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Group Title: Circular - University of Florida Institute of Food and Agricultural Sciences ; 379A
Title: Management of insects and related pests of ornamental plants around the home
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Permanent Link: http://ufdc.ufl.edu/UF00072572/00001
 Material Information
Title: Management of insects and related pests of ornamental plants around the home
Series Title: Circular Florida Cooperative Extension Service
Physical Description: 11 p. : ill. ; 28 cm.
Language: English
Creator: Short, D. E ( Donald Eugene ), 1935-
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville
Publication Date: 1982?
 Subjects
Subject: Insect pests -- Control -- Florida   ( lcsh )
Plants, Ornamental -- Diseases and pests -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
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Statement of Responsibility: D.E. Short.
General Note: Cover title.
Funding: Circular (Florida Cooperative Extension Service) ;
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Bibliographic ID: UF00072572
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 21005966

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HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida






. Circular 379A


Management of Insects and

Related Pests of Ornamental Plants

Around the Home


-c1


FEB 06 99


D. E. Short


University of l .'-.


FLORIDA COOPERATIVE EXTENSION SERVICE
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA, GAINESVILLE
JOHN T. WOESTE, DEAN FOR EXTENSION


ENTOMOLOGY O F
UM1wRSITY OF FLORIDA LIBRA'.IS








CONTENTS

Identification ........................................................... 3
Beneficials............................. ............................. 3
Inspecting plants ........................................................ 3

Groups of Pests...........................................................4


Control of Ornamental Pests
Non-insecticidal Control........
Chemical Control .............
Sprayers .... ................
General Purpose Sprays.........
Systemic Insecticides. ..........
Phytotoxicity-or Plant Injury ....


Specific Pests and Their Control
Sucking Pests:
Scales ...................................
Mealybugs ...............................
Aphids..................................
Whiteflies ....................... ........
Lacebugs.................................
Thrips...................................
Chewing Pests:
Caterpillars ...............................
Grasshoppers and Katydids...................
Beetles...................................
Spider Mites ................ ...............
Leafm iners .................................
Borers ................................. ....
Other Pests:
Sooty Mold .................. ...........
A nts ....................................
Millipedes, Pillbugs and Sowbugs................
Slugs and Snails ...........................


7


....U..
. ......7
........7
........7
........8


........8
...........8
.........8
.........8
........ .8


Precautions ............................................. ..... ......... 8


Important Notice

According to the Federal Insecticide, Fungicide and Rodenticide Act as amended, all pes-
ticides must be handled and applied in strict accordance with directions on the pesticide
container label. The plant and pest must be listed on the label. Also, if a pesticide is used in-
side the greenhouse, it must be labeled for greenhouse use.
To the best of our knowledge, the suggested pesticides listed herein are labeled for con-
trolling the specific pests discussed. However, pesticide labels differ widely in plant and in-
sect listings. Some are broad ornamental labels and others specifically list certain plants and
species of pests for which the pesticide is labeled. Read the label carefully.



-,4 9\ 0 Cover: Some examples of beneficial insects


1. Praying mantid
2. Assassin bug
3. Robber fly
4. Ladybeetle adult
and larva


5. Wasp parasite
cocoons on outside
of parasitized
caterpillars
6. Ant lion larva


..................
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. . . .. . .


ii


.....


. . . .

.........

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Management of Insects and Related Pests of Ornamental Plants Around the Home

D. E. Short *


To combat insect pests successfully, something
should be known about the manner in which they
develop and feed. Insects normally hatch from eggs
deposited on or near the food supply; although in
some cases, as with aphids, they hatch within the
female's body and the active young emerge from the
female. Adults usually have fully developed wings,
although a few species of insects never develop
wings.
Insects pass through several stages during their
development (metamorphosis). Plant bugs, leafhop-
pers, thrips and grasshoppers hatch from the egg in
a form known as a nymph. The nymph resembles the
full grown insect, except that it lacks wings and is
smaller. It moults periodically as it increases in size
(gradual metamorphosis). Moths, beetles and flies,

GRADUAL METAMORPHOSIS




EGG NYMPHS ADULT

on the other hand, hatch from the eggs in a worm-
like form (larva) that is much different in appearance
from the adult. The larva of a moth or butterfly is
commonly called a caterpillar; the larva of a beetle is
called a grub; and the larva of a fly is known as a
maggot. Larvae moult periodically and when ma-
ture they transform to an inactive form, known as a
pupa. The adult moth, beetle or fly emerges from the
pupa after a period of no feeding and little activity
(complete metamorphosis).


COMPLETE METAMORPHOSIS


I


EGG


LARVAE


PUPA


ADULT


The length of the life-cycle varies greatly with
many species of insects. Some develop from egg to
adult in a few days or weeks, many require a year,
and a few take two or more years to reach maturity.

IDENTIFICATION
Proper identification is very important. When the
insect is correctly identified, information regarding


its life cycle, food preference, habits and whether it
is beneficial or harmful can be looked up in various
leaflets or books available at the county cooperative
extension office or local library.


Beneficials
Less than one-half of one percent of all insects are
pests on plants. Many beneficial insects feed upon
harmful ones. Common examples of predators are
lady beetles, praying mantids, assassin bugs, am-
bush bugs, and aphid lions. Spiders also prey on
numerous insect pests. Many species of mites do not
damage plants but instead feed upon other plant
feeding mites. Also, many harmful insects are
destroyed by tiny wasp-like parasites. It is impor-
tant to learn to identify these beneficial and to
recognize when they are holding pests in check. If
such pests as aphids, scales, or whitefly nymphs
have a small hole, as if stuck by a straight pin, it is
evidence that they have been parasitized by tiny
wasps. If predators are present or the pests show
signs of parasitism, every effort should be made to
preserve the beneficial insects. Delay applying a
pesticide and allow the beneficial to control the
pest population.


Inspecting Plants
Examine your plants weekly during the spring,
summer and fall. Look at the undersides of a few
leaves on each plant and observe the stems for
pests. The use of a 10 to 15 power hand lens or
magnifying glass aids in detecting and identifying
insects and related organisms. Many insects merely
rest on the plant and are neither pests nor beneficial.
Learn to determine when a pest is present in damag-
ing numbers and to evaluate the potential of the
predator or parasite population. To aid in locating
small insects such as thrips or mites, a sheet of
white paper or cloth may be held beneath the leaves
and the foliage struck sharply. The insects or mites
will fall onto the paper and can be more easily
observed and identified than on the green foliage.
Most plants in the urban landscape are over-
sprayed, resulting in unnecessary environmental
contamination and often upsetting the natural
predator/parasite-pest balance. Don't apply a con-
trol measure until a pest population is present and
damage is beginning to occur.


*Professor-Extension Entomologist, Department of Entomology and Nematology, IFAS, University of Florida, Gainesville
32611







GROUPS OF PESTS
Pests of ornamentals may be divided into five
groups according to the way they damage plants.
Insects with Piercing-Sucking Mouthparts.
These insects have beak-like mouthparts which
are used for piercing the plant tissue and suck-
ing the plant juices.
Examples: Scales, aphids, whiteflies, mealybugs,
thrips, lacebugs, spittlebugs.
Foliage Feeding Insects. They may feed on the
leaves, flowers or attack the roots.
Examples: Caterpillars, beetles, grasshoppers,
katydids.
Spider Mites. These pests are not insects but
closely related to spiders and scorpions. They
suck plant juices with their piercing-sucking
mouthparts.
Leafminers. These are very small larvae of flies,
beetles, or moths that tunnel between the upper
and lower leaf surfaces.
Examples: Blotch leafminers and serpentine leaf-
miners.
Borers. There are many species of insects which
bore into the twigs or trunks of plants and
trees. These are either the larvae of moths or
beetles.
Examples: Pine bark beetles, seagrape borer,
carpenter worm.

CONTROL OF ORNAMENTAL PESTS
Non-Insecticidal Control
Many homeowners are able to remove some pests
and keep populations below damaging levels by
spraying their landscape plants with a forceful
stream of water. Use a garden hose with an ad-
justable nozzle and spray undersides of leaves and
stems when such pests as aphids, mealybugs,
spidermites, thrips or lacebugs appear.
Soaps are available that are formulated for con-
trolling insects and related pests. If one of the com-
mercial soaps is unavailable, two tablespoons of liq-
uid dishwashing soap per gallon of water may be ap-
plied as a foliar spray to the plants. Commercial for-
mulations of Bacillus thuringiensis (Dipel), a
bacterium, are available and provide good control of
moth and butterfly larvae. This bacteria has no ef-
fect on other groups of insects, including the
predators and parasites.
Mechanical control is sometimes practical for
small numbers of the larger insects such as cater-
pillars, grasshoppers and beetles. Frequently in-
sects can be picked or knocked off the plant and
destroyed. Large numbers of newly hatched cater-
pillars or beetle larvae may be detected by watching


for freshly skeletonized leaves and destroyed in this
way. After hatching, small caterpillars and beetle
larvae remain on the leaf for several days. Damaged
leaves can be removed and destroyed before the lar-
vae have dispersed over the plants. Early stage lub-
ber grasshoppers also feed in aggregates and can be
hand picked and destroyed.

Chemical Control
Insecticides may be required to control insects
and related pests when they reach damaging levels
on landscape plants. Most of the newer insecticides
kill by either contact with the insect or as a stomach
poison. Some also exert a fumigating or vapor ac-
tion under certain conditions.
Materials should be selected that will be effective
in controlling the pests without injuring the plant,
or causing buildup of other pests. Before using a
chemical insecticide, the following points should be
considered:'
Select the right material. Only use an insec-
ticide that is recommended to control the target
pest and is safe on the host plants.
Use the right amount. Use the recommended
amount. Too little won't control the pest; too
much may injure the plant. Read the container
label carefully for correct dosage rate.
Apply it in the right way. Thorough coverage of
the leaves (especially the underside), twigs, and
branches is essential. The insecticide spray
must reach the area of the plant where the pest
is feeding. Most failures to control pests are the
fault of incorrect application, not one of the in-
secticide. The addition of a spreader sticker to
the spray mixture is recommended when spray-
ing ornamental plants. Use of a spreader sticker
will aid in the pesticide adhering to the leaves
and improve the coverage for better control.

Sprayers
Sprayers of various types and sizes are available,
including simple trombone action sprayers, 1 to 3
gallon compressed air sprayers, and 1 to 3 gallon
knapsack sprayers. Sprayer type varies with the
size and type of planting to be protected. With all
sprayers, it is important that the leaves and wood be
covered to the point of runoff. Sprayers which at-
tach to the end of garden hoses are popular with
home gardeners. Such types are less satisfactory, in
general, for use on ornamental plants and in par-
ticular against pests like scales and spider mites.
The spray pattern is usually coarse, and it is dif-
ficult to direct the spray to reach and adequately
cover the undersides of the leaves, especially those







near the ground and on the side of plants close to a
building or fence. Considerably more insecticide is
used with the hose end attachment and this leads to
greater harm to the environment. If a hose attach-
ment is used, be sure it is one manufactured for use
on ornamental plants and not one for use on lawns.

General-Purpose Sprays
Needless to say, it is impossible to suggest one
spray mixture that will control all insect and mite
pests of ornamentals. It will often be necessary to
I ake additional treatments with other insecticides
for some pests.
An example of a general-purpose spray is one con-
taining diazinon, Metasystox-R, or malathion, plus
Sevin, in addition to Kelthane. The diazinon,
Metasystox-R, or malathion is primarily for con-
trolling sucking insects including aphids, mealy-
bugs, whiteflies, scales, and some chewing insects;
the Sevin controls a wide range of chewing insects
including beetles, caterpillars, and grasshoppers;
and Kelthane controls spider mites. General-
purpose sprays are commercially available.

Systemic Insecticides
A systemic insecticide is a chemical compound
that is absorbed by the host plant, translocated
throughout its tissues and makes the host toxic to
certain insect and mite pests. Several systemic in-
secticides are taken up from the soil by the roots of
plants and translocated throughout the plant
tissues; others can be absorbed by foliage or stem
sprays, or from injections into the plants' stems.
Systemic insecticides have been effective prima-
rily in controlling small sucking pests, including
aphids, whiteflies, scales, mealybugs, lacebugs, and
spider mites. In general, they have not given
satisfactory control of chewing insects.
Cygon, Metasystox-R, and Orthene are systemic
insecticides that are available as emulsifiable con-
centrates for use by home gardeners. They can be
mixed with water and applied as foliar sprays.
Cygon can be applied as a soil drench. Sprays give
quick kill, but the residual effect on insects is much
shorter than soil drenches. Di-Syston is available in
a 2% granular formulation and as 1% active in-
gredient in fertilizer. It is relatively slow in action,
but effective for long periods of time. Granules are
absorbed more rapidly by plants if they are worked
into the soil and watered.
Systemic insecticides applied to the soil as
drenches or granules can remain effective over six
weeks. Also, when applied in this manner, they are
relatively harmless to any insect predators and


parasites that may be present, as these insects do
not feed on the plant.
The above systemic insecticides are available in
different formulations and concentrations and the
amounts may vary for different ornamental plants.
Follow the directions and cautions on the manufac-
turer's container label for the amounts to use on the
ornamental plants specified on the label.

Phytotoxicity or Plant Injury
A pesticide or mixture of pesticides may cause in-
jury to certain plants. The condition under which
the injury occurs may vary considerably depending
upon temperature, humidity and other environmen-
tal factors. In general, it is best to apply pesticides
during the cooler part of the day. Plants are less
likely to be injured when protected by at least
broken shade as opposed to being in direct sun.
It is a good practice to water or irrigate ornamen-
tal plants one to two days before applying pesti-
cides. Some materials can injure plants when they
are stressed for moisture. Wettable powders are
generally safer to use on plants than emulsifiable
concentrates because they do not contain
emulsifiers and solvents.
Florida researchers have done extensive work con-
cerning phytotoxicity on ornamental plants. Plant
Protection Pointer #57, available from your County
Extension Office, has listings of ornamental plants
that have been damaged by various pesticides. The
pesticide label and brochure accompanying the
pesticide provide additional phytotoxicity informa-
tion for a specific pesticide.

SPECIFIC PESTS AND THEIR CONTROL
Sucking Pests
Scales
There are many different kinds of armored and
soft scales that attack ornamental plants. Most
scale insects attach themselves to their host plant
soon after hatching, and rarely do these insects
move from their feeding site during their lives. Scale
insects feed by inserting a tiny thread-like beak into
the plant and sucking the plant juices.
Scale insects are more difficult to control as they
become mature. Make weekly inspections of plants
during the spring, summer, and fall. Carefully
observe the undersides of the leaves and stems for
scale infestations. Many scale species are highly
parasitized by tiny parasitic wasps. Carefully
observe for a small hole in the wax covering which
indicates parasitism. If 20 40% have been
parasitized, continue to monitor the infestation
since a pesticide application probably is not







necessary. Egg hatching of scale insects is closely
correlated with the flush of new growth in the
spring. If plants have a history of serious, persistent
scale problems (camellia, hibiscus, holly, Ixora, etc.),
they should be sprayed in the spring shortly after
the new growth hardens and before the scales
become mature.
Cygon is a systemic insecticide that is effective
against most kinds of scale insects. Apply a second
application in 2 or 3 weeks. Metasystox-R is another
systemic insecticide that is effective against scale
insects. It is available as the active ingredient in
several trade name pesticide formulations. Apply a
second application in 2 to 3 weeks.
Diazinon, malathion and Orthene are suggested
for scale crawlers only (immediately after hatching
from the egg). Repeat the spray application in about
2 to 3 weeks. In cases of severe scale infestations a
third spray usually is needed.
Summer oil emulsion sprays may be used for scale
insect control and have very little toxicity to per-
sons handling them. In general, oil sprays are not
very effective against mealybugs.
A combination of malathion or ethion plus oil
emusion has been more effective than either
material applied alone for several scale species. In
combination the oil emulsion is used at a reduced
concentration and thus with reduced chances of in-
jury to plants. Mixtures of malathion or ethion and
oil are commercially available in many areas or they
can be mixed together according to container label.

Mealybugs
Mealybugs are important pests of annuals and
perennials in addition to some woody ornamentals.
They excrete honeydew which attracts ants and
serves as a medium for development of sooty mold
fungus.
Mealybugs are soft-bodied scale insects which are
usually covered with white powdery or cottony,
wax-like material. They vary from '/5 to 1/3 inch in
length when mature. Some of the most common host
plants for mealybugs are azalea, coleus, croton,
cacus, rose and interior foliage plants.
If infestations require an insecticide, use one sug-
gested for scales, except summer oil emulsion. Two
applications 2 to 3 weeks apart are suggested.

Aphids
Aphids or plant lice are small, soft-bodied insects
with sucking mouthparts. They usually attack
young, tender growth causing the young leaves to
curl. Their color varies from green to reddish to
black. Examine plants weekly, especially during the
spring months when new growth is abundant.
Observe for any predators or evidence of parasitism


before applying insecticides. Lady beetles and aphid
lions are important predators of these pests.
Cygon, Metasystox-R, malathion and diazinon are
recommended controls if required. A second applica-
tion is not necessary; however, keep close watch on
plants for reinfestations throughout the year.

Whiteflies
Whiteflies are common pests on many ornamental
plants. Some plants most frequently attacked in-
clude allamanda, chinaberry, citrus, fringe tree,
gardenia, ligustrum, viburnum, persimmon, and
many annuals.
Adult whiteflies resemble tiny white moths.
However, they are not closely related to moths, but
are more related to scale insects. They are only '/16
inch long and have four wings. The wings and body
are covered with a fine white powdery wax. The im-
mature stages (nymphs) which are found on the
undersides of leaves are flat, oval in outline, and
slightly smaller than a pin head. They are light
green and somewhat transparent.
Citrus whitefly nymphs, the most common whitef-
ly species attacking ornamental plants other than
citrus, are highly parasitized by a small wasp, Pro-
spaltella lahorensis. These parasites were first
released in Gainesville and Winter Haven in 1977.
In 1979, additional releases were made at approx-
imately 650 locations distributed in 65 counties.
Leaf samples received from 265 of these locations in
August-September 1980 yielded 110 positive
records for presence of the parasite and encompass-
ed 42 of Florida's 67 counties. Other survey ac-
tivities revealed presence of the parasite in five addi-
tional counties. Whitefly populations at many loca-
tions in Alachua and Polk counties have been
drastically reduced and similar reductions are ex-
pected to occur throughout the state by 1983 on all
but ornamental and commercial citrus. Citrus is the
primary host of the cloudy winged whitefly, a
species closely related to the citrus whitefly that is
not attacked by Prospaltella lahorensis.
The citrus blackfly is also under complete
biological control due to two tiny introduced wasps
which have spread throughout the state as this
whitefly has moved from its point of introduction in
Fort Lauderdale to several areas in central Florida.
Carefully examine plants susceptible to whitefly
infestations with the aid of a hand lens for evidence
of the parasite. Parasitized whitefly nymphs will
contain the larva or pupa of the parasite or the
parasite emergence hole can be seen in the whitefly
nymph (see pictures in this circular). The parasite
does not attack the adult whitefly. If parasitism is
evident, do not apply a pesticide. Chemical control







will delay increase of the parasite which will even-
tually control the pest.
If damage is evident and no parasitized nymphs
are found Cygon, malathion, diazinon, Metasystox-
R, oil emulsion and Orthene are effective controls
for whiteflies. Apply a second application in 10 to 14
days. Di-syston granules, as discussed in the
systemic insecticide section, are effective and will
not harm the parasites that may be present on
plants.
Lacebugs
Lacebugs are small insects, only about 1/s inch
long, broad and flat. Their body is usually brown in
color and the wings are clear with a fine lace-like ap-
pearance. Immature lacebugs are black, wingless,
and covered with spines. They have piercing-
sucking mouthparts and damage appears as a
whitish speckling on the top side of the leaf which is
caused by the feeding of these insects on the under-
sides of the leaves.
The presence of shiny black spots of excrement on
the undersides of leaves is a good indication of a
lacebug infestation. Some of the common host
plants are azalea, pyracantha and sycamore. Con-
trol: Diazinon, Cygon, malathion and Orthene are ef-
fective. Apply a second application in 10 to 14 days.
Thrips
Thrips are very small, slender insects with
rasping-sucking mouthparts used to remove plant
juices. Close observation is necessary to locate
them. Use hand lens and white paper as discussed
under section on examining plants. Some species,
like the greenhouse thrips and red-banded thrips,
are primarily foliage feeders. Among those that feed
on flowers are the Florida flower thrips and the
gladiolus thrips. Thrips populations are highest dur-
ing the spring months. Cygon, malathion,
Metasystox-R and Orthene are among the more ef-
fective insecticides. Apply a second application in 7
to 10 days.

Chewing Pests
Caterpillars
Numerous species of caterpillars, which are the
immature or larval stage of moths and butterflies,
feed on ornamentals. They devour the foliage, leav-
ing holes and irregular areas, or they may strip the
leaves entirely.
Bacillus thuringiensis (Dipel), diazinon, Orthene
and Sevin have been effective against most leaf-
feeding caterpillars. Dipel will control only cater-
pillars and will not harm any non-pest species pres-
ent.
Cutworms typically stay in the soil during the day
and feed at night on the base of the tender plants.


Some climb up the plant and feed on buds and
leaves. Diazinon or Dylox are effective for control-
ling cutworms. The application of a Dylox bait in
late afternoon will provide control.
Grasshoppers and Katydids
These insects occasionally consume large quan-
tities of foliage on ornamentals, leaving an ugly, ir-
regular appearance. Grasshoppers are easy to see
and should be controlled before they become
numerous. Katydids, which are green in color and
feed at night, are not commonly found in large
numbers. Frequently grasshoppers and katydids
can be removed from the plants and killed by hand.
Diazinon is an effective control.
Beetles
Beetles are hard-shelled insects with chewing
mouthparts. They feed on the foliage or flowers of
many plants. Some are active at night and hide
beneath the plant in debris or mulch during the day,
while many feed during the day. Flower beetles are
difficult to control as they often fly in from adjacent
areas in large numbers. The larvae of most beetles
are also destructive. They may feed on the roots or
bore through the stems and branches. Sevin and
diazinon are effective controls against a wide range
of beetles.

Spider Mites
Spider mites are among the most common pests
which attack ornamental plants in Florida. Home
gardeners often do not realize that mites are present
until the damage is severe, because these pests are
very small and usually go undetected on the under-
sides of the leaves.
Mites are not insects but are more closely related
to spiders and ticks. Full-grown mites are only 1/50
inch in length or smaller. The use of a hand lens or
magnifying glass and a sheet of white paper as
discussed in section on examining plants is ad-
visable when checking for their presence. They may
be light green with two dark spots on the sides of
the abdomen, red, or purplish in color. Mites feed by
inserting a tiny sucking beak into plant tissue
withdrawing plant juices and chlorophyll. This
results in a small colorless or whitish spot and in
time the leaves have a finely stippled appearance.
The most effective pesticides for controlling mites
are miticides developed especially for these pests.
Kelthane is the suggested miticide for home
gardener use. A combination spray containing
malathion plus oil emulsion as discussed for scales
will also control spider mites. Metasystox-R, Cygon
and Orthene provide some control of mites, especial-
ly when applied before populations become heavy.
Summer oil emulsion spray for use on foliage is







another old remedy that is still effective, though
thorough coverage is especially important.
Learn to recognize the mites and their injury. Ex-
amine plants at weekly intervals and treat promptly
when damage appears. Under Florida conditions,
mites are able to complete their life cycle in 7 to 10
days at 800F. Therefore, it is important to apply a
second spray application in 5 to 6 days.


Leafminers
Leafminers are the larvae of small flies, moths or
beetles that mine between the leaf surfaces. The two
most common kinds, the serpentine and the blotch
leafminers, are so-named because of the shape of
their mines in the leaves.
Leaf mining pests are difficult to control because
they are protected from insecticides by the leaf sur-
faces. Cygon and Orthene have been the most effec-
tived materials because of their systemic action.
Diazinon also offers some control. Apply a second
application in 7 to 10 days.


Borers
There are many kinds of borers, but most are the
larvae of beetles or moths. They can be placed into
three main types: (1) the pine bark beetles which
bore in the inner bark and feed on the cambium; (2)
bores which burrow in small limbs or twigs; and (3)
borers which burrow deep into the trunk. Usually
sawdust-like borings are noticed around the en-
trance holes and collect in bark crevices. Sap may
flow from holes and form small "pitch tubes."
In most cases, the borers are not the primary
cause of trouble to trees, but rather these insects at-
tack trees first weakened by something else. A tree
does not have to be badly weakened to make it
susceptible to attack by borers. Injury or stress to
the tree caused by drought, salt water intrusion, soil
added or removed above the roots, soil compaction,
digging house foundations, septic tanks, under-
ground utilities, lightning, winds, and wounds to the
trunk or roots caused by vehicles or machinery may
mark the beginning of insect problems. Also, the
setback that trees receive in transplanting increases
the possibility that borers may attack them.
Preventing borer attacks by keeping the tree or
plant healthy is the best control. Follow all ap-
proved cultural and maintenance practices, especial-
ly regarding susceptible species such as pines,
seagrapes, dogwoods, mahoganys, and oaks. If
evidence of borers is noticed, apply lindane or
Dursban as directed on container label for control.


Other Pests
Sooty Mold
Sooty mold is a black fungus that grows in the ex-
cretion of aphids, mealybugs, many soft scales, and
particularly of immature whiteflies. This fungus
detracts from the beauty of ornamental plants, but
does not cause as much injury as most people
believe. Controlling the above pests will prevent or
reduce the problem of sooty mold. Sooty mold may
be washed off with soapy water.
Ants
Ants are fond of "honeydew" excreted by aphids,
mealybugs and certain scales, and they may protect
and move these pests around from plant to plant.
They are social insects that live in colonies;
therefore, insecticides should be directed to the col-
onies or nests. Diazinon, Dursban or Sevin sprays or
Amdro bait are effective controls.
Millipedes, Pillbugs and Sowbugs
Millipedes, sowbugs, and pillbugs are not true in-
sects and are usually found in conditions where
there is plenty of soil moisture. They commonly feed
on decaying organic matter, but are also known to
feed on sprouting seeds and tender shoots of plants.
Millipedes or "thousand-legged worms" are hard-
bodied pests that are primarily a nuisance. Sowbugs
and pillbugs are about /2 inch long, oval, gray to
brown, with seven pairs of legs.
Repeated applications of Sevin or diazinon are
suggested controls for millipedes, sowbugs, and
pillbugs.
Slugs and Snails
Garden slugs and snails are not insects, but are in-
jurious to ornamental plants, especially in damp and
shady areas. They feed at night devouring foliage.
Their injury is similar to injury by caterpillars.
Slugs are soft, slimy creatures and look like snails
without shells. Recommended controls are Mesurol
bait and Metaldehyde dusts, sprays, or baits.
PRECAUTIONS
Insecticides are poisons and should be handled as
such. Read the manufacturer's label carefully before
opening the container and observe all instructions
and precautions. Wear rubber gloves and boots
when handling and applying insecticides. Avoid
breathing mists or fumes. Do not spill sprays on the
skin. Change clothes and wash all exposed parts of
the body immediately after using pesticides. Store
pesticides in original labeled containers in a locked
area out of reach of children. Rinse empty con-
tainers and put rinsings in spray tank. Dispose of
empty containers (one gallon or smaller) by wrap-
ping in newspaper, crush or puncture to prevent re-
use, and put in the garbage can for disposal in an ap-
proved sanitary land fill.








t.


A


Tea scale on camellia


False oleander scale


Florida wax scale


Parasitized white peach scale showing parasite
emergence hole


Mealybugs


4


Aphids

























Adult whiteflies


Empty whitefly nymphal case with parasite
emergence hole (right); whitefly pupa showing
normal emergence of adult whitefly (bottom);
healthy whitefly nymph (top).


Parasitized whitefly nymph (P. lahorensis larva in-
side nymph)
















La "tbOF



Lacebugs


Spidermite (greatly enlarged)


Thrips (larvae-top)























Leafminer damage


Azalea caterpillars


Sooty mold











































































This publication was promulgated at a cost of $1.298.90, or 12.9 cents per copy, to help Florida Residents
control insects and related pests of ornamental plants. 2-10M-82



COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL
SCIENCES, K. R. Tefertlller, director, In cooperation with the United States Department of Agriculture, publishes this Infor-
mation to further the purpose of the May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educa- IF
tional Information and other services only to Individuals and institutions that function without regard to race, color, sex or
national origin. Single copies of Extension publications (excluding 4-H and Youth publications) are available free to Florida
residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers Is available from
C. M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesvllle, Florida 32611. Before publicizing this
publication, editors should contact this address to determine availability.




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