grass worm
(see under corn, page 97); red spiders (see under peas, page
121); garden aphid (see under cabbage. page 83); and cut-
worms (see under cabbage, page 75).

BEANS

Bean Leaf-Hopper (Empoasca fabae Harr.)
Several species of jassids severely attack snap beans, espe-
cially those planted early in the fall. Their ravages are ofter
so severe as to discourage the planting of beans at that season.
Jassids obtain their food by sucking the juices of plants.
If the insects attack in sufficient numbers the plants will
become stunted in growth, fail to bear well. turn yellow and
finally die.
Several species are concerned in this injury. The most
abundant is Empoasca fabae or bean leaf-hopper. This is
also called the potato leaf-hopper in the North because it is
there especially injurious to potatoes. It is a light green
insect, 1/ of an inch long. Under a lens the eyes of the living
insect are white but they quickly turn brown after death.
The bug lives on a variety of plants but is partial to cowpeas
and beans. There are many generations a year.
Control.-Bordeaux applied to beans has a distinct ten-
dency to delay the development of leaf-hoppers and if put on
before the leaf-hoppers become abundant it will usually pre-
vent an infestation. It seems that leaf-hoppers are very
sensitive to copper and the plants absorb enough copper
through the leaves to slowly poison leaf-hoppers. Once they
become abundant this, of course, is too slow.
The best control measure for leaf-hoppers is pyretlrum
in sulfur as a carrier. This enables the farmers to control
downy mildew at the same time they control the leaf-hoppers.







It is very important that one raising beans in the fall should
keep a belt several rodls wide entirely around the bean field
clear of all herbaceous vegetation. This can be done by either
plowing the strip and giving it frequent cultivation or cutting
the vegetation off and burning it before the beans come up.
This belt around the field in which there is no vegetation is
very effective in checking the migration of the hoppers from
the silrroltlndiir \egetation.

On the lower last Coast the bean jassid is more injurious
to tlie winter and;il early sprin.ur crops of leans.


Three-Cornered Hopper (Stictocephala festina)
In addliion to i he smaller leaf-holpper, Empoasca fabae,
beans are ciommtonly infested with a much larger one. This
is yellowisli.reen ini color. about a quarter of an inch long
and half as wide. As viewed from above, its outline is that
ofa a tlolg tiriairle. This and its hlahit of feeding on a falfa
have resulted in its being known in the West as the "three-
cornered alfalfa hopper." It is also a pest of tomatoes,
watermelon,;. and cowpeas in Florida. We have also found it
common on hickory. oak. goldenrod. and summer haw
(Viburnum). Control measures would be the same as for
tie smaller species.

Bean Leaf-Roller (Eudamus proteus)
Another inec't which is very troublesome to the early fall-
planted crop is a caterpillar which rolls up the edges of the
leaves after euttingr slits in them. From these shelters tile
caterpillars range over the leaves which are often so badly
eaten that no pods can be formed.
The caterpillar l Fig. .iS). which grows to an inch in length,
is a light greeniish-yellow. velvety insect. The brownish-
yellow head is attached by a neck which is much narrower
than usual in caterpillars so that there is a marked constric-
tion between the head and thorax.


PLANT DISEASE%% AND, I's'r






68 DEPARTMENT OF AGRICULTURE







FIG. S8.-Becn leaf-roller: Larva. Much enlarged.
,Orlginal.1
In the summer the larva will complete its growth il 14
days, but in October and November, 30 or more days are re-
quired. The larva then forms the prpa on the plants and in
6 days the bluish butterfly emerges. The insect belongs to
the group of butterflies known as "skippers." doubtless be-
cause of their habit of darting quickly from plant to plant
in search of nectar or a place for an egg. The eggs are de-
posited on beans and other legumes. especially beggarweed,
and hatch in 4 days in summer. This group of butterflies
when at rest. hold their wings at an angle of about 45 degrees
instead of horizontal or perpendicular as do other butterflies.
This species may be distinguished from other skippers by its
larger size. 2 inches across the outstretched wings, and by
the prolongations ("tails") of the hind wings.
The insects are scarce in the spring and early suImmer so
that early beans are not troubled. But by the first of Sep-
tember the butterflies are abundant and beans become heavily
infested.
Control.-The insect can readily be killed by spraying with
lead arsenate. However, beans are easily injured by arsenicals
so not over 12 ounces of the powdered, or a pound and a half
of the paste. form of lead arsenate should be used to 50 gallons
of water, and to this should be added. before using, a pound
of hydrated lime or the milk obtained from slaking 2 pounds
of quick lime in water. However, it is cheaper to dust beans
for this pest.-one part of lead arsenate to 10'1 hydrated
lime. or 5 pounds of lead arsenate can he added to the pyre-
thrum-sulphur dust.

Bean-Weevil (Bruchus obtectus)
There are two or three species of weevils that infest heans.
The most common is Bruchus obtectus (Fig. 59). The others





I'I.N'Tr )ISEASEs ANDI PENTS


IrC 11 e orl, Einllool (oiln opens and will be treated under that
Ihealdin. Th' ravages of tlis insect on dried beans are very
conspicilus: inl facit, if lnot checked. it will entirely destroy
.seed healis. They also daimlagre tliap beans. The ilnfested Ilids
showl wart-like swellings where the female ptmuntures then
tII lay e(.gs inl tie elvity of tio e )pod. She Inaw\s out I narrow
slit iand tihen inserts her ovipositor inl the hole and lays the
,-*y. These "s eekled" Ilpd shioull inot be confused with
tho.Pe hlavinil. spots caused by the
fIigilis. Colletotrichum. Tlimose s)ots
causel liv I thi rfigiis art simnken iin-
%tead of elevated and attain a i1imcih
lari.er sixci. Thie ei., hatches in from l
1 to i:1 er ks, n.corldilt t to the pre-
v'iiling teimpl)eratulre. into 1 am tll.
worim-like larva. This, reillires from
11 clawr to, 6 wic..k. ;t .o I,.'oIi full ro s-wawU iBrohus
obtAtist : a. Adlt beele. much
yro'wn .iliii thlien cllill .'s into the enl'agd b. Iat.urtd bean.
IProm U. S. Sur. ofl net.p
pill1pl. F'roln 5 to I days in l itri the
adull emiervies. 'T'his i.s aii ashyi black beetle about a tenth of
an ilinch loI.im wil l hard wilni-'asHs ad solewihat flattened
habody.
Nothing rlj (lie d one to proltet tile beimis in the field from
the ravages ,of this insect. The best method of control is to
plant clean eed iin a field that ha% not recently lprmlduced a
crop of co\wpeas ofr heans. Breeding ill dried beans can be
prevented by keeping tlhe beans iln colhi storage (32 to :34
degrees F. for two months or more. or they may be fumlli-
giated as recommended for stored seeds.
LeUser Corn Stalk-Borer (lasmopalpus lignosellus Zell.)
This insect is injuirious to corn in the states farther north:
inl Florida it ,does more (IHIIIamge to cowlpes and beans, although
it is injulrious to corn. Next to the bean-ja.sid it is tie most
injurious iInsect oni fall-planted beans. It often destroys almost
the entire stand if control measures are not adopted. The
insect is a bluiish.-green caterpillar (Fig. 60. d) which bores
into tile stem at tie surface of the ground and tlunnmels up





DEPARTMENT OF AGRICULTURE


C T


FIO. 60.-Leser corn stalk-borer (nasmopelpus lignoselusl:
a. Mole moth; b, wing of female moth: C. moth. showing the
resting position of the wings; d. caterpillar; f. pupa. About
three time natural sie. (Prom U. 8. Bur. of Ent.)

and down in it, causing the young plant to wilt and die quickly.
If the cowpea-plant gets a good start before it is attacked it
is not easily killed and may produce some pods, so that the
damage is not as noticeable, but a bean is usually killed out-
right. The full-grown caterpillar is about a half-inch long.
It is quite smooth; i. e., it is not noticeably hairy. There is
a large brown spot on the back of each segment (joint). The
head is brown and hard and the first joint of the thorax is
black. The adult is a small, brownish moth with cream-colored
markings (Fig. 60, a). It belongs to the same family as
Crambus (see root webworms under corn, page 98) and rolls
its wings about its abdomen in the same manner (Fig. 60, c'-.

The female lays her eggs on the stem near the surface of
the soil and the caterpillar feeds on the surface of the roots
until about half-grown, when it bores into the stem.

Control.-The caterpillars, working inside of the stems, are
safe from any poison that could be applied to the crop. The
young on the roots are also safe. The only means of pre-
venting their spread through a field is to pull up and destroy
all infested plants. Rotation of crops should be practiced.






PLANT DISEASES AND ,Es'l's


Beans should not he planted on land that has just grown
beans. peInuts. cowpeas, turnips or corn. as they are all host
plants.
Other Bean Pests
Other insect-pests attacking beans are: Root-knot nema-
tode (see under general garden pests, page 65) ; cutworms
(see under eabhbae. page 75): corn ear-worm (see under
corn. page !92). sometimes mines tile pods: cabbage looper
fsee under cabbage. page 78i. sometimes cats the leaves;
'.owpea pod-weevil (see under cowpeas. page 102): grass-
hoppers isee under general garden pests, page 54' are trouble-
some in the fall: pumpIkin hbug (see under eowpeas, page 103)
and other plant-lhugs (see under potatoes. page 127) are among
the mostt troublesome enemies of the bean grower; garden
aphid 4 (s under cabbage. page :31: wire-worms (see under
corn. page 95) : flea-beetles (see under beets, page 73) ; and
striped uii.eumber-lheetle see under encumbers. page 110).

LIMA BEANS
Gall Worm (Monoptiloba sp.)
In addition to the pests of other beans. lima beans are
attacked by a caterpillar tliat bores into the stems. The
plant thus attacked forms a large swelling or gall about the
larva. In this gall tile larva lives, feeding on the tissue until
its L.rowth is complete. The adult insect emerges as a small
moth. and lays eggs on the stems of the plant. These galls
are very comnuon on lima beans in Florida.
The attlaks of this caterpillar do not usually become severe
until summer. hence liina beans planted early usually produce
a fair crop. The only practical means of preventing this
injury seems to be to plant as early as possible and fertilize
and cultivate well.
Bush lima beans are not as much injured as the climbing
varieties.
BEETS
Blister-Beetles
These long, slender beetles feed on a variety of truck plants,
including beets, tomatoes and potatoes. In the Northern





D)EPARTMENT OF MGRICt'I.TI'HE


States these insects are known as "old-fashioned potato bugs"
to distinguish them from the more recently introduced "Colo-
rado potato-beetles." They are known in parts of Florida as
"Yankee bugs," perhaps from the bluish color of certain
species. The adult beetle crushed against the skinl causes a
blister, hence the name "blister-beetle." It is also called
"Spanish fly," certain species being the source of the drug of
that name.
Eight species of blister-beetles are more or le.; trouble-
some to vegetation in Florida. The most common one is the
gray blister-beetle (Epicanta heterodera) which has no stripes.
The striped blister-beetle (L. vittat) (Fig. 61) is frequently
seen.
The work of all the species is about the same except that
each shows a preference to different plants. They strip all
the softer parts of the leaves, leaving only the
midribs. The beetles usually feed in colonies.
sometimes so large that they quickly strip and
ruin a patch or an entire field.
If the colony is small the quickest way to
exterminate is to collect the beetles in a pan
rP o. I.- of kerosene. They are quick to take alarm and
SttPerd the collector must work rapidly. If the colony
Sate r'li is large the plants should be sprayed with lead
Prol mS. arsenate. The larvae feed on the eggs of grass-
S. Bur. of hoppers and are beneficial to agriculture. For
int.)
this reason it is better, wherever possible, to
drive the beetles from the field rather than to poison them.
To do this, use a bundle of twigs with which to whip the
plants and work with the wind, driving the beetles quite a
distance to prevent their quick return. It may be neessary
to repeat this driving frequently.
Beet Leaf-Miner (Pegomyia vicina)
This insect belongs to a large class made up of small
pests which often escape the notice of the trucker because
of the small size of the insect and the wound inflicted, while
the unthrifty condition of the injured plants is laid to a lack




PI.ANT DISEASES AND PESTS


,of fertilizer or water. Collectively they inflict severe am-
it ie.
This uaii.got-like larva of the two-winged fly frequently
ulrro\ms in the tissue of beet leaves. If they become numer-
..,, lhey will materially check the growth of the plants.
In it pirotectedtl position. thlie rul cannot be reached by
MiIy inlise tieide. hut the grower can cheek an outbreak by
desttroying all infested leaves. This at least should he done
when the beets are .rath.ered. if not before. If the infested
leaive.'s are left in (lhe fill ile grubls lhaie opportunity to enter
lthe' L'roumi. io into the IIpal stage and emerge later ais flies.
Flea-Beetle
This is a small oval beelle (Fig.r. 621 that gets its name
tfriii th hailit of s1tickly sprillginni' several ilelies well dis-


/


d


PF


LbL


FIO. 62.-Strawberry flea-beetle: a. Adult; b. eggs on
leos. c. side-view of young larva: e. dorsal vlew of
larva: f. pupa. Greatly enlarged. ,Prom U. 8. Bur.
of Znt.)
i lurled. Two species are mlore or less troublesohi in Florida
to beeIt,( eHabbl e. (.ll(eneiill ers, tomatoes iand related plants.





DEPARTMENT OF AGRICVLTI'RE


They eat the epidermis on one side of the leaf and the soft
interior cells but leave the veins and other hard parts.
Bordeaux mixture is usually efficacious in preventing injury
by these insects. The mixture can be made more efficient
by the addition from 8 to 16 ounces of powdered lead arsenate
(or 1 to 2 pounds of the paste) to 50 gallons of the Bordeaux.
One common species of the flea-beetle is usually very
abundant on evening primrose (Oenothera sp.) from which
they often spread to cultivated crops. These weeds should
be destroyed around the edges of truck fields as well as ii
the fields.
Striped Morning-Sphinx (Celerio lineata)
The larva of this very common hawk-moth feeds occa-
sionally on beets, although its common host plant in Florida
is purslane. It has the size and general appearance of the
tomato worm and belongs to the same family. Its life his-
tory is similar and the control measures are the same.

Larger Beet Webworm
There are two species of small moths of the genus Hymenia
Ior Zinckenia) whose caterpillars attack the beet. The larger
one is the spotted beet webworm (Hymenia perspectalis). This
larva is a small green caterpillar with purplish dots on its
head. The adult moth is a little over an inch in width across
the wings. It is cinnamon-brown in color with narrow white
hands in the middle of the front wings. The eggs are about
1/50 of an inch in diameter and are laid on the leaves of the
beets, and particularly careless-weed (amaranth). The latter
is probably its original host plant.

Small Beet Webworm (Hymenia fascialis)
This small webworm is much more abundant that Hymenia
prspectalis. During July the moths collect about the blos-
soms of catnip and other plants in great numbers. As with
the other species the beet is a minor host plant for this insect,
whose larvae live chiefly on wild plants. The moth is smaller





PI.ANT l)IS[EAK'Es AI) ADESTS


than the other species and the white bands of the wings are
larger. Either species can he controlled with lead arsenate.

Cutworms
These greedy pests seem to be especially fond of beets, the
leaves of which they cut off. If this is repeated continuously
the plant is unable to grow. For control see cabbage.

Other Beet Pests
otherr insects which attack beets are: Wireworms (see
nider corn. page !95): white grubs (see under potatoes, page
12s'): hean-.jissidI 'see Ibeein hlef-.hopper under beans. page 66):
harleqiiii eHnbalbaL'eh-bI, (see under cablbace. page 87): sweet-
jitlato <-ail.erpillar ,A*,-' under sweet pmitatmlN. page 1:) ): 12-
Ip(oltted Diahroti'n or corln root-worm (see under corn. page
101 : mand aibbhge looper (see under eablbage, page 78).



CABBAGE
lan y (abbage insects also attack collards, cauliflower.
hruissiei sproIts. kohlrali. amnd Chinese cabbage.

Cutworms
Cutworms arc very fund of any succulent plant, and are
troublesome to most truck and garden crops. Cabbage is
ione of the chief sufferers from their attacks. They gnaw
off the young plants just above the ground, making them
worthless.

Cutworms are the almost harmless larvae (Fig. 63. a, b,)
of any of several species of moths of the Noctuid family.
The moths are night-fliers and are commonly seen about
lights. They are grayish or brownish in color and most of
them have on their fore wings small silvery markings, dots,
dashes. or commas (Fig. 63, d. e).

In Florida they do not hibernate but are active and breed
throughout the year, although neither the moths nor the





DEPARTMENT OF AGRICULTURE


caterpillars are active during







a10 b
Ct^


a ;40


FIG. 63. Cutworm moth iMametra
chenopodll: a. b. Larva; c. pupa: d.
moth: e. wing of moth, enlarged.
Natural size. (Prom U. S. Bur. of
Ent.)


the coldest nights of the
winter. The caterpillars
will remain active at a
lower temperature than
the moths, but the latter
are to be seen about lights
d(urin g warm evenings
even in inidwiltter. The
worms suspend operations
during the coldest nights
only when the tempera-
ture drops below 45 de-
grees.
There are no definite
broods, caterpillars of all
sizes, eggs and moths are
to be seen at one and the
same time.
Control.-The moths by


preference
(Fig. 64)


heavy sod land. The larvae feed on the
grasses. Consequently, on land that has
no considerable grass, the cutworms are
most troublesome. As long as the grass
is available there is so much food in pro-
portion to the number of worms that their
feeding is scarcely noticeable. But when
such land is plowed, the normal food sup-
ply of the caterpillars is cut off and they
are concentrated upon the relatively small
amount of vegetation of the farmer's crop.
When tile grass land is plowed measures
should be taken to kill the cutworms pres-
ent before the crop is planted. To do this.
prepare the land ten days or two weeks
before the cabbages are set out. During
this time many of the cutworms will leave


lay their eggs
on grasses ill


6



FIG. 4. Eggs of
cutworm moth
(Agrotls saucial:
a. S i n g l e egg.
great y enlarged:
b. egg mass on
twig. Natural
size. lProm U. 8.
Bur. of Ent.)





IP..LAN Tls-.ESEs AND) Imrs


ill thie of sto vat titt l ill i tail t' I he It tillallder 4e'dve'IoI a g4 l"l it p-
I e jt'. tAity ill- t w\o Ivttfoirit lIte cro'olp is to hi' st't ouit. elit
-Allill' gre.uell 1141 %'ltvialle'ull laihtits. mswllt as i uls r'l S. col rd'. cow-
liev... ele.. z11 l dell tit-IIi ju1tel it, %lroln. ,ilitioni of Paris gmree'
itlmi itt oU tnic tol it~atlt tir watler. Sctatte'r 66ti. atiluit tlt-.
rielw a frltr 5 for t he it. ,imitg eli? 1torials 10 fecdi Iillt ieu (lt rilig
Ille Ii'glit. 111-14-1141 I lp e tit- 'e'tll Illtttt'titl t r ia t iile fol iiig w iid.
sribrl lssioi-A.* hat it miatY lit imd


A. Bran 20 pouhds
Cottonseed meal 5 pounds
Paris green 1 pound
B. Water 2 I allons


Mix (li' OlIe rli. (etts1olltwell IMteatl atld Pllaris vret'it tI l(iollglly
e still dry. thlet' wl -e with **It** 1hfilt it is decidedly
418a1a10, inot %Itypy,~. aittl 4,r %ltcii estit it i hat it %%ill fall it,
fltet flatke'. uht- lie u !4'it lorirgeujelet 4'Ve-*r II limiutie nit. is soitl
N. )llit oult after'I Slllh-el -411 t~lill it %%ill It(- 1111d attrac ltfl(l(tive(
wHlu't Owii' wolunis (OIttle' litint Iii heidI ill tilit might. If th- follow.
itig sla% is vittid. tilt- l'Iit will Ieusait as rartil .* fetor tilt secoltl
tiirllt. eatiteru iv* it will tieed to lis re'tow'edl if the cittworont have
uuit Ii".ii breiilglit t ier iost? itnil If prIop erly somnvi it will fall
illst~icit smattll fiike-.s tiunt row~ls or ltei' birdls will ntot picek
it up. Ill a vallbin't. fit-14. (nettIter protec~tion wll be gi veylcl 11)
ties' islamits tt an smaller exiH'iidittsre for ainate'rial if. jinsteatl of
lvilitg sowlS Ii"Ntlessiia~. till- Isatit i.; placedl itt -.ttatli jlile'n about thei
NtatIks of tilt- cuiibhage*. Pill *troteitiiig otlei crc ips it Iaty hit'
sc'astte'red along tille rows. 111 steatl of bothIL1 tttolliseec I itcal Haiad
iorant. either ,taeI. he Iu 1 a14o111P, ill Wili (M COS' 2.i Jmitillds is used.
tale' brat. or tis'aal %ltoltiel imit lie used in itiakitig this bait. The
mixtuxitre' Imtusst lie matitac tillp fresh e'eh dlay fromts 54'd'et rre'sit
malterial.

lie a itanll gaerte' tor ill a field wlhern- tha4ren air. loi fe'w cut-
woiews. thie caisiitt. 41ficktst need ehuea;csst masethodli elf dealingi
witIt thiena is to) walk thIrough tIllte patchi int till earlyI aiolrnilng
Hetld look for' plattits wbIe h were ctit ot iitirE tlnilt. I e'i seeediits





DEPARTMENT OF AGRICULTURE


night. By scratching the earth away from the base of the plant
the culprit will usually be found at a depth of not more than
an inch. They may be collected and fed to chickens.

Cabbage Worms
At least five species of caterpillars feed on cabbages and
related plants in Florida. The most common one during the
cabbage growing season, the winter, is the cabbage looper.

Cabbage Looper (Autographa brassicae).-This larva
(Fig. 65,a) of a Noctuid moth is closely related to cutworms,
which it resembles in general shape. It does not have the cut-
worm manner of
feeding but works on
the surface of cabbage
leaves both day and
night. It injures the
leaves by eating holes
in them and also
/1./ damages the appear-
S/ ancee of the heads by
6 soiling them with its
excrement. The cat-
; pillarlr is light green
in color and grows to
PIO. 65.-Cabbage looper: a. Larva: b. pupsa lentll of more than
c. adult. Natural size. tFrom U. 8. Bur. an inch.
of Ent.)

The eggs, yellowish-green in color and about a fiftieth of
an inch in diameter, are scattered over the surface of the leaves.
The caterpillar requires about 3 weeks for growth and spends
about 2 weeks in the pupal stage.
The adult moth (Fig. 65,c) also looks much like those of
cutworms, and, in the attitude of Gainesville. may be active
all winter.
The Cabbage Plutella (Plutella maculapennis).-The
cabbage plutella (Fig. 66,a). a much smaller caterpillar than





PIANT l)IHEASES ANDI PESTS


tihe looper. is tolmlmoll
on cabbages. It is less
thaii a half-inch long
and is 1niuech mllore hairy
in appearance thlia 1111 thflre 1" -
looper. When lditurbed
it drops (Iqikly front --
lhe plant. p)inlliing, a a'" 1 H 1
silken lthreati which it
uses I) 'relliolHit I lit\\iI e
the ilanlge'lr is ovel'. (1 Fp 66.-Cabbage plutella: a. Larva: d, e,
t t h pupa; f. moth: h. moth at rest. Two
tle lull Se o1 the and one-half times natural size. (Prom
leaf. it IlilakqI's s aill U. S. Bur. of Ent.)
roliin holes, rarely exttendinlii through. Like lhe looper, this
caterpillar i., active all winter in the latitude of Gainesville
ail(I south. Tit'he c(. to( pilaie oil lhe leaf is a loosely-woven
affair through whici theli pupa VFig. (ii.e) may be seen plainly.

The adult (IFi,. 66. f is a small moth .' of an inch across
the expandedt wings. which are gray with a border of lighter
areas. When the wings are folded in the resting position
Fig. 66, hi these areas form diamond-shaped patches along
the back. For thiu reason tlie' ioth is also called the "dia-
amoind-back" nlmth.

The life history otteupies from two to three weeks in sum-
mer. It spends about three days in tlhe egg stage, from one to
two weeks in the larval. and from four to eight days in the
pupal stage. Therefore, if one wishes to effect a thorough
clean-up of a hIeavy infestation of this insect. he should give
the plants Ia second spraying about tell days after the first
(two weeks in winter,'.


Cabbage Butterflies

The caterpillars of these white butterflies are injurious
to late cabbage ant collards. They do not seriously trouble





DEPARTMENT OF AGRICULTURE


the main winter-grown crop of cablage be-
cause they are not active at that season.
Imported Cabbage Worm (Pontia rapae).
- in the northern and western parts of the
State the most common cabbage butterfly is
tile imported cabbage worln. a pest which was
brought to this country about 1 .(i. It has since
spread over tile entire country. reaching Flor-
ida about 1!S90. hut has never become as iabun-I
dant as in the Northern States.
The full-grown eaterpillar (Fiig. 67. a) is
PIO. 87.- Ira-
about 11/4 inches long. bright green with a yel- ported cab-
lowish line down the middle of its back and a ny a. Lurvr:
row of spots of th(e same color along ips sides.. NUra psN
Two or three weeks are required for its growth. r.ofm E.:, .
It then crawls to some sheltered place and there
transforms into the pupa (Fig. 67. b) and 8 or 10 days later.
in warm weather. the butterfly (Figs. (iS. 6(9 emerges. Iut










FIG. 6.-Imported cabbage buttcr- FIO. 68.-Imported cabbage butter-
fly: Male. Natural size. iFrom fly: Pemale. Natural size. 4From
U. S. Bur. of Ent.i U. S. Bur. of Ent.P

those which enter the pupal stage in the late fall remain there
all winter, at least il thle northern part of the State. The eggs
are white or yellow in color and are scattered over the surface
of the leaf.

Native or Southern Cabbage Worm (Pieris protodice).-
This worm (Fig. 72. a) is similar in appearance to the imported
worm but has four lonlitudinal yellow bands. The butterflies
can be distinguished by comparing the illustrations (Figs. 6A.





P'LANT1 DISEASES ANID I'EST'


(!9. 70. 71). The nature of the injury it iltnflicts is idenicial
with that of, the species last t iin1ed.










FIO. 70.-Southern cabbage butterfly FIG. 71. Southern cabbage butterfly
Male. Natural -oe. 1From U. S Pemale. Natural c tie. From U. S.
Bur. of Ent., Bur of Ent.,

Gulf W'hitT (Pieris monuste). This luterfly has ia yel-
low caterpillar ( VFi. 73:. a with four lonigit udinal stripes of
a lpurplish hu It is 11] i. ncies loni,. Thl bluttcerfly lFig.
7:1. c) is the largest of the L'rolup. mileasn initg early :1 inclles
i'cross t expa ltided wiinls. This i-s hy firll the most conlnlon
ai1(l t4roublesolite <-atel'rpillr o, .il ( bltab i. 1l t o llairl" s Yrowll d111-
inly the late spr lintg ail
ttuinner in ll he solithernt

Control.-Any or aill
of these eat erpillars on S
yonnlg plants are iatsily
e4oltirolled by meanvls o01
a irsellien ils. (O)nl i (1111 IIsp
arises greeli bitt either
lead O' (a9 ilitt i it sellate
is rf llle.. (le I I,,, FIO. 72. Southern cabbage butterfly: a. Larva:
Is ptreferabh. (ie pound b. pupa. Natural size. From U. S. Bur. of
"of Paris greene or '2 Ent.
ipotds of lead or calcium aimsettte powder i into 0 3(al-
lons of water. This liquid usually does nott slick well to eabhbagl
plants on accitout of the bloomml" a wiaxy coting. To make
it stick. add soap wlhen the mixture is made. at the rate of or ti
pounds for 30 gallons of water according to whetller the water
is hard or soft. .ny alkaline laundry so l will do. Flour-
paste is also a good silbstlale to make the arlsenlic (.compound111





I)E1'-kRTMENT O1F M(JRlCfTI4TURE


stick to cabbage leaves. A paste made by boiling 2 pounds of
flour in 2 gallons of water may be added to 50 gallons of the
arsenical solution.
A spreader recommended by the Illinois Agricultural Ex-
periment Station is made by dissolving 5 pounds rosin and
1 pint fish-oil soap in a gallon of water in an iron kettle. Then
add 4 gallons of water and 1 pound of concentrated lye or
potash and boil for a few minutes. When ready to spray, add
to 32 gallons of water 2 gallons of the above solution. 6 gal-
lons of milk obtained by slaking quick lime in water (strain it
so as not to clog the sprayer), and I," pound of Paris green or 2
pounds of powdered lead arsenate.
A new "spreader" worked out by the U. S. Department of
Agriculture is a solution of cactus. Thirty pounds of cactus is
chopped fine and allowed to soak over night in 50 gallons of
water. This is strained and the arsenic added. In those parts
of the State where some of the wild species of "prickly pears"
or spineless cactus grow. this should make a cheap "sticker."
Arsenical poisons may be used dry if applied when tile cab-
bages are wet with dew or rain. It is well to use a filler of
c I heap flour
or air slaked
or hydrated
lime, mixing
about six-
teen parts of
t hle filler to
one of dr y
poison.
Of the

"-l YCp opounds.
Paris green
is the least
satisfactory.
Its arsenic
Content is
FIG. 73.--ulf white butterfly: a. Larva: br pupa: c, adult variable and
Natural size. (Prom U. 8. Bur. of Ent.) a f t e r the







cabbages begin to form heads arseiicals must not be based ac
any arsenical resi(due on the product going to market will subject
it to seizure and ldestruction hy the government.


Cabbage Plant-Lice

The common aplid on cabbage is the .arldeln aphid or so-
called green peach-aphid (Myzus persicae), althoug'i the cab-
hage plant-louse (Brevicoryne brassicae) (.'i,. 74' and the
turnip louse (Aphis pseudo-brassicae) are ;ilso found.

Thie iardein iapliid is hriihlt vreeii in color and sinoouth, while
the others have a more
imlealy look. and the tur-
^ I>nip louse is quite hairy.
The- character of the
Damage. the life history.
; anl the means of con1-
trol are the same for all
Stlhree species and prac-
tically the same for all
FIG. 74 -Cabbage aphis: a. Winged female. .llilS.
b. wingless female. Greatly enlarged. iFrom
U. S. Bur. of Ent.' Aphids suck the juices
from the plant on which they1 live. stlnting its growth. causing
the leaves to curl. turn yellow. and finally, the plant to die.
They multiply with great rapidity. often beginning when only
a week old and producing several young, each day. During
warm weather, which means tlhe entire year in Florida. the
individuals of most species bring forth young parthenogenetical-
ly, that is, without mating bet ween the sexes. Indeed. during
that time of the year males are usually not produced at all.
Usually the young are horn alive and active, the eggs hatching
before they are laid. But with thle coming of winter. in more
northern states, males and true females are produced and eggs
are laid which do not hatch until spring. Most individuals
never acquire wings. but from tilme to time winged individuals
are produced and spread the species from plant to plant.


PLANT 1' )TSEA-Ss F1-1A AND PENTS





1l)lEA I(T'-IMENT OF AGRucIC'1'rURE


jFarther north tile green peaci-apihid slpeds the winter in
the egg stage on peaches, plums. etc. The first two or three
generations in tihe spring feed on the tender unfolding buds
of those trees. The first generation is pink in color but their
young are green and never become pink. The second or third
teiieerations usually develop wings and leave the trees for tender
vegetables where they live all suinimr. This annual migration
is (eoliiiion among aphids, and the last generation returns to the
trees inl the fall to lay eggs. enabling the species to get an earlier
start in tile sprillg tlian would be possible were it Inecessary to
wait for herbs to grow.

Aphids give off a sweet substance called honeydlew of which
ants are very fond. For the sake of this lioneydew ants care-
fully tend aphids, often protecting them from their enemies
which they drive away. They may carry the )aphids or their
,',rgs from place to place where tlhe posturee" is good, carry
the e'ggs into their nests to winter over, or even build adobe
sheds over then for protection from rain and enemies. For this
reason al)hids are often c l called ants' cows." Hence it happens
that thi presence of excited ants on a plant is often the most
e*vidleit sign of the presence of aphids.

Remedies.-For the control of aphids on cabbage, the best
remedy is to spray the plants with a solution of tobacco extract.
'For directions for making this see melon aphis under water-
melons, page 133. On cabbages a spreader of soap and flour-
paste slhold be used as recommended in the discussion of cabbage
worms. If the worms and thie aphids are both present on the
cabbages, the tobacco can be added to the lead arsenate spray.
killing both pests at one time.

Dusting the plants with tobacco dust is of some benefit, and
will often keep down the number of aphids and prevent all
oiUlbreak, but will not control effectively an outbreak that has
,ailled headway. These outbreaks often start on plants scat-
tered through a field and by pulling them up and destroying
1 hle a general outbreak can be forestalled or at least delayed.





PLANT DISEASES ANi) PHS'I'S


Enemies.-Aphids are a very attractive article of diet to
a large number of enemies which are usually able to hold them
in cheek. Only the wonderful rate of reproduction of the
aphids enables them to have a surplus with which to start a
destructive outbreak after supplying the "market" of their
enemies.

The smaller birds. such as wrens, fly-catchers. anld w\arblher%.
destroy great numbers of aphids. A flock of young chickens.
if given the freedom of the garden. will do excellent work ill
ridding it of aphids.

In i colony of aphids. dead oneis imay lie found which art.e so
greatly swollle as to be nearly spherical in shape. T'lhese have
been killed by the larva of a minute wasp-like parasite which
lives inl tile interior of tile aphid., conslmingl its vitals. The
parasite pllpates ill the dead aphid anil when ll e adult parasite
is ready to emlergl it bites a hole ill the top of tile aphid aind
crawls out. The egg from which the parasitic larva hatches is
laid inside tlie aphid which the female parasite pieces Nwili
her ovipositor.

Several kinds of soft-bodied larvae move among the aphids
and destroy tlem. Some are legless maggots which impale
aphids on their sharp anterior ends and suck the bo dy fluids.
These are the larva of a family of two-winged flies, known as
syrphus-flies. There are many species. Another larva is flat.
wedge-shaped, with well-developed legs and a pair of jaws with
which it pierces the aphids. These are aphid-lions. The adults
are lace-winged flies (Chrysopa), bright green insects which
measure nearly an inch across the four galzy wings and have
Iri.ght golden eyes. The eggs are laid in groups andl are raised
on stalks a half-inch above the surface of the leaf. This arrange-
ment prevents those first born from using for their food the
unhatched eggs in the group. A similar larva (Hemerobius)
makes a case to cover its body out of tile remains of the victims
which it has sucked dry. This case is carried about by the larva.
hence it is called a "trash-bug." The adult is similar to the
golden-eyed lace-wing, but is brown.




DEPARTMENT OF AGRICULTURE


Aphids are the choice food of many lady-beetles and their
larvae. The species most common in Florida truck patches
and gardens are the convergent lady-beetle and the blood red
lady-beetle, although the twice-stabbed lady-beetle, so common
and beneficial in citrus groves, is occasionally found.

During the rainy season aphids are subject to attack by
fungi, particularly Empusa aphidis. This fungus often de-
stroys in a few days the aphids from the whole fields.
The heavy rains of the Florida summer are directly destruc-
tive to aphids which' are knocked off the plants and beaten to
death on the ground.

Cabbage Root-Maggot (Phorbia fuscipes)

These small, soft-bdlied legless maggots (Fig. 75. a) which
often do great damage to the roots of cabbage and related plants
in the North are comparatively uncommon in Florida. The
first indications of their presence on the roots are a check to
the growth of the plants which wilt during the heat of the
day and show a bluish, sickly color. The plants finally turn
yellow and wilt down completely. If these plants are pulled
up it is found that the roots have been eaten off, and perhaps
the main stem mined,
lby the maggots, which
are about 34 of an inch
long when fully grown.
The adult (Fig. 75,
c) is a two-winged fly,
W / ^similar in appearance
I to the house- or ty-
Ie phoid-fly but much
~ smaller and with a pro-
portionally longer ab-
( domen. The female lays
S'her eggs on the stem
Fn. 1.-Cabbage root-maggot (Phorbia braslcae): of the plant or on the
Larva; b. pupa; e. female fly. About fourrond nea
times natural size. (From U. 8. Bur. of Ent.) ground near by.





PLANT ]ISEXSEs ANI) IAND 's


Remedies.-Repellents placed about the roots of the plants
when first set out are of some benefit in discouraging the fe-
males from laying their eggs oi the plants. Perhaps tobacco
dust is about as practicable as any. Carbolic acid emulsion may
ie used. Liberal fertilization will enable the plants to outgrow
the damage done by a few maggots. Repeated shallow culti-
vation will destroy laInyv of the eggs laid oni tie ground about
the bases of the plants. The grower should destroy all heavily-
infested plants and should avoid planting cabbage on land that
has just borne a crop of infested cruciferous plants whether
cabbage, cauliflower. collards, rape. mustard. or turnips. The
maggot will breed in wild plants of this family and all such
found near the field should be destroyed.
(abbages in an infested seed bed ran Ibe trealed with carbon
bisulphide. To do this. make holes with a stick three or four
inches from the infested plant and slanting obliquely under it.
Pour in about a teaspoontful of the carbon bisulphide and quickly
tramp the soil solid to confine tlie flumes.

In the Northerni Stales it has been found profitable after
setting the plants in the field to protect them front the attacks
of this insect by using tarred paper discs. These are cut open
along one radius and fitted closely about the plant. It is doubt-
ful if the attacks of the insect in Florida fields are sufficiently
common to make this precaution profitable except in the case of
some particularly valuable plants.


f .

I U
FIG. 76.-Harlequin cabbage-bug: a. b.
Nymphs: d. e. egs greatly enlarged;
f. g. adults. Slightly enlarged. (Prom
U. 8. Bur. of Ent.)


Harlequin Cabbage-Bug or
Calico-Back
(Murgantia histronica)
This strikingly-colored in-
sect. a native of the Mexican
region, has been slowly work-
ing its way eastward and
northward. It is not as yet
abundant in Florida but may
le seen occasionally on late
cabbage and is quite common





DEPARTMENT OF AGRICULTURE


and dest ruetive to collards that are carried through the summer.

The adult (Fig. 76, g) is black and orange and is 2-5 of an
inch long. Both the adult and young suck the juices of the
plants into which they inject a poison. A few bugs are suffi-
eient to cause a plant to turn yellow and die.
The eggs (Fig. 76, c, d, e) are deposited on the under side
of the leaves. usually in two rows They are keg-shaped. white.
with black lands and a small black spot on each side. increasing
the resemblance to a keg with its hoops and bung-hole. They
hatch in 3 or 4 days. The young are at first yellow. developing
the orange markings later.
They are usually present in such number as to make hand
collecting practical. but hand collecting of the young is less
satisfactory because of their small size. Should these become
abundant they can be killed by kerosene emulsion. Destroy
all infested. dying plants. In the northern part of the State a
crop of late cabbage can be partly protected by planting an early
trap crop of mustard, radishes or turnips. When this trap crop
bIcomnes infested it may be sprayed with kerosene emulsion or
pulled up and burned.
Cabbage Hair-Worm Or
Cabbage Snake
(Mermis albicans)
This whitish, thread-like
worm (Fig. 77), which some-
times grows to be 2 to 9 inches
long. is frequently found in
cabbage heads. It is an in-
ternal parasite of grasshop-
pers and caterpillars and it
?0. 77.-Cabbage hair-worm or cabbage
snake. (Prom U. 8. u of Ent.) gets into the cabbage by
crawling out of infested insects. It is therefore a friend of the
--rower. In spite of its repulsive looks and the many stories
which are told of its poisonous nature, it is entirely harmless
to mankind.





PLANT DISEASES ANDI PESTS


Southern Squash Bug (Anasa armiger)

TIiis insect sometimes attacks cabbage and rollards. It lreeds
oil these plants. as eggs and nymiphls are fouid there. (Control
is similar to that of the squash mhu. page 13:2.

Other Cabbage Pests
IThe following g inamied insects also ilnfest cabbage iln lorida:
Blister-beetles (see under beets. ,page 71) ; flea-beetles ( see under
beets. page 73) ; oioni thlrips see niidehr olliolls. pae 11 :
wirewornis (see iilnder corni. page 95) i nematodes (see root-
knot under general garden pests. page (65 1 : and irasshliopper.s
(see 1un1der general garl'den I)ests. page ')4 i ; s'ripetlliti- Ieaf-miner
Isee Uill'er (cowples. page 10.3).



CANTALOUPE
Tlie insect pests of this ,riop are identical with tliose 4,i"
elcllllers. I See (.enlcumbersl lpage 106 1.


CARROT
Tlie comlllionl insect pests of this cr'o) ael': ('1utwo)rm11 ( see
liuder cabbage. page 7.5) ; garden aphid isee cabbage pilant-lice
inder callbage. page 83) : black blister-beetle I Epieanta
pellnsylvanica) (see blister-l eetles indler beets. page 71) : celery
caterpillars (see itunder celery, pa l e !91i : and cai rrot -beetle
(Ligyrus gibbosus) (see Mahy-beetles uideir potatoes. pa.er 128 i.



CELERY
Celery Leaf-Tyer (Phlyctaenia ferugalis)

DI)lrinig sole seasons this insect is extremely ilnjurious to
celery. The eggs are laid on the leaves. Their larvae feed chiefly
oni tle new nd111 tender leaves above fthe "heart" 'of the celery.
As tlhe caterpillars get older they descend the stalks and feed





DEPARTMENTT OF AGRICULTURE


iear the bases of the stalks until ready to pupate. During tile
later stages of growth the caterpillar spins a more or less con-
spicuous web of silk under which it feeds, hence the name of
webworm. The larva is a pale yellowish caterpillar and quite
hairy. The adult is a small brownish moth.
Control.-This insect is best controlled by dusting the plants
with pyrethrum. This may be used straight or mixed with an
equal weight of sulphur.


Semi-Tropical Army Worm (Prodenia sp.)

This insect, which feeds chiefly on grasses, sometimes attacks
celery in injurious numbers. It is a large caterpillar with
reddish brown markings. It is closely related to the sweet
potato caterpillar. The same poison baits which are recom-
mended for that insect will also control this caterpillar.


Garden Flea-Hopper (Halticus citri)
This is a minute black plant-bug (Fig. 78) that attacks the
leaves of cowpeas. beggarweeds. peppers. and a great variety











d
FIO. 78.-Garden flea-hopper: a. Short-winged female: b. full-winged female:
c. male; d. head of male in outline. Elght times natural size. (From U. 8.
Bur. of Ent.)

of weeds. The attacked spots turn yellow, giving the plant a
spotted, "peppered" appearance. The insect may be con-
trolled readily by tobacco extracts.





PLANT DISEASES ANI) PESTS


Celery Caterpillar (Papilio polyxenes)
This caterpillar sometimes strips the leaves from celery
and, as the caterpillar is rather large, a single one can inflict
much damage. It is
conspicuously colored
ini green and black. It

Comint1101 orangee dog"
(Papilio cresphontes)
land, like that species.
when d ist ur e d. it
thrusts out a yellow
FIO. 80.-Tarnished plant-bug: Adult and liorn- like process from
young. About four times natural size. (From
U. s. Bur. of Ent.) the head accompanied
by a strong pungent odor. This seems to protect the insect
from birds and possibly other foes. It grows to a length of 2
inches. The pupa is fastened to a support partly by a silken
thread about its middle. In from 12 to 15 days. in summer.
there issues from it a swallow-tailed butterfly. This is smaller
than the adult of the orange dog and much darker in color.
It is called the black swallow-tail.
Both the caterpillar and its work are so conspicuous that
hand-picking will usually be the most economical means of
control. As celery is commonly sprayed with Bordeaux for
fungous troubles, lead arsenate can be added (1 pound to .30
gallons of Bordeaux) and this, as well as all other biting insects,
be killed.
Other Caterpillars.-Several other caterpillars attack celery:
among them are the celery looper (Autographa falcifer), an
insect closely related to the cabbage looper.
Plant-Lice
At least two species of aphids commonly attack celery in
Florida. One is the common garden aphid or green peach-
aphid (Myzus persicae). The other, Macrosiphum lactucae,
is much larger. The control measures are the same as those
given under cabbage, page 84.





1)EI'MRTMENT OF AGRCI1*lTtURE


Other Celery Pests
Other insects injurious to celery are: Flea-beetle (see under
I:eets. page 73); cutworms (see under cabbage. page 75.): and
cabbage root-maggot (see under cabbage, page 86) : red spider
(see under peas, page 121).


FIELD CORN AND SWEET CORN
Sweet corn is attacked by all the common pests of corn and
there e are man of them. Some show a decided preference for
sweet corn. Only the more important insects attacking corn
will he considered here.

Corn Ear-Worm, or Bud-Worm (Heliothis obsoleta)

This common pest of cotton, corn. tomatoes, beggarweed. etc.,
prefers sweet corn to any other of its host plants. Early in the
seasonn the moth lays her eggs on the young corn. The early
n'lieration of larvae which hatches from these eggs works in the
corll as.a "bud-worm." (At least two other caterpillars that
ido very similar damage to corn are known as "bud-worms.")
Whe'n mature the caterpillars enter the ground, pupate. and in
seven days emerge as moths which in turn lay their eggs on the
silk of the corn which is by this time beginning to appear.
The second generation of larvae on the corn eats the silk and
then enters the ear and feeds upon the developing kernels.
Later generations develop on cotton, beans, beggarweed, etc.
The insect also attacks tomatoes. But whether working in
corn as the "bud-worm" or "ear-worm." in tomatoes as the
''fruit-worm." on cotton as the "bollworm." or fully exposed on
begg.arweed. it is the same insect. So abundant is this pest in
Florida that it is almost impossible to find an ear of sweet corli
that has not been attacked by at least one of these caterpillars.
Control.-The work of the first generation in the corn is
iuually noticeable when the corn is about knee high At this
stage it is not difficult to poison the caterpillars by spraying
or dusting some of the arsenic compounds into the infested





PL, ANT 1)ISEASEs ANID l'Es'Ns


i)uis. Thie writer has uiisteril itnilinItd lead .aistnate and zinc
airsenite powder into Ih lw )ils without prodw-in nll'l y harmful
effects. but it is safer and llore I ecollnomi)ill to Ilx Ix tlie ]>poisoll
with fro1m 2 to 4 times its lhlk of air-slaked or lhyrate lThe dustin is lbest do.n iln tih early mltornill wlhen thl' plants.
are wet with dew. Th1e agitation resulting frmn brushiii against
the stalks will usually he suftficient to eause tli' dewi to uni
down into ill( butd. carrying, tiI( poison with it. In a small
Lgrardeli tlie poison (ean he applied' by tmean.s iof a tin ean lpunll('hed
full Iof holes. On a large
..cahle the well-knowii bag-
and-pole mel hId 1ma.v lit-
lsed(. bh t tilte t11ost i l4,1
distribute ionl will 14 seetlred
I)y tlhe lis of ia hll.tsill,"
Illa.lille. It is in1 ortant l
Ihat this early g en14er'atioll
shoul(l bhe d4.'Stl',o.ved. it' pI) -
sible. Not only will tli -
illjllrV 1t 11o ( )illis FIG. 8i-Corn ear-worm: Adult. One and
checked, bllt tl1e IInumb'r of a halt trmes natural Lize. Orllginsi.)
caterlillars in the following ai 'ileration. wliheli works ill tie ears.
will lie lessened.
When flie silks appear on theIl younV g ears of corn they (an'
lhe dusted by means of the4' salme apparatus. iThe caterpillars
feed on the 'exposed silks for only a fre datlys before entering
the ear where they are safe from insec ti('ides. so it will be neces-
sary to repeat thie dulsting, every three( or four days. This is too
expensive for a c.rop of field (ornil. hbt oni such ah Iligh-priedl
crop as sweet cor'it is i worth while.
Inl a small patch in ithe garldell the wornsl can often ,e
removed from thet tip of thle ear before they have inflicted
material damage. In reinoviinl the worms it is not( well. how-
ever to open tlie ears to salli ain extent as to expose the
kernels, as other animals suchI as birds, Carpohilus and other
insects will thien attack tlem. Woodpeckers and bluejays are
occasionally seen feeding oni tIlhe worms and lthe ears of sweet
corin.





DEPARTMENT OF AGRICULTURE


Life History.-The eggs are whitish, oval, prominently
ribbed. and about a twentieth of an inch in diameter. They
are scattered over the corn Those from which the bud-worm
hatches are laid on the leaves; those of the ear-worm on the silk.
They hatch in 3 or 4 (lays.
The caterpillars vary from a delicate pink to black. They
are marked with rather narrow longitudinal lines. They re-
quire about 17 days for growth in summer, becoming 11/4 to 2
inches long. The caterpillar then bores a hole in the side of the
ear or stalk and enters the ground to a depth of 2 to 5'*inches
where it forms the pupa. Here it remains for a week or two in
summer or all winter if it is the last fall brood.
The pupa lies in an earthen cell. It is about /.-inch long.
It is at first green in color but soon turns to a light brown.
The moth (Fig. 1 ) which issues from this cocoon varies in color
from a dusky yellow to grayish and expands from 11 to 2
inches Unlike n\ost moths it may fly in broad daylight, but
the eggs are usually laid at sunset.

Oarpophilus
If the husk is removed from an ear of corn in the milk by
any cause, such as a woodpecker in his hunt for a corn ear-worm.
it is at once attacked by these scavenger beetles, which are also
common in decaying fruits. The beetles are brown and about
% of an inch in length. Their wing-covers are so short that
they do not reach the end of the abdomen. The beetles seem
unable to penetrate the husk of an uninjured ear. but very
commonly get into the burrows made by the corn-ear-worm and
cause further damage. They often breed among tle kernels
which blacken and decay, thus spoiling many ears that would
otherwise be usable. The larvae are small, whitish, and maggot-
like. Control measures are obviously those which control the
corn ear-worm.

The Corn Lantern-Fly (Peregrinus maydis)
This insect and the bud-worm are the worst enemies of late-
planted corn in Florida. In the latter part of August the





PLAN.\T DISEASES ANI) PESTS


lantern-fly becomes extremely abundant and severely infests
practically every stalk of young corn. and quickly kills it.
Stalks that have reached the tasselling stage are not severely
injured.
This lantern-fly is a slender yellowish-green insect about a
sixth of an inch long. Its wings are longer thal the body, and
are clear except for some dark-brown markings near tie tip.
They collect in large numbers in tlhe bud and in the axils
of the leaves. These colonies are usually composed of numerous
young of all sta~res. and a few winged adults.
The most effective and the quickest inans of controlling
this pest is to dust the bms of the corn with iicotine siulphate-
lime dust.

Wireworms, "Drillworms"
These hlng, slender, har. wiry 'worms" are lhe larvae of
click-beetles. They feed below the surface of the ground on the
roots and stems of plants into which they often bore. The in-
fested plant is stunted, turns yellow and may die. The larvae
are particularly destructive to sproutling seed. eating the inside.

The adults are failed click-wcetles from their habit of throwing
themselves into the air with an audible click when placed on
their backs. 'They are also called "skip jacks" and "snap
beetles."
There are dozens of species of wireworms in Florida and at
least a half-dozen injure corn. As their habits, life history.
type of soil infested. an1d control measures differ for each
species. it will be nceessary to take iilp the more important
ones separately.
Spotted Click-Beetle.-The most common wireworm in
Florida corn fields is the young of the spotted click-beetle
(Monocrepidius vespertinus) (Fig. 82). This is a thick wire-
worm about ..-inch long and is found in both dry and wet
land but is more destructive in the former. It is also found
on cowpeas.





I)EIPARTMENT OF AGRICULTURE


v0






FIO. 82.-Spotted click-beetle: Adult: pups: larva: and egg: greatly enlarged.
PFrom So. Car. Air. Exp. Sta..

'The eggs are laid in thel summer Tlhey hatch in about 9
days. according to )r. A. F. Conradi and II. (. Edgerton
4So. Car. Agr. E.xp. Sta. 11ul. 179). and the larvae feed until
tlhe following spring when they pupate in the ground at a depth
of froin 3 to 5 inches, remaining there about two weeks. The
,earliest adults were taken at Gainesville on *June 7 by Mr.
l)ozier. They are from 1-5 to 1-3 of an inch long.
Fall plowing and frequent cultivation of the corn will de-
stroy many of these insects, particularly if chickens or other
birds follow the plow. They are seldom found at a greater
depth than 4 inches. A few seeds of cotton planted at the same
time as the corn is said to be of benefit. They pefer the cotton
to the corn and while they are feeding on the cotton, the corn
has an opportunity to germlinate and get a start.
The nightha\wk is an important enemy of thle beetles which
fly at dusk. tlhe time when these birds are on the will. Night-
hawks should be protected by the farner.
Monocrepidius Lividus.-Associated with tlhe last-named
species in about the same class of soil is Monocrepidius livi-
dus. This is perhaps the second most common wireworm in
Florida. Control measures are tlie same as for tlie above
named species.





PrLANT D)IASEASES ANI) PES'I'S


Corn and Cotton Wireworm.-Unlike most wireworms, this
one (Horistonotus uhleri, H1orn) works mostly in sandy, light,
light, dry soils. It differs also from the other species in its
appearance. It is long and white and has a soft skin instead
of the hard. chitinous covering like the others. Control meas-
ures are about the. same as those used against the larva of
the spotted flickl-heetl.

Corn Wireworms (Melanotus sp.)-These are not as con-
mion as the other species. Like most species of wireworms
they are found mostly ii low, poorly-drained land. especially
if it was in gras the previous year. Draining and liminti the
land. with deep and thorough cultivation are important.
The larvae are about 1' inches long. brown in color and
have three small projections on the posterior end. Some
species require several years for growth. The adults are
brown and from a half to :3i of an inch in length.

Other wireworms sometimes injurious to corn in Florida
are Lacon curtus and Lacon rectangulus. The control meas-
ures are similar to those for the last-named.
Fall Army Worm, or Southern Grass Worm
(Laphygma frugiperda)
This well-known pest of grass attacks corn as a second
choice when all of the grass within easy range has been
eaten. Army worms are so named from their habit of as-
sembling in vast numbers and marching in mass formation to
new pastures These marches come as a result of excessive
numbers exhausting the food supply in the place where they
hatch. The word "fall" was prefixed by entomologists in
the Northern States and is a misnomer in Florida. The de-
structive armies usually form in July and August. but some-
times as early as April. At other seasons, and during the
years when no armies are formed, a few of these caterpillars
are found, feeding apart like cutworms.
Control.-These isolated caterpillars may get into the tips
of growing corn andl become "bud-worms" where they may be





DEPARTMENT OF AGRICULTURE


controlled by the same measures as given for the corn ear-
worms when working as bud-worms. (See page 92.) The
armies may be repelled with fair success by the "Kansas bait,"
(see page 55), or the food-plants may be sprayed or dusted
with lead arsenate. Paris green or any other arsenical. This
is applied best while the caterpillars are working on grass,
before entering the cornfield.
The eggs are laid mostly on grasses in masses of fifty or
more and hatch in about tell days. The caterpillars require
about two weeks in which to become full-size, which is about
]I' inches long. They are rather slender. Their color is
brown with a narrow yellowish-gray stripe along the middle
of the back and a brownish-black one along the side. On
the head the central line branches, making a conspicuous
V-shaped white mark, which helps to identify the caterpillar.
The body is covered with small black prominences from each
of which a short, stiff, black hair arises. The adult is a moth
resembling those of cutworms, to which it is closely related.
Root Webworms (Crambus sp.)
These also are caterpillars that often do severe damage
to young corn in the spring. In April, 1914, they destroyed
many acres about Gainesville and other places. They always


l(^\JvhlP


d, adult. Greatly enlarged.





IP)LAN' J)DSEASES ANI) PEsTS


do more danlage than they are charged with. much of their
work being attributed to cutworms. There are several species
of these insects, but all of the caterpillars are reddish, pinkish
or brown. with conspicuous dark spots on their backs. Like
cutworms, they feed at niiht. but do not cut the plant off.
Instead, they strip it of its leaves. make channels on the
surface of the stalk. or mine the center. They construct a
tube of silk just below the surface of the ground and hide in
this during the day. This will distinguish
them from cut worms. Furthermore, they
try to escape when disturbed instead of
curling up and "playing possum" like
cutworms. The adult insects are small.
light-colored moths which are always
plentiful in sod land. When at rest they
roll their lwinis around their bodies in-
stead of laying them back more or less
flat I i k e most
moIlths.
Control.--
S Severe injury
by these eater-
pilla.rs is on-ll-
finied to land
which had con-
siderable grass r
during thile pre-
e (d i 11 g year.
Sitch1 la9nd. if
intended for( 7
corn. should be
broken as early
inll tlhe fall as -

Aside from tile
matter of inseet
olntrol, this is PIG. 84.-Injury to corn by bill-bugs. tFrom U. 8.
Bur. of E~nt.)




DEPARTMENT OF AGRICULTURE


also the best procedure from the cultural standpoint, as it
conserves the moisture during the dry winter. Some relief
can be obtained by dusting or spraying the young plants
with lead arsenate.
Bill-Bugs (Sphenophorus spp.)
Other insects that injure young corn are species of snout
beetles called "bill-bugs" (Fig. 83). They feed on the young.
tender leaves, making parallel rows of holes, after the pat-
tern of sap-suckers on trees (Fig. 84). This is done when the
leaf is rolled up in the bud and each row of holes is produced
by a single puncture.
Like the last-lamed insect, this one is injurious only on
land that grew much grass during the preceding year. Eggs
are laid on grasses in low wet land. where alone bill-bug
injury is ever severe. The young feed chiefly on the roots
of grasses, but one species (8. robustus) may live in the pith
of the corn stalk.
The measures recommended for use against root webworms
(page 98) are also the ones to be used against bill-bugs.
Corn-Leaf Blotch-Miner (Agromyza parvicornis)
This larva of a minute black fly makes irregular shaped
blotches in the leaves of corn and some grasses by eating the
tissue from between the lower and the upper epidermis. Its
injuries are most noticeable and serious on young corn. The
egg is laid in the corn leaf and hatches in 3 or 4 days in sum-
mer. The larva feeds from 3 to 12 days in summer. It breeds
during the winter in southern Florida (JI. Agr. Research.
April 12, 1916).
The insect cannot be reached by any insecticide. The only
course is to pull up and destroy badly infested plants, and
by good care, keep the others in such a vigorously growing
condition as to overcome the injury. An excess of corn should
be planted so that a good stand will remain after the require-
ments of the flies have been met and the infested plants
pulled up.




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs