• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Table of Contents
 General remarks
 The horn-worm: Tobacco worm
 The suck-fly
 The cigarette beetle
 The tobacco leaf-miner
 Cut-worms
 Grasshoppers, or locusts
 Spraying apparatus
 Back Cover














Title: Preliminary report upon the insect enemies of tobacco in Florida
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 Material Information
Title: Preliminary report upon the insect enemies of tobacco in Florida
Physical Description: Book
Creator: Quaintance, A. L
Publisher: Florida Agricultural Experiment Station
Publication Date: 1898
Copyright Date: 1898
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Bibliographic ID: UF00024509
Volume ID: VID00001
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Table of Contents
    Front Cover
        Front Cover
    Front Matter
        Front Matter
    Table of Contents
        Table of Contents 1
    General remarks
        Page 154
    The horn-worm: Tobacco worm
        Page 155
        Page 156
        Page 157
        Page 158
        Page 159
        Page 160
        Page 161
        Page 162
        Page 163
        Page 164
        Page 165
        Page 166
    The suck-fly
        Page 167
        Page 168
        Page 169
        Page 170
        Page 171
        Page 172
        Page 173
        Page 174
    The cigarette beetle
        Page 175
        Page 176
        Page 177
    The tobacco leaf-miner
        Page 178
        Page 179
        Page 180
    Cut-worms
        Page 181
        Page 182
        Page 183
    Grasshoppers, or locusts
        Page 184
        Page 185
        Page 186
    Spraying apparatus
        Page 187
        Page 188
    Back Cover
        Page 189
Full Text




BULLETIN 48. OCTOBER, 1898.


Florida Agricnultral Experimont Station.


A Preliminary Report Upon the
Insect Enemies of Tobacco


in Florida.


By A. L. QUAINTANCE.


The Bulletins of this Station will be sent Free to any Address
in Florida upon Application to the Director of the Ex-
periment Station, Lake City, Florida.


DELAND, FLA.
E. (. PAINTER & CO.,
1898.


















BOARD OF TRUSTEES.


HON. S. STRINGER, President.................... .Brooksville
HON. F. E. HARRIS, Chairman Executive Committee. ...Ocala
HON. A. B. HAGEN, Secretary. ..................... Lake City
HON. F. R. OSBORNE.................... ............ DeLal
HON. Wm. FISHER............ . ........ . .Pensacola
HON. F. L. REES..................... ........... Live Oak
HON. E. J. VANN ................................ Madison


STATION STAFF.



W. F. YOCU T, A.M., D.D......................... Director
P. H. ROLFS, M.S ............... Horticulturist and Biologist
H. E. STOCKBRIDGE, Ph.D .................... Agriculturist
A. L. QUAINTANCE, M.S. ..................... Entomologist
HI. K. MILLER, M.S........ ............. ........ Chemist
W. P. JERINIGAN ................... Auditor and Book-keeper
JOHN F. MITCHELL. .............. Foreman of Lake City Farm
LIBIRARIAN .... ..... ......................... Lake City














CONTENTS.




General Remarks............... ................... 154
The Horn-Worm: Tobacco Worm ...................... 155
Life History and Habits .......................... 156
Description. ................. ............... .... 158
Treatm ent.... ........ ......... ................ 160
The Arsenic Left on Tobacco ................... .. 162
Summary as to the Use of Paris Green on Tobacco .... 164
Arsenate of Lead.............. .................. 165
Enemies of Tobacco W orms ....................... 166
The Suck-Fly................ ............ .. ..... 67
Life H istory....... ........ ... .... .. ..... . 169
Appearance of the Insect............. ............ 171
T reatm ent..... ............ ....... ............ 172
The Cigarette Beetle............... ... ............. 175
Description........ ............... ............ 177
Treatment........ ..... ........... ........... 177
The Tobacco Leaf-M iner................. .......... 178
T reatm ent.... .............. ...... ..... .. ... 181
Cut-Worms ...... ....... ....... .............. 181
Habits and Life History ........... ............. 182
Appearance of a Gut-Worm ....... ............. 182
Appearance of the Moth ............ ........... 183
T reatm ent....... .......... ........... ......... 183
Grasshoppers, or Locusts..... . .... ............... 184
Bud-W orms........ ........... ........... ........ 184
D description ............ ... ........ ............. 186
Treatm ent........ .......... ..... .. ... .... 187
Spraying Apparatus ..... ............ . ............ 187















GENERAL REMARKS.




The cultivation of tobacco in Florida is an industry that is
assuming considerable proportions, and is one that will doubt-
less allow of much greater development. As usually happens,
in the extensive growing of any crop in a n'ew locality, many
previously unimportant insects become serious pests; leaving
their natural food plants, they attack the cultivated crop. and
owing to the great abundance of food, frequently develop in
enormous numbers.
To illustrate this condition, as it applies to tobacco in
Florida, we have but to mention the "suck-fly" which, previous
to the culture of tobacco, was unknown, but which has now
become one of the most serious of tobacco pests. Another illus-
tration is to be found in the Tobacco Leaf Miner, which, leaving
its natural food plant, the horse nettle, attacks the tobacco plant,
causing much damage.
One of the most important factors that enters into the suc-
cessful cultivation of tobacco, is the reduction of the ravages of
these various insect pests, and that growers are quite alive to
the importance of this matter, is evident from the interest mani-
fested in the means that may be employed to bring this about.
During the spring of 1896, a study of these tobacco insects
was undertaken by the station: although many things have in-
terfered with the extensive study then outlined, vet it has been
thought best to present the present preliminary report, in the
hope that, by its perusal, tobacco growers may become better
acquainted with their most serious insect pests, and in so far as
has yet been determined, with the best remedies against them.
It is believed that the numerous illustrations will be sufficient, in
most cases, to at once call to mind the particular insect under
discussion.














THE HORN=WORM-TOBACCO-WORM.
(Protoparce spp.)
Florida tobacco growers are doubtless quite familiar with
the horn-worm, or tobacco-worm, as it is sometimes called.
There are two species of this insect that are included under the
common name of horn-worm. These are, the Northern tobacco-
worm (Protoparce celeus) and the Southern tobacco-worm (Proto-
parce Carolina). The Southern tobacco-worm, however, is much
more common. In our insect collection, the Southern tobacco-
worm is found to be about six or seven times more abundant
than the Northern tobacco-worm. Frequent examinations in
the field, indicate that this is approximately the relative abun-
dance of the two insects. So far as the tobacco grower is con-
cerned,- however, there is but little occasion to discriminate be-
tween these two insects, as their life histories and habits are
practically the same. The Southern tobacco-worm is widely
distributed over the United States, parts of Canada, the West
Indies, and South America. In Cuba, this insect is reported as
a very severe pest to the tobacco industry. The Northern tobac-
co-worm is quite abundant in the Northern states, where in
some sections it does much damage. Its Southern limit has
not yet been accurately determined, but it is probable, that it
does not occur much further south than the United States.
These insects pass the winter in the pupa state, down in the
soil. In Florida, the adults begin to appear early in May, and
soon deposit eggs on the food plants of the larvae. Usually
this first brood is not particularly destructive, but it is the next
brood, which appears during July, that causes the most damage.
There are at least three broods of the horn-worm in Florida, and
probably a fourth, although these are sometimes not very well
marked, particularly after the July brood. An examination of
a tobacco field after this time, usually reveals horn-worms of
various sizes, in more or less abundance. The insects occur in
varying abundance as late as November, either on neglected









156
tobacco, or other food plants, as tomato. There is much varia-
tion in the severity of these insects in different localities of the
State, during the same year. Thus, in Gadsden county, the
horn-worm has been very abundant during the past season,
while at Lake City it has been comparatively scarce. Doubt-
less the July brood is the one which causes the most serious
damage to tobacco plants, and this is particularly liable to be
the case, if the May brood has been more or less neglected.
During ordinary seasons, however, the bulk of the first crop of
tobacco should have been gotten into the barn, before this
brood has had time to create much havoc. Late tobacco and
the sucker crop, however, need careful attention, to save them
from the ravages of this insect. Much damage is also done by
the horn-worm in the drying house, by being carried in on the
tobacco, where it will feed for some days. They are particularly
hard to detect under such circumstances, and care should be
taken that they are removed from the plants before they are
taken into the barn.

LIFE HISTORY AND HABITS.

SAdults, appearing from the pupa condition, soon begin to
deposit their eggs. Eggs of this insect are almost invariably de-
posited singly, and more usually, on the lower surface of the
leaves. These hatch in about three days, into very small, green
larvae, which resemble the maturer larvae in general shape.
Upon hatching, a larva eats a part or all of its egg shell, and soon
begins to feed on the tobacco leaves. Five molts are made dur-
ing the life of the larva, at different intervals. It requires about
three weeks for a larva to obtain its growth, and all this time,
it feeds voraciously on the foliage of the tobacco plant. A larva
confines itself, to some extent, to an entire leaf before attacking
another one. (see figure i) and usually those on the same side of
a plant will be eaten first. However, this varies considerably,
and a leaf may be only eaten into, and then abandoned for an-
other one. One worm would probably consume the majority of
leaves on one tobacco plant during the course of its lifetime.
From the green color of these larvae, harmonizing so well with








































































Fig. 1-Illustrating the Southern Tobacco-Worm, on remnant of tobacco
leaf. (From a photograph.)










the color of the foliage, they are rather difficult to detect. This
is, however, rendered more easy, by the abundant excrement
which they void, and which ordinarily will at once attract atten-
tion. Upon obtaining its growth, the larva enters the soil to
the depth of three or four inches, and enters the pupa state.
This condition also lasts for about three weeks, during the sum-
mer broods, at the end of which time the adult makes its appear-
ance, and is soon ready to deposit eggs. The life cycle is thus
seen to extend over a period of somewhat more than six weeks.
Since they make their first appearance early in May, and are to
be found as late as November, as many as four broods could
readily, and doubtless do, occur in this State.

DESCRIPTION.
The eggs of the Southern tobacco-worm are almost spher-
ical in shape, smooth, and are yellowish green in color, and
measure about one-twentieth of an inch in diameter. These are
quite large enough to be detected with the unaided eye.
The larva of this insect, when full grown, measures about
three or four inches in length. The head and body are dark
green, and the body is marked with lateral, oblique, white bands.
On one of the caudal segments of the worm, is a slightly curved,
horn-like process, which at one tine was erroneously thought to
be an crgan capable of producing a sting. (See figure 2.)















Fig. 2-Larva of Southern Tobacco-Worm. (From a photographh)









The pupa is illustrated
in figure 3, as it was ta- ,
ken from the soil of one
of our breeding cases. It
is a dark reddish-brown
in color, about two and
one-half inches in length,
Fig. 3-Pupa of Southern Tobacco
and is about one-fifth as Worm. (From a photograph.)
thick as long. The tongue-case projects somewhat like the han-
dle of a pitcher.
The adult of the Southern tobacco-worm is a heavy-bodied
insect, with a wing expanse of about five inches. The general
color is brownish-gray. The hind-wings are marked with two
rather indistinct angulated bands. At the base of each fore-
wing is a cluster of white spots, and on each side of the ab-
domen are five orange colored markings, bordered with black.
See figure 4, which illustrates this insect- somewhat less than
actual size.


Fig. 4--The adult (moth) of Southern Tobacco-Worm. (From a photo-
graph.)

The larva of the Northern tobacco-worm, may be dis-
tinguished from that of the Southern worm, by the eight later-
al, V-shaped markings, which seems to correspond with the
oblique lines of the latter. The pupa of the Northern tobacco-


4.i~










worm is quite similar indeed to that of the Southern tobacco-
worm. In figure 5, an adult of the Northern tobacco-worm is
















Fig. 5-The adult (moth) of Northern Tobacco-Worm. (From a phpto-
graph.)

shown, somewhat less than natural size. It will be seen by
comparison of the figures of these different insects, that they
may be readily distinguished.

TREATMENT.

From the solitary habits of this insect, it is more difficult.
to successfully control than many other species. One method
that is much used, in this and other states, is to remove the in-
sects from the plants by hand, and destroy them. This necessi-
tates going carefully over the field at frequent intervals, partic-
ularly during the time of the appearance of the broods of adults,
and carefully hunting and removing the larvae. This is a tedi-
ous and rather expensive process, but is probably one that is
mostly depended upon by the tobacco growers in this State.
Paris green has come into use to some extent against this in-
sect, particularly in Kentucky, and in certain sections of Flor-
ida. Extensive experiments made by Prof. H .Garman of the
Kentucky Agricultural Experiment Station, indicate that it is
quite practicable to treat this insect with this poison. Prof.
Garman, after making a great many tests of Paris green in










varying strengths, on both old and young larvae, sums up his
conclusions of the experiments as follows:
"I. They confirm the conclusion previously reached that
the young worms are more quickly killed than the old ones.
Thus the average duration after treatment of lots of small
worms was 4.43 days. while the treated lots of large worms per-
sisted on an average of 12.33 days.
2. The length of time required to kill worms increases as
the strength of the mixture used diminishes. The average dura--
tion of all the lots of worms, of all sizes, treated with a mixture
consisting of one pound of Paris green in 40 gallons of water
was four days, while the average for the lots which had been
treated with the mixture consisting of one pound in 150 gallons
is 14.17 days. But it must be added that the increase in the av-
erages is not a regular one, and that some of the lots treated
with weaker mixtures lasted longer than others, the worms of
which ate more of the poison. In a general way, however, the
averages show that worms of all ages fed weak mixtures live
longer than those fed strong ones.
3. When worms are young, weak mixtures will serve as
well as stronger ones. The average duration of lots of young
worms treated with mixtures varying from one pound of Paris
green in forty gallons of water to one pound in 1oo gallons was
4.11 days. The average of the lots of young worms fed mix-
tures varying in strength from one pound in 120 gallons to one
pound in 150 gallons was 4.67 days, only a trifle greater. The
increased time required to kill the worms does not consequent-
ly count against the weak mixtures used in these experiments
when the young worms are considered alone. That it is of
more importance when dealing with large worms, is shown by
the fact that the difference in average durations of lots of large
worms at the two ends of the series is much greater than in the
case of the lots of small worms. Thus large worms fed mix-
tures varying in strength from one pound in forty gallons to one
pound in Ioo gallons, persisted, on an average, 8.44 days, while
lots fed mixtures varying from one pound in 120 gallons to one
pound in 150 gallons averaged 15.25 days."
Some objections have been raised against the use of Paris








162
green on tobacco plants from the fear of injuries that are liable
to result to the user. In Bulletin No. 53 of the Kentucky Ex-
periment Station, Prof. Garman reports on the amount of ar-
senic left on tobacco sprayed with different strengths of Paris
green. This report is herewith presented as it represents the
most extensive work that has yet been done on this particular
question.

THE ARSENIC LEFT ON TOBACCO.
"The important thing to be decided is of course the quan-
tity of arsenic left on the plants at the time of cutting. \Without
giving details, I will state that if all the fluids used had alighted
on the plants and none had dripped from the leaves, there would
have been after a single spraying of July 27 on each plant of
rows I and 2 of plot I, 2.0659 grains of Paris green, and as
about fifty per cent of this was arsenic each plant would have
borne 1.0329 grain of this poison. This is a liberal estimate of
the quantity of arsenic which these plants received, for probably
not more than four-fifths of the fluid used alighted and remained
upon the plants.
On rows i and 2 of plots 2, 3 and 4, individual plants re-
ceived 4.0913 grains of Paris green in the two sprayings given
these plots, about half being applied July 27 and the remainder
August 3. Each plant is estimated to have received 2.0456
grains of arsenic.
The two rows of plot 5 treated with London purple received
4.7395 grains of London purple per plant, or 1.8957 grain of ar-
senic, considering that the London purple contained 40 per cent.
of the poison.
An examination of the report of Dr. A. M. Peter on the
chemical examination of sprayed tobacco will show that what-
ever the original quantity left on the plants, but a small part
of it remained there at the time of cutting.
The largest percentage he received by analysis was from plot
4, rows I and 2, from which arsenious oxide at the rate of .329
grains per pound of tobacco was obtained. Considering each
plant as producing 16 usable leaves and four plants as produc-
ing a pound of tobacco the poison obtained by him is the equiv-








163
alent of .0822 grains of arsenious oxide per plant. Since each
plant of these rows received in the spraying 2.0456 grains of ar-
senic it follows that on the usable part of each plant there re-
mained at cutting time only about 4 per cent. of arsenic orig-
inally applied to the plant.
The plants of plot I, sprayed but once, on July 27, retained
on usable leaves only 1.8 per cent. of the arsenic left by spray-
ing.
The arsenic recovered from plants sprayed with London
purple amounts to about 3.2 per cent of that applied.
When it is remembered that but little tobacco is swallowed
by the user it seems that the small quantitities recovered by Dr.
Peter show that spraying once or twice, as practiced by us,
would not render tobacco in any way injurious,* but I would
add that I do not think mixtures much stronger than those we
used should be employed, and that not more than three appli-
cations should be made during dry seasons.
Suppose we had used three pounds of Paris green in forty
gallons of water. With one application each plant would have
received 12.3958 grains of arsenic, and if 1.8 per cent. of this
quantity remained on the usable leaves at the time of cutting,
analysis would have recovered from one plant .2231 grain,
which is at the rate of .8924 grain per pound. If two applica-
tions of this strength had been made, calculating from the re-
sults of our experiments chemical analysis might have recov-
ered .9819 grain from the usable part of a plant, which is at the
rate of 3.9277 grains per pound of tobacco. This a large quan-
tity, and while these estimates must be considered only as ap-
proximation's they demonstrate clearly enough the general and
essential truth that a quart of Paris green in a barrel of water is
more than should be used. If last season had been very wet no
doubt less than four per cent. of the poison would have remain-
ed at the end of the season, but the part of wisdom is to avoid
such strong mixtures, since the weather cannot be safely count-
ed on to remove the excess."

"Two-thirds grains of arsenic constitute, it is said, a fatal
dose for an adult.










From the above it would appear that if properly used, no
harm should result from the application of Paris green to to-
bacco plants, but we have as yet no definite data as to the ef-
fect, if any, on the user of tobacco thus treated. There is preju-
dice, however, among buyers in some cases, against such tobac-
co. It will be remembered that there has always been more or
less of prejudice against the use of fruit and other crops protect-
ed from insects by Paris green; in many cases this prejudice
has now quite disappeared, from the fact that abundant experi-
ence has shown it to be groundless. It was noticeably so in the
case of spraying apples against the codling moth. Probably no
apple grower now believes that there is the least harm liable to
result from the use of fruit properly sprayed with Paris green.

SUMMARY AS TO THE USE OF PARIS GREEN ON
TOBACCO.

It will hardly be necessary to make more than three appli-
cations of the poison, and these should be at a time when they
will do the most good, that is, just as the young worms are. be-
ginning to make their appearance on the tobacco. In this State,
this will be during the early part, to the middle of May, the
early part of July, and the latter part of August. As before no-
ticed, however, these insects do not appear in very closely de-
fined broods, but may be present in more or less abundance in
the field, particularly after July. A close watch should be kept,
and as the worms begin to appear in considerable numbers, the
plants should be sprayed. It will probably be on the side of cau-
tion to use weak mixtures of Paris green, as one pound to 16o
gallons of water. If this is applied properly, and at the right
time, when the worms are young, it will be sufficiently strong
to kill them. It would hardly be advisable to use Paris green
stronger than one pound to 125 gallons of water and in some
cases, this proportion may perhaps be too strong. Probably
the best way to apply this would be to use a knap-sack sprayer,
the same as recommended for the treatment of the suck-fly
(figure 16). A sprayer should be purchased that has an auto-
matic agitator, so that the mixture can be kept thoroughly stir-










red during its application, thus insuring an even distribution of
the poison.

ARSENATE OF LEAD.

The arsenate of lead has also come into use to some extent
in Florida against the horn-worm. Its advantages over Paris
green are, that it is insoluble in water and hence can be used of
any desired strength without burning or spotting the foliage; it
is quite adhesive, and will remain on the foliage longer, thus ob-
viating the more frequent sprayings or dustings necessary with
Paris green; it is white in color, and is hence visible on the
foliage and thus lessens the danger from poisoning.
(n the other hand, being insoluble in water, it is slower in
poisoning than Paris green and a greater quantity is necessary.
This insecticide can probably be best applied in the form of
a powder by the use of a powder gun, such as the Standard
Duster, manufactured by Leggett Bros., 301 Pear St., New
York. The application of the powdered arsenate of lead will
give the most satisfactory results if made in the morning while
the dew is still on the leaves. A good application of the pow-
der should be effective for a week or ten days, although its ef-
fectiveness will depend much upon the absence of rain, which
washes it, to a great extent, from the plants. But since the
powder is white, it will be an easy matter to tell when it has be-
come washed off, so that other applications should be made.
No poison should be applied to the plants for the week or ten
days proceeding harvesting. During very dry weather, it might
happen that a considerable amount of the poison would still be
on the leaves, when the tobacco was ready for harvesting. Un-
der such conditions, it would be advisable to give the plants
a very thorough spraying with water, late in the evening.
It remains to speak of another means that is much used in
this State to lessen the number of horn-worms. The fight is
waged, however, against the adults, by using flowers of jimson
weed, (Datura stranionium) and sweetened water poisoned with
cobalt. Late in the evening, a quantity of the bloom of the jim-
son weed is procured, and is placed promiscuously through the
patch, in holes in horizontal slats, supported by sticks or other-










wise, and into the flower is placed, by means of a quill, a small
quantity of this poisoned mixture. This poison should be of
about the following proportions: Cobalt, one ounce; molasses,
or honey one-fourth of a pint; water, one pint. The adults in
their search for nectar frequent these flowers, and are thus poi-
soned by this mixture, which they feed upon greedily. As each
adult deposits something like 200 eggs, it is readily seen the ad-
vantage of bringing about their destruction. Many growers
cultivate the jimson weed around their tobacco fields, and her-
and there in the rows. This is advisable, and will save consid-
erable time in placing the flowers here and there in the fields.

ENEMIES OF TOBACCO-WORMS.
Fortunately, there are numerous insect enemies of tobac-
co-worms that serve greatly to keep them reduced. It is very
important that the tobacco grower should recognize these, and
foster then. Probably one of the most important enemies of
this insect in Florida is a species of Tachina fly (Sturinia sp.)
This fly lays its eggs on the outside of the larva where they
soon hatch, and the maggot works its way to the interior. Here
they feed on the tissues of the worm and, have usually about
gotten their growth, before the death of the larva occurs, as a
result of their parasitism. They enter the pupa state in little
brownish puparia within the body of the worm, and eventually
develop into flies. Figure 6 shows a larva thus parasitized, and


Fig. 6-A Taohnid parasite of To'bacco-Worms, and parasitized larva.
(From a photograph.)








G7
from which twenty-two flies were bred, in one of our breeding
cases. The fly is shown just above the larva. By careful ex-
amination, the cylindrical puparia of the fly may be seen, closely
packed together, in the body of the larva.
Another important insect enemy of the tobacco-worm is the
Apantecls congregotlls, a small hymenopterous insect. In figure
7, the larva of a near relative to the tobacco-worm is shown,
which has been parasitized by this insect. The small white
bodies on the side and back of the larva, are the cocoons of this
parasite, the grubs of which developed in the interior of the
worm and then made their exit to the outside to pupate. From
these cocoons will develop small insects which will deposit their
eggs on other larvae.












Fig. 7-Sphinx larva, parasitized by Apanteles congregatus, a common
parasite of Tobaeco-Worms. (Frcm a photograph.)
Probably most tobacco growers are familiar with the large,
reddish brown wasps which are very frequently to be seen in to-
bacco fields. This species is Polish's bd-licosus, a great friend to
the tobacco grower, as it feeds cn the young horn-worms and
other worms, and does much good in this way. There are also
several other species of Hynicnoplcra, as wasps and dirt-dobbers
that should be fostered cn account of the good they do, in de-
stroying various pests in tobacco fields.
THE SUCK-FLY.
(Dicyvplis minimus, Uhler MSS.)*
The so-called "suck-fly" of Florida is a very serious tobac-

*Kindly determined by Dr. L. O. Howard.










co pest. In fact, many tobacco growers affirm that it is the most
serious insect with which they have to contend; although it is
to be regarded as a new tobacco insect, yet it has been known
in Columbia county for the past ten years. Mr. D. L. Geer, a
prominent tobacco grower of this section, states that he has been
familiar with the insect on tobacco since 1888. at about which
time it first made its appearance. Mr. Geer also states that the
first few crops of tobacco that were planted in this section,
were not infested by the insect. Although this might seem to
indicate that it was introduced into this locality from the out-
side, yet the evidence taken collectively, does not seem to war-
rant this conclusion and it is probably to be regarded as indig-
enous, and so far as is known, is confined to Florida.
The suck-fly enjoys rather a wide distribution over the
State, and varies somewhat in abundance in the same locality,
during different years. The writer has collected this insect
from Quincy, Lake City, Lakeland. Bartow. Fort Meade and
Ybor City; so far as mv observations go, however, it seems to
be most destructive in Columbia county. In this locality, under
usual conditions, the first crop is not damaged to any serious
extent, but the sucker crop and late tobacco are frequently quite
destroyed. The insects make their appearance in injurious
numbers, usually during the first and second weeks of June, al-
though their time of appearance varies somewhat, depending on
the nature of the season. The adults are first noticed in some
restricted part of the field, as on the plants in one corner, from
which they gradually progress, as they multiply, over the field.
As their life cycle is quite short, it results that, in the course of a
few weeks, they have become quite abundant, and are distrib-
uted quite promiscuously over a considerable area. During
1897, the insects were observed in considerable abundance on
neglected tobacco as late as Nov. 22nd. This present year
(1898) several conditions seem to have contributed to their ear-
lier disappearance. They were quite scarce on the sucker crops
in various fields around Lake City by the 1st of September. At
this date, Sept. 24th, very few indeed are to be found. Accord-
ing to an observant tobacco grower in this section, "an im-
portant factor in bringing about their disappearance has been








169
the absence of rain during the latter part of August, and the
early part of September. The sticky exudation from the gland-
ular hairs of the tobacco plant causes many of these insects to
become stuck to the leaf, and in this way a great many are kill-
ed. The frequent showers keep this sticky exudation washed
off to a considerable extent, and thus favors these insects."
The suck-fly injures.tobacco by sucking from the leaf the
cell-sap, and from the fact that they occur by hundreds on a
single leaf, it is readily understood how they are able to so se-
riously damage tobacco. An infested leaf soon becomes yellow-
ish in color, somewhat wilted, and, in older leaves, eventually
splits in various places, along which a browning and drying up
occurs, so that the leaf eventually becomes very ragged.
The young of the suck-fly live mostly on the under sur-
face of the leaves. The adults may occur somewhat promiscu-
ously on the younger growth, either on the upper surface 'or
lower surface of the leaves. The adults are very partial to shade,
and may be observed feeding close out to the margin of a shad-
ow thrown by a superior leaf. A characteristic of the presence
of this insect, when abundant, is the black excrement deposited
abundantly, and most noticeable, on the lower surface of the
leaves. A leaf may become quite covered with these small
blackish spots on the lower surface. Figure 8 illustrates this
characteristic, which is from a photograph of a typical leaf, as it
appears on the lower surface. Experienced tobacco growers
say that leaves that have been badly infested with the suck-fly,
are very difficult, if not impossible, to properly cure.

LIFE HISTORY.
*.
The eggs of the suck-fly are deposited singly, in the tissues
of the leaf, mainly in the smaller veinlets. They are placed so
that the apical end is about level with the epidermis. In our
breeding experiments, the egg state was found to last for about
four days. In an egg with advanced embryo, the eyes are seen
to be distinctly reddish, so much so in fact, that it is usually
quite easy to locate an egg in a veinlet, by these reddish spots.
In hatching, the young work themselves free, and soon possess












































































Fig. 8-Showing the work of the "Suck-fly." on lower surface of tobacco
leaf. (From a photograph.)










considerable agility. In the course of three or four hours, they
have taken sufficient food, that its presence may be detected in
the alimentary canal by its greenish color. An insect grows
rapidly, and passes through five molts in all, before reaching
the adult condition. The first stage lasts about two and one-
half days, the second about two days, the third about one and
one-half days, the fourth for about two days and the fifth for
about three days. The life cycle is thus seen to extend over a
period of approximately fifteen days. During all this period,
except the egg stage, both young and adults feed voraciously
upon the plants which they infest. The number of eggs depos-
ited by adults was not ascertained. However as many as four
or five nearly mature eggs were frequently pressed from the ab-
domen of females. It is probable that they deposit, throughout
their life, a considerable number. Adults were kept alive in a
breeding cage for six days; it is probable that insects in the
field, would live somewhat longer, than under the rather abnor-
mal conditions of a breeding cage.

APPEARANCE OF THE INSECT.

The adult is illustrated in Fig. 9, enlarged about fourteen


Fig. 9-An adult "Suck-fly," enlarged 14 times.' (From a photomicro-
graph.)








172
times. It measures about one-eighth of an inch in length,
with elongated body, and rather long spindling legs; head about
as long as wide, with well developed, rounded eyes. Antennae,
five jointed, basal joint very short; third longest. Beak, four
jointed, joints sub-equal in length, the basal joint being some-
what fleshy. Tarsi, three jointed. Color of head shining black.
Thorax and dorsum of abdomen blackish, the prothorax above
with cephalic margin, and a central longitudinal stripe yellowish.
Abdomen below, greenish. Legs, yellowish-green, tarsi tipped
with dusky. Third joint of antennae, and distal two-thirds of
second, blackish.
Nyiph.-F if t h stage:
Figure Io illustrates a
full grown nymph, ,
enlarged about fourteen
times. General color of
body greenish, the legs
and antennae lighter, eyes
reddish. The two pairs of
wing-pads are about equal
in length and reach to the
middle of the second ab-
dominal segment. Anten-
nae five jointed; basal-
joint short; third and '
fourth, sub-equal. Tarsi
Fig. 10-Nymph of 'Suck-fly," enlarged
obliquely one segmented. 14 times. (From photograph.)

TREATMENT.
Various insecticides have been tried against this insect, but
it seems unusually difficult to kill. The adults, strangely
enough, are killed much more readily than the young. The
most satisfactory insecticide against this insect that we have
tried, is the "Nikoteen" manufactured by the Skabcura Dip Co.,
Union Stock Yards, Chicago, Ill. This is a very concentrated
solution of nicotine. It is claimed by the manufacturers that
the nicotine contained in one hundred and fifty pounds of to-
bacco has been extracted, and- reduced to a solution of about one










pint. By numerous tests, both in the field and laboratory, we
have found that if this is used at the rate of one part of Nikoteen
to sixty parts of water, a large proportion of the adults will be
killed, and many of the young. This solution should be applied
very thoroughly, both to the upper and lower surfaces of leaves,
with a spray pump of some sort that will throw a forcible spray.
We have found the Deming Vermorel Nozzle. (figure 17)
to be very satisfactory in the use of this insecticide. It
should be used with an elbow, so that the under surface of
leaves will be more readily sprayed. A Knapsack Sprayer, fit-
ted with a brass elbow and the Deming nozzle, would be a very
handy and serviceable combination. This could be manipulated
very easily by one man. (See spraying apparatus.)
Finding that this Nikoteen insecticide was so effective, at-
tempts were made to make a decoction of refuse tobacco leaves,
so that it would be sufficiently strong to be destructive to the
insects. It was found that to meet this requirement, it was nec-
essarv to make it at the rate of one gallon of water, to every
pound of tobacco. This should be boiled thoroughly for about
an hour, and the decoction drained off. This will have evapo-
rated somewhat during the process of boiling, but it will not be
unnecessarily strong. After straining to remove all particles of
trash that might clog the nozzle of the spraying machine, it is
ready to apply to infested plants. Owing to the various organic
compounds in this decoction, it cannot be kept more than two
or three days, in this climate, before fermentation and decom-
position will begin. Hence this decoction should not be made
until about the time it is desired to use it. Where there is a con-
siderable quantity of refuse tobacco around, as is frequently the
case, it may be more economical to prepare the insecticide in
this way, than to purchase the Nikoteen, or extract. Spraying
against the suck-fly had best be done early in the morning, as
at that time the insects are less agile, and would be more read-
ily covered with the spray. During the heat of the day, the
adults fly readily when disturbed, and hence could not be so
successfully treated at this time, as when the temperature is
somewhat lower. We have not as vet observed that the effect
of the tobacco decoction, or of the Nikoteen is injurious to to-










b cco plants upon which it has been sprayed, and everything
c nsidered, it seems to be as nearly harmless as anything we
h: ve tried.
In treating the suck-fly, a close lookout should be kept, so
that it may be detected upon its first appearance, which will
doubtless be during the early part of June, and in some restrict-
ed part of the field. As soon as it is observed to have made its
appearance, a strong effort should be made to keep it in check
as much as possible, by a thorough use of insecticides. If this
is done, the subsequent damage of these insects will be greatly
lessened. Certain measures are also to be recommended which
will serve to keep this insect much reduced in number. As soon
as a tobacco field has served its purpose, the plants should be de-
stroyed with the insects on them. This can be accomplished
very satisfactorily by pulling up the plants, and laying them in
furrows previously plowed, and covering them with the plow
as soon as possible. From this procedure it will result, that very
many of the insects will be destroyed, and their abundance an-
other year will be materially lessened. The suck-fly has been
observed during October, November and early December on to-
mato vines, and egg-plants. However, they were nothing like
so numerous as on tobacco. Diligent search has failed to re-
veal their natural food plant as yet. It is probably some solana-
ceous plant of the woods, and its discovery, and destruction
would doubtless contribute much to the extermination of the
insects.
Among some of the other insecticides tried are the follow-
ing: Whale-oil soap. This was found to be of little use against
the insects although used at the rate of one pound to four gal-
lons of water.
Kerosene emulsion was tried, of various strengths, but to
make it effective it should be used at the rate of one part of
emulsion to six parts of water. A mechanical mixture of kero-
sene and water was tried, being applied with the Deming Suc-
cess Kerosene Sprayer. This mixture was found to be destruc-
tive to most adult insects when o1 per cent. of kerosene was
used, but this amount of kerosene was very injurious to plants,
and further spraying revealed that even 5 per cent. of kero-









175
sene would severely scald the plants, even on bright sunny days.
The rose-leaf insecticide was found moderately effective
when used at the rate of one part to twenty parts of water.
Carbolic acid emulsion, and a mechanical mixture of car-
bolic acid in water, were each found to be too severe on the
plants to warrant their use against this insect.
Pyrethrum was found very effective when used in closed
vessels. When dusted on the plants in the field with a Leggett's
powder gun, many of the insects were so affected that they drop-
ped from the plants to the ground, but eventually recovered.
Pyrethrum fumes were tried and were not found successful.
Both Sulphur spray and Resin-wash were tried of different
strengths, but had little effect on the insects. Neither tobacco
nor sulphur fumes proved to be of value.
Rather late in the present season, an attempt was made to
introduce among these insects the Muscardine fungus (Sporo-
trichum globuliferuni) of the "Chinch-bug." A quantity of fung-
us was secured through the kindness of Dr. S. A. Forbes, State
Entomologist of Illinois. The inoculation experiments were be-
gun in the laboratory. Although it is too early to make any
definite statements, yet thus far, our attempts to inoculate the
insect with this disease have failed. Insects shut up in boxes,
with moistened sand on the bottom to induce growth of fungus,
were frequently observed to crawl around over the actively
growing fungus, and did not subsequently develop the disease.
From the gregarious habits of this insect, it was thought that
this fungus might be used with advantage, in its control.

CIGARETTE BEETLE.

(Lasiodcrma scricornc, Fab.)
After tobacco has been successfully grown in the field, and
has been cured and packed away in bales or boxes, it is subject
to the ravages of a small insect that frequently does much dam-
age. In fact, tobacco if left packed away for two or three years,
may become totally ruined by this small beetle. Figure 11 il-
lustrates the way in which the beetle works on stored tobacco.
This tobacco was found in a box in the Experiment Station











































































Fig. 11-Illustrating the work of the
(From a photograph.)


Cigarette Beetle on stored tobacco.











barn, and at the time it was photographed, had probably been
infested for about two years.
The insect is very abundant in Florida, infesting many
household supplies as pepper, ginger, rhubarb and similar sub-
stances. It is also reported as destructive to upholstery. It is
one of our worst pests in the Station herbarium and insect col-
lection. Both larvae and adults feed on tobacco, cigarettes
and cigars, and as they multiply rapidly during the greater part
of the year in this climate, they soon bring about the destruc-
tion of the infested material.
The insect is illustrated in figure 12, in its various stages,
all enlarged. The hair line at the right of the pupa. 1), is in-


.L)


a b c d
Fig. 12-T'he Cisarette Beetle; a, larva; b. pupa; c and d, adult. Natural
length indicated by hair line. (From F. H. Ohittenden in Bulletin No. 4, new
series, Div. of Entomology, U. S. Dept. Agri.)

tended to represent approximately the actual length. The bee-
tle is a little more than one-sixteenth of an inch in length,
brownish in color, with the prothorax and head much bent un-
der in front.
The larva is somewhat longer than the beetle, thickly cov-
ered with rather long hairs. The pupa is white, and is encased
in a delicate cocoon.

TREATMENT.

Fortunately this insect, with other insects of similar habits,
may be successfully treated. Tobacco that is found to be infest-
ed should at once be placed in large, tight boxes, and if tied up
should be loosened somewhat,and then subjected tothe fumes of
carbon bisulphide. The sulphide should be placed in a shallow
dish or pan on top of the tobacco. This chemical is highlyvolatile,


".*ti











and as the gas is heavier than air, it sinks. It is death to all in-
sect life where it becomes thoroughly permeated. Extra care
should be taken that'the boxes or receptacles of the tobacco are
exceedingly tight, and the top should be covered over, after the
sulphide is applied, by something that will keep the fumes with-
in, such as a heavy oilcloth or blanket. The quantity of sul-
phide that should be used will vary somewhat, depending upon
tightness of the box. For its use against stored grain insects
Prof. H. E. Weed has found that one pound to 100 bushels of
corn in a tight granary is sufficient to destroy grain weevils, and
other insects. Probably it will be sufficiently strong to destroy
this insect in tobacco, to use it at the rate of one ounce to every
fifty cubic feet of space in the box. It should be allowed to act
for about one day. Carbon bisulphide is harmless to the tobac-
co, and hence can be used with confidence. In its use, care
should be taken that no fire of any kind, as a lighted pipe or
cigar, be brought near it, as it is highly inflammable and might
cause serious trouble by carelessness in this way.*

THE TOBACCO LEAF-MINER.

(Gclcchia picipelis, Zetr.i
The larva of this small moth is very destructive to tobacco
in many parts of Florida. It has been known in this State as a
tobacco pest for several years, but no particular effort seems to
have been made to reduce its ravages. This has probably been
due, to a considerable extent, to the fact that its habits and life
history have not been known. The insect is not peculiar to
Florida, but occurs in many parts of the United States. So far
as present records show, however, it has not been recognized as
a tobacco pest except in Florida and in certain parts of North
Carolina. In Florida, we have found this insect feeding upon
the leaves of tomato, and upon the leaves and fruit of the egg-
plant. To the fruit of the egg-plant, it has occasioned consider-
able damage in certain parts of DeSoto county, by boring into

*For a more extended discussion of carbon bisulphide, see
Bulletin 36, p. 382, of this Station.










the fruit, thus bringing about their decay. A careful search for
the wild food plants of this insect in this locality, has failed to
reveal it, but Prof. Gerald McCarthy, formerly of the North
Carolina Experiment Station, states that its natural food plant
is Solanmn Carolincnsc, the common horse, or bull nettle, a very
common weed in North Carolina, Florida, and other Southern
States. In tobacco fields around Lake City, the larvae make
their appearance about the last of May, and may usually be
found as late as October.
These insects injure tobacco leaves, by mining, or eating
out patches of parcnchyia, or leaf tissue, from between the ep-
idermis of the upper and lower surfaces of the leaves. In this
respect, they are essentially leaf miners, although the cavity eat-
en does not resemble the linear or serpentine mines of many spe-
cies, but is a blotch mine. The result of this work is, that leaves
are rendered unfit for wrappers as they split and tear easily on
account of these numerous blotches where the 'tissue has been
eaten out. Figure 13 illustrates, from a photograph, a typical
example of a leaf infested by these larvae. From this figure it
will be seen that the eaten patches are to be found mainly along
the midrib and veinlets, for which places the larvae seem to have
a partiality. In feeding, a larva does not pass its entire life at
one place, but after eating for awhile, it will chew to the outside,
and after crawling around over the leaf, will finally enter the tis-
sue again in a new place. From this it will result, that one lar-
va on a leaf during the course of its growth, may render it quite
worthless for wrapper purposes, from the numerous blotches
eaten. A knowledge of this migrating habit is possibly of value,
as it suggests a means for treating this insect, in that it must
chew the outside of the leaf to some extent in leaving and enter-
ing the leaf, and hence might be poisoned. As a rule, the lower
five or six leaves are infested worse than those higher up on the
plant.
We have bred these insects frequently in our breeding
cages, but despite very careful scrutiny have not, as yet, been
able to find the eggs. The life cycle of this insect during the
summer is very short, usually not requiring more than twenty
days. From this it will be seen that several broods could occur


















































































Fig. 13--Illustrating work of Toj'icco Ltlf-AMiner. (From a photograph.)










during the summer. The pupa state is passed on or beneath the
soil in the neighborhood of the leaf infested. A slight cylindri-
cal cocoon is made. and in this the caterpillar changes to a pupa,
which is first of a greenish color, and later becomes brownish.
Doubtless the winter is passed both as larvae and pupae, in the
trash around tobacco fields and barns.

TREATMENT.

Doubtless the insect can be controlled to some extent by
the use of Paris green, as used against the horn-worm, and
where used thoroughly for the horn-worm, the plants should be
comparatively free from the ravages of this leaf-miner. Some
tobacco growers find it advisable to destroy these larvae by sim-
blv mashing them between the thumb and fingers, as they are
detected, by these white transparent patches in the leaf. This
can be done with considerable rapidity and will doubtless be
found quite profitable. During the winter, care should be taken
that all trash from around tobacco barns and in the fields is col-
lected and burned, thus destroying the hibernating larvae and
pupae. If this is (lone carefully, it will doubtless serve to great-
ly lessen the insects for another year. Where the bull or horse
nettle occurs, it would be well to keep a close lookout for these
weeds and when found, destroy them, thus removing the natural
food plant of the insect.

CUT-WORMS.

Under this caption are to be included the larvae of several
different species of moths belonging to the Noctuidae. The lar-
vae of these different species of moths, which are in-
jurious to tobacco, are very similar in appearance and as many
of them have practically the same habits, we may, for our pres-
ent purposes consider them as a group. From our breeding
experiments, it would seem that Agrotis epsilon is the more
common insect destructive to tobacco in this State. However.
it does not confine its attention entirely to tobacco, but attacks
various plants, as cabbage, strawberries, beans, onions, turnips,
corn and other crops. In the strawberry fields, they are fre-










quently found in great abundance. One grower reports that he
dug out on an average of 6oo daily, for a period of a week, and
finally gave up the fight. Another grower reports that he has
found as many as 40 near a single plant. These are to be re-
garded as extreme cases, for there are years when cut-worms,
like many other insects, become unusually abundant and de-
structive. To tobacco, they frequently occasion serious dam-
age, by cutting off, or chewing into the stems of the freshly
transplanted plants, so that if they do not die, they are quite lia-
ble to be blown over by the wind. The cut-worm is not con-
fined to any particular sort of soil, but occurs in greater or less
abundance in almost any locality.

HABITS AND LIFE HISTORY.

The following general statement may be made concerning
the habits and life histories of cut-worms. The eggs are deposited
by the females soon after their emergence from the pupa state,
usually quite low down, on the stems or leaves of various plants.
Upon hatching, the young larvae descend to the soil, and feed
on the tender portions of herbareous plants. They grow com-
paratively slow for caterpillars, the larvae hatched in spring,
probably becoming full grown by late fall. During the latter
part of their life, they are exceedingly voracious feeders, and
may occasion considerable damage. During mild winters larvae
of Agrotis ypsilon are to be found of various sizes, from early
fall until late spring, and it seems probable that there is but little
regularity as to the time of appearance of the adults. Many cut-
worms in this State, pass the winter either as larvae or pupae.

APPEARANCE OF A CUT-WORM.
The greasy cut-worm, the larva of Agrotis ypsilon, when
fully grown, is about an inch and a half long, with rather stout
and plump body. Its general color is brown, or a dull gray,
varying to lighter. The head is darker than the body, and is
darker above than below. The tips of the mandibles are black.
Just behind the head on the first segment, the prothorax, is a
shield, dark brown in color, and covering the dorsal surface of










this segment. There is much variation in markings, but usually
there are two pale lines extending down along the back. Along
each side, are eight small black spots, the spiricles, or breath-
ing pores. A few hairs are distributed over the body, arising
mainly from small black or brownish colored spots.

APPEARANCE OF THE MOTH.

The body and head are a little less than three-fourths of an
inch in length. From the head to the tip of the folded wings,
is about seven-eighths of an inch. The wings expand almost
two inches. Above, the insect is dark brown in general color,
and on the thorax below, whitish. On the abdomen below, it is
of a gray color, but darker on the sides. The abdomen termi-
nates in a small bunch of yellowish hairs. The fore-wings have
usually quite distinct and constant markings of lighter color.
The hind-pair are white, margined with dusky.

TREATMENT.

Probably the most satisfactory treatment for cut-worms in
tobacco fields is in the use of bran, poisoned with Paris green.
Mr. Neylands, a successful tobacco grower of Tampa, Florida,
states that he has been very successful in keeping cut-worms in
check by its use. This bait should be prepared by thoroughly
mixing Paris green with bran, at the rate of one pound of
Paris green to fifty or seventy-five pounds of bran. Just
before a quantity is to be used, it should be moistened slightly
with water sweetened with molasses. A small ring of the poi-
son should be strewn around each newly set plant, or a tea-
spoon full placed at two or three places. The cut-worms seem
to prefer this even to tobacco, of which they are inordinately
fond. Where seed beds are badly infested with cut-worms, this
poisoned bran should be drilled along in various parts of the
bed where it will be readily accessible to them. This poisoned
mixture should be renewed around the plants about every third
day, to keep it most appetizing for the larvae. Care must be
taken that it is not accessible to fowls or stock.











GRASSHOPPERS, OR LOCUSTS.
Several species of grasshoppers are injurious to tobacco.
Probably the most serious offender in this State, is the red-leg-
ged grasshopper (Pczzotettix fcmur-rubrum), although another
species of grasshopper (Pezzotettix bivilattus) is also frequently
observed chewing tobacco. During August of '97, a species of
Tettiginac was observed feeding on seedling tobacco plants at
Bartow. These seed beds were on very low soil, and conse-
quently were right in the normal habitat of this insect. The
damage by grasshoppers consists in chewing holes in the leaves,
thus destroying their value for wrappers. These insects can be
controlled to a considerable extent by the use of Paris green, as
used against the horn-worm.
BUD-WORMS.
(Heliothis spp.)
There are also two species of nearly related insects that are
referred to as "bud-worms." The larvae of these two species
are not very readily distinguished by a casual observer, nor in-
deed is it essential that they should be, since the habits of the
two are quite similar. The more common bud-worm in Florida
is the same insect that infests the cotton boll, the fruit of tomato,
and the ears of corn. It is known as the boll-worm of cotton,
Hcliothis armigcra. This pest probably needs no other introduc-
tion to tobacco growers. The other species is known as Heli-
othis rhexia, and is not nearly so abundant. Figure 14 illus-


Fig. 14-Adult of one of the Bud-Worms,
Heliothis rhexia. (From a photograph.)
trates the adult moth of this insect which was bred out, in one of










our breeding cases, from a larva found feeding on the tender
rolled up leaves in the bud of a tobacco plant. The moth is a
pretty insect, with a wing expanse of about one and a half inch-
es. The general shape of the body and wings is very similar to
that of the adult of the boll-worm. This insect, ,however, differs
considerably in color and markings. The fore-wings are of a
beautiful greenish color, obliquely crossed with three lighter
lines, which are bordered with dusky on their outer margins. A
circular discal spot, may be observed just distad of the basal
cross-bar. The hind-wings are whitish, bordered with a brown-
ish fringe. Just within this fringe, on the outer margin, is a
broad border of brownish red. The abdomen above, is some-
what rufous in color; below the insect is rather uniformly whit-
ish.
In -this State, the true boll-worm is the more serious of-
fender, and hence will receive a greater amount of attention.
It seems to prefer corn to most other crops in this and other
states, but frequently, owing to lack of this food, it infests vari-
ous plants, as cotton, tomatoes, okra, tobacco, etc. Feeding on
corn, the larvae eAt the leaves, quite riddling them with holes,
and later, when the ears begin to form, these are attacked. The
worms make their entrance, usually from the free end. Later
in the summer when the corn is "set," or has become hard, it is
not so much relished, and they frequently pass to cotton if it is
in close proximity, and attack the bolls. During the early part
of the year when these insects do not have corn or cotton to
feed upon, they are forced somewhat, to attack tobacco. Eggs
are deposited by the moths during the evening and night, on
leaves of plants on which the larvae are to feed. On the tobac-
co plant the moths place their eggs in the bud and the resulting
larvae do very serious harm by feeding on the young and yet
unrolled leaves, eating holes quite through them. Indeed a
large worm may quite devour a bud. As the leaves of the bud
grow and develop, these holes become larger, and the leaves
are thus ruined, for the best grade of tobacco. Later in the sea-
son, when the tobacco plants are fruiting, the larvae seem to
prefer the unripened capsules, to these buds. They eat holes in
the fruit, quite devouring the immature seed. Figure 15 illus-










trates one of these larvae as it was found feeding on one of these
capsules.

DESCRIPTION.

The eggs are whitish, somewhat oval in shape and sculptur-
ed with polar ribs and cross furrows.
The larva varies much in color, from a pink to quite black-
ish. The dark colored ones being found more frequently dur-
ing the latter part of the season. When full grown, a larva
measures from one and one-half, to two inches in length. (See
figure 15.)


Fig. 15-Larva of Bud-Worm, Heliothis
armigera, showing work on seed capsules
of tobacco plant. (From a photograph.)
The pupa of the boll-worm is about three-fourths of an inch
in length, and is of a polished light brown or mahogany color.
This is enclosed in a loose silken cocoon, down in the soil.










The adult is about as variable in color and markings as the
larva. In more typical specimens, the hind-wings are bordered
with a broad dark band on the outer margin, on the side of
which is usually found a white spot, varying much in size and
shape. The fore-wings are frequently bordered somewhat like
the hind-wings and marked with a spot at the centre. The
wings expand about one and one-half inches.

TREATMENT.

This pest is much more satisfactorily controlled on tobacco
than on most other crops. A very usual practice, and one that
has proven to be quite satisfactory, is to sprinkle poisoned corn-
meal in the bud. This poisoned mixture should be prepared as
follows: To a quart of finely ground cornmeal, add a half tea-
spoonful of Paris green and mix thoroughly by stirring. To
apply this, a sprinkler should be made by using a baking pow-
der can, in the lid or bottom of which, numerous holes have been
punched so that, when it is shaken, the poisoned cornmeal may
be peppered over the bud. The poison should be applied fre-
quently, and after heavy rains. In the case of large plants it may
be necessary to open the buds with the hands, and drop in a
pinch of the poison.

SPRAYING APPARATUS.

Throughout these pages frequent references have been
made to a spraying machine. For the benefit of our readers who






Fig. 17.

are unfamiliar with machinery of this kind, we illustrate in fig-
ure 16 the Success Knapsack Sprayer manufactured by the
Deming Co., Salem, Ohio. This sprayer is supplied with an








188
automatic agitator, so that in the application of insecticides or
fungicides the mixture is kept well stirred, and a more uniform
distribution thus secured. At A, in this figure, is shown a brass
elbow, which is to be attached to the hose for underspraying, as
will be necessary in spraying for the suck-fly. In Fig. 17 is illus-




















Fig. 16.

treated the Deming-Vermorel nozzle, which we have found to be
very satisfactory, as it throws an exceedingly fine spray.
Among some other manufacturers and dealers in spray
pumps should be mentioned: The Field Force Pump Co., Lock-
port, N. Y., W. B Douglass, Middletown, Conn., and William
Stahl, Quincy, Ill. A. L. QUAINTANCE.







































9I,






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