World Of Knowledge

Insect Pests Infesting Plant Foliage, Pods and Fruits. These Pests Continue Feeding on Garden Plants Throughout the Season. part-1

2009-04-26T19:39:00.004+03:00

Mexican Bean Beetle

Description: Adult - coppery-brown rounded
beetles; about 1/4 inch long, with 16 black spots on the
back. Adult spends the winter in rubbish and weeds.
Larva - yellowish, soft-bodied and fuzzy. Clusters of
yellow eggs are laid under the leaves.
Damage: Leaves appear lacy from adults and larvae
chewing on the undersides.
What to do: Apply a recommended insecticide, or
hand pick adults and larva and crush the eggs. Clean
up plant debris after harvest to reduce overwintering
adults. Plant early and pick mature pods promptly.

Stink Bug

Description: Adult is shield-shaped, flat, bright
green or brown, 5/8 inch long with wings and a narrow
head; bad-smelling when crushed. The nymph re sem -
bles adult in shape, but is somewhat more round ed than
shield-shaped, wingless, and green, orange and black.
Adults overwinter in weeds.
Damage: Adults and nymphs suck juices and cause
pods to fall and cause distortion of seeds. Brown spots
form on the pods from the feeding.
What to do: Apply a recommended insecticide;
keep the weeds down both in and around the garden.

White fly

Description: Adults - very small sucking insects
with two pairs of broadly rounded wings covered with
a snow white waxy powder. They look like tiny moths
and fly out in a cloud when disturbed. Larvae are very
small flat, scale-like insects, difficult to see. All stages
feed on the undersides of leaves and excrete honeydew.
Damage: The flies suck plant juices, causing leaf
discoloration leaf drop and stunting of plants. A sooty
mold grows on the honeydew, causing a black unsight
ly appearance on the leaves.
What to do: Use a recommended insecticide

Hornworms (Tobacco and Tomato)

Description: Large, green caterpillars with white
bars; up to 3 or 4 inches long with a slender horn projecting
from near the rear end.
Damage: Hornworms feeds on leaves, consuming
large amount of foliage. Leaf loss may result in stunting
and fruit scald.

What to do: Handpicking and destruction are often
easily accomplished because of size. If large numbers
of hornworms or plants are involved, use a rec om -
mended insecticide.

Early-Season Insect Pests

2009-04-25T20:58:00.000+03:00

Early-season insect pests infest and damage seedling
plants early in the growing season. They feed on
leaves and stems of young seedling plants.

Cutworm
Description: Plump, smooth-skinned, greasy-looking
caterpillars up to 1 inch long often found curled up
at base of plants.
Damage: Young transplants may be cut down at
ground level, or branches may be removed from larger
plants. Some damage to small tomato fruit may occur
on older plants.
What to do: Physical barriers, such as aluminum
foil wrapped around a 4-inch length of stem between
leaves and roots may be used to protect newly set
transplants. Baits, sprays or recommended insecticides
may be needed. Avoid planting tomatoes in soil
recently in grass or sod.

Thrips

Description: Adult - extremely small (1/25 inch
long), yellow or brown winged insects; very active.
Nymph - similar to adult but smaller and wingless.
Thrips often feed on weeds in and around the garden.
Damage: Adults and larvae suck plant juices and
cause whitish blotches. Tips of leaves may become
distorted and die. Entire plants may wither and fall over
with severe infestations.
What to do: Set onions should not be grown near
seed onions. Weeds in and around the garden should be
removed to reduce build-up of thrips. Beginning when
thrips are numerous enough to cause scarring of leaves,
two or three applications of a recommended insecticide
should be made at weekly intervals or as directed by
label. Certain varieties of sweet Spanish onions possess
considerable re sis tance to injury.

Flea Beetle

Description: Adult - many species; very small,
black or striped shiny beetles 1/16 to 1/8 inch long that
jump readily when disturbed. Adults overwinter under
leaves, grass and trash in and around the garden.
Damage: Adults chew tiny holes in the leaves.
What to do: Removal of weed hosts will reduce
flea beetle populations. When extremely heavy pop u -
la tions are observed on weeds surrounding the garden,
insecticide treatment of garden margins may prevent
entry by the pest. When beetles and damage are seen
on eggplant or beets, apply a recommended insecticide
before serious damage results.

Aphids
Description: Adult and nymphs - small, softbodied,
yellow, pale green or powdery grey; about
1/8 inch long with two “tail pipes.” Usually occur in
colonies or clusters on the undersides of leaves and in
broccoli heads.
Damage: Adults and nymphs suck plant juices,
leaves thicken, wrinkle and turn yellow or brown; small
plants may be severely weakened. Broccoli is very
sensitive to aphids, which are difficult to remove from
the heads in preparation for eating.
What to do: Observe small plants closely after
rapid growth begins in the spring. Wash the aphids
from the plants daily with a forceful stream of water
until the population is no longer a problem or apply a
recommended insecticide when colonies are found in
the absence of enemies such as lady beetles.

Lygus Bugs
Description: Several related species including
tarnished plant bug are included in this group. They
are flat, oval, mottled with white, yellow and black
splotch es that give it a tarnished appearance; 1/4 inch
long. When disturbed, these active insects fly or move
to opposite side of stems; they are seldom seen.
Damage: Adults and nymphs pierce and suck juices
from the pods, stems and blossoms. This feeding causes
blossoms and young pods to drop from the plants.
Feeding on the older pods causes the pods and seed to
be pitted and undesirable for food. The pods may also
be deformed.
What to do: Dust or spray with an insecticide
labeled for the specific crop. Clean up and destroy
weeds and trash in the fall to prevent overwintering.

Soil Insects

2009-04-25T20:43:00.006+03:00

Many garden insect pests live in the soil during
one or more stages of their life cycle. These insects are
adapted to feeding in or on the planted seeds, roots or
lower stems of plants.
The length of time the individual insect lives in the
soil varies from two to three weeks for some flies, to
three years for some wireworm species.
These insects may either occur as large numbers of
newly hatched larvae or as partially grown overwin
tered larvae with a ravenous appetite at the time
you plant your garden. The plants can be severely
damaged or even killed overnight following planting.
Anticipate problems with soil insects. Inspect the
plant bed soil thoroughly as you cultivate the bed.

Seed Corn Maggot

Description: Small, white maggots without legs or
a distinct head, about 1/3 inch long, that feed externally
and internally on roots and seeds.
Damage: Death of small plants may result from
maggots feeding on roots.
What to do: Avoid planting spring turnips and
radishes in soil that is high in partially decomposed
organic matter. Do not plant in wet soil.

Onion Maggot

Description: Small white maggots without legs or
distinct head, about 1/3 inch long, that bore through
underground stems and bulbs.
Damage: Thinning of stands often results from
plant death caused by the maggots tunneling in small
bulbs. Even if they are not totally destroyed in the garden,
damaged bulbs will rot in storage.
What to do: Avoid planting onions in an area high
in partially decomposed organic matter. Cull onions
should be removed from the garden after harvest.

Cabbage Maggot

Description: Yellowish white; legless larva; blunt
at the rear end and pointed at the front; about 1/4 to 1/3
inch long. The adult fly lays eggs in the soil around the
base of the plant, and the eggs hatch into maggots that
burrow down to adjacent roots.
Damage: The maggots are destructive in seed beds
and in young transplants. They feed on the roots and
stems just below the surface; seedlings wilt, turn yellow
and die. Infested cabbage rarely produces a head.
Maggots are also reported to introduce a fungus causing
blackleg and to spread bacterial soft rot.
What to do: Protect seedlings from egg-laying
adults with a square of tar paper laid flat on the ground
around the stem or cover with mesh or screen ing to
exclude the fly. Don’t plant in cold, damp soil. In the
spring, wait until the soil warms up and is sufficiently
dry. Add organic matter to the soil in the fall to reduce
soil's attractiveness to egg-laying spring cabbage
maggot flies.

Wireworm

Description: Shiny, slick, reddish-brown, tough,
6-legged worms up to 1 1/2 inches long.
Damage: The wireworm tunnels through tubers,
making deep, more or less cylindrical burrows.
What to do: Avoid planting potatoes in an area
that has been in sod for the past two or three years.

White Grub
Description: Several species. White or light yellow;
hard brown heads; curved; 1/2 inch to 1 1/2 inches
long when full grown. White grubs live in soil and are
larvae of May and June beetles. They require three
years to mature. Adult lays eggs in grassy areas.

Potato Tuberworm
Description: White caterpillars up to 3/4 inch long
with a pinkish or greenish tinge and brown at both
ends.
Damage: Larvae burrow into stems and petioles
and mine the leaves of plants. The tubers of potatoes in
the field and in storage are riddled with slender, dirtylooking,
silk-lined burrows.
What to do: Keep potatoes well cultivated and
deeply buried in hills during growth. Infested vines
should be removed before digging to avoid larval
movement to tubers.

Insect Reproduction,Growth and Development

2009-04-20T22:48:00.004+03:00

How Insects Grow

Most insects develop from an egg and, upon
hatching, have a form different from that of the adult.
The series of form changes as an insect develops from
egg to adult is called metamorphosis. The young
insect is covered with a more or less firm skin called
the exoskeleton. As the insect feeds, it grows inside
this skin, but it cannot increase in volume because it is
restricted by its exoskeleton. A new elastic exoskeleton
then forms under the old rigid exoskeleton. The old
exoskeleton splits along the back and the insect crawls
out of its old skin and expands to its new size. After
exposure to air for a short time, the new exoskeleton
becomes hardened and the insect is ready to resume
activity and grow some more. The process of shedding
the old skin is called molting. Molting occurs several
times over varying periods of time until the final stage
is reached.
With each molt insects change their form to varying
degrees, depending on the kind of metamorphosis
that insects may have. Most vegetable garden insect
pests have either gradual (Figure 1) or complete
metamorphosis (Figure 2). Ex am ples of gradual or
incomplete metemorphosis, in which the very young
resemble the adults, include plantbugs, grasshoppers,
stink bugs, squash bugs, aphids and leafhoppers.
Examples of pests with com plete metamorphosis are
Mexican bean beetles, cab bage loopers, hornworms,
flies, June beetles, cutworms and armyworms.

Gradual metamorphosis

(Figure 1). Generally
these young insects resemble the adults. In proportion
to the rest of the body, the legs and head become relatively
smaller in each instar. This is because the head
and legs do not grow as fast as the rest of the body.
In insects which are winged, there is also a gradual
development of the wings with each molt. There are
no more molts after the fully developed, winged, adult
emerges. Not all of these insects develop wings. The
young are called nymphs. Nymphs and adults inhabit
the same places and eat the same kind of food.

Complete metamorphosis

(Figure 2). All four

stages of development - egg, larva, pupa and adult - are
present. All increases in size occur during the larval
stage. Some people erroneously think that small flies
will grow to be big flies. At the end of the larval stage,
the insect transforms into a pupa which does not feed
or move about. It is sometimes called a resting stage,
but inside the pupal skin drastic changes are taking
place. More alteration of form is going on during the
pupal stage than during any other period of the insect’s
development. Out of the pupa emerges the fully formed
adult, complete with wings. No further molts occur.
The larvae and adults of these insects may live in
different habitats, eat different food, have different
kinds of mouthparts and have many other differences.
The larval stage of some orders of insects are called
maggots, grubs or caterpillars.

Insect Infestations

2009-04-20T22:44:00.001+03:00

Insect infestations reduce yields and lower the
quality of harvested garden vegetables. Three to seven
gen er a tions of many insect pests attack garden
veg e ta bles during the growing season. All plant parts
may be injured by insects. Some insects bore into roots,
seeds or stems. Many suck large quantities of plant
sap. Others destroy crops by chewing on the succulent
foliage, stems or fruits. Plant diseases are carried by
certain insects.
Safe, effective and economical control measures
can minimize the loss from insects. Control can be
main tained all season by a combination of cultural
practices, mechanical control, biological control and
chemical applications. To maintain control, follow
these practices, as they apply to the vegetables in your
garden:
• Anticipate insect pest problems.
• Remove other vegetation and debris that harbor
insects from vegetable garden beds.
• Turn under spent plants when the vegetables have
been harvested.
• Inspect plants regularly for insect infestations and
spray when needed.
• Apply sprays when the young, most vul ner a ble stages
of insect pests are beginning to hatch or emerge.
• Observe use restrictions and avoid applying insecticide
on garden vegetables within the minimum
number of days between last ap pli ca tion and harvest.
• Select insecticides that take a short time to control
insects during the harvest period.

Sweet Gum

2009-04-20T19:53:00.002+03:00

Liquidambar styraciflua
Notes
Star-shaped leaves turning red to purple in autumn; female flower forms the hard,
spiny gum balls that encase the seeds. Cultivars suitable for Kentucky include Festival
and Rotundiloba

Walnuts

2009-04-20T19:50:00.003+03:00

Walnuts
Juglans spp.
J. cinerea (butternut, white walnut)
J. nigra (black walnut)
Notes
Butternuts are not recommended except in the mountains
at high elevations because they are susceptible to
bacterial canker that results in a short-lived tree, usually
fewer than 20 years; self-fruitful, although they perform
better when cross pollinated. Cultivars recommended for
Kentucky include Clermont, Emma K, Farrington,
Myers, Sparrow, and Stabler. Extension horticulturalists
do not recommend planting black walnut because it is
the last to produce leaves in the spring, first to drop leaves
in the fall, the nuts are messy, and there is juglone toxicity
to other plants. Larval food for banded hairstreak
butterfly. Squirrels love these nuts!

Ash

2009-04-20T19:47:00.001+03:00

Ash
Fraxinus spp.
F. americana (white)
F. pennsylvanica (green)
F. quadrangulata (blue)
F. profunda (pumpkin)
Notes
Medium-sized tree; opposite leaf arrangement; winged
seeds; brilliant yellow fall foliage for green ash and red to
maroon color for white ash; grows best in full sunlight.
Cultivars of green ash suitable for Kentucky include
Bergeson, Emerald, Newport, Patmor, Summit, and Urbanite.
Cultivars of white ash suitable for Kentucky include
Autumn Purple, Autumn Applause, Champaign
County, Rosehill, and Skyline. Extension horticulturalists
do not recommend green ash because of storm damage
problems. Larval food for tiger swallowtail, hickory hairstreak,
and mourning cloak butterflies

Beech

2009-04-20T19:45:00.001+03:00

Beech
Fagus grandifolia (American)
Notes
Retains brown fall foliage through the winter; threeangled
nuts; shade tolerant. Squirrels love this nut. Larval
food for early hairstreak butterfly.

Persimmon

2009-04-20T19:43:00.001+03:00

Persimmon
Diospyros virginiana (common)
Notes
Orange fruits ripening in fall can be eaten by humans; red to
yellow fall foliage; common along the edges of woodlands,
old fields, and fencerows. The sexes are separate, and both
male and female trees must be present to obtain fruit. Deer,
turkeys, raccoons, and squirrels love these large fruits.

Hackberry

2009-04-20T19:41:00.001+03:00

Hackberry
Celtis spp.
C. laevigata (sugarberry, smooth hackberry)
C. occidentalis (common)
C. tennuifolia (dwarf)
Notes
Gray to brown warty bark; small red fruits when ripe; unattractive light
yellow fall foliage; common along fencerows, roadsides, and old fields.
Larval food for snout, question mark, mourning cloak, tawny emperor,
and hackberry butterflies. Extension horticulturalists do not recommend
planting common hackberry because it reseeds and has a witch’s broom
type of growth

Catalpa

2009-04-20T19:38:00.002+03:00

Catalpa
Catalpa speciosa (northern catalpa, cigar tree)
Notes
Larval food for tiger swallowtail butterfly; flowers are
used as a nectar source by hummingbirds.

Hickories

2009-04-20T19:25:00.001+03:00

Carya spp.
C. aquatica (water)
C. glabra (pignut)
C. illinoensis (pecan)
C. laciniosa (big shagbark, big shellbark, kingnut)
C. ovalis (sweet pignut, small-fruited)
C. ovata (shagbark, shellbark)
C. tomentosa (mockernut, white)
Notes
Shagbark, pecan, big shagbark, pale, and sweet pignut have
edible nuts; subject to disease; slow growing; nuts can be selffruitful
in some cases, but allowing for cross pollination is
better. Varieties of shagbark hickory recommended for Kentucky
include Yoder #1, Bridewater, Silvas, Wurth, Grainger, Wilcox, Porter, and Wilmoth. Varieties
of shellbark recommended for Kentucky include Fayette, Bradley, Chetopa, Keystone, Lindauer,
Neilson, Stauffer, Stephens, and Totten. Varieties of pecans recommended for Kentucky include
Chickasaw, Fisher, Greenriver, Hodge, Kentucky, Major, Mohawk, Posey, and Shoshone. Larval
food for hickory hairstreak and banded hairstreak butterflies. Squirrels love these nuts!

Buckeyes

2009-04-20T19:21:00.002+03:00

Aesculus spp.
A. discolor (red and yellow)
A. glabra (Ohio)
A. octandra (yellow, sweet)
A. pavia (red)
Notes
Flowers are used as a nectar source by hummingbirds.
One of the first species to produce leaves
in spring. No exceptional fall color.

Acer spp

2009-04-19T20:05:00.000+03:00

Maple

Acer spp.

A. nigrum (black)
A. negundo (box elder)
A. pensylvanicum (striped)
A. rubrum (red)
A. saccharinum (silver, water)
A. saccharum (sugar)

Notes

Opposite leaf arrangement; distinctive
winged seeds called samaras;
brilliant orange to red fall
foliage in sugar, black, and red
maples; grows best in full sun to
partial shade. Cultivars of red
maple suitable for Kentucky include
Armstrong, Autumn Flame,
Bowhall, Columnare, Edna Davis,
Gerling, Karpick, Northwood,
October Glory, Red Skin, and Red Sunset. Cultivars of sugar maple suitable for Kentucky
include Bonfire, Caddo, Commemoration, Columnare, Green Mountain, Legacy, Steeple,
and Sweet Shadow. Silver or water maple is not recommended because it has been
overplanted in the landscape, reseeds, is weak-wooded, trashy, and self-destructs in ice and
wind storms.