Transcript Insect pests of tomato

PESTS OF TOMATO
Dr. Jamba Gyeltshen
7/05/10
armigera (Lepidoptera:
Noctuidae)
Host range
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tomato
peppers
okra
eggplant
beans
maize
Damage
• Feed on tomato leaves and fruit.
• Larvae may also bore into stalks or
midribs.
• When fruit is present, larvae enter it soon
after hatching. They prefer green fruit and
will enter it usually at the stem end,
causing extensive direct damage and
result in decay.
Young egg
Mature egg
Egg
• Eggs are tiny, hemispherical, and slightly
flattened on top with coarse striations or
ribs running from base to tip.
• Fruitworm eggs are laid singly on both
upper and lower surfaces of the leaves
usually in the upper part of the plant.
• When first laid they are creamy white, but
develop a reddish brown ring after 24
hours.
Young larva
Colour variation
• The young
larvae are
yellowish-white
with a brown
head and
conspicuous
black tubercles
and hairs
Management
• Monitor eggs and small larvae. Choose leaves located
below the highest open flower.
• Avoid planting tomato along with maize or near maize
fields to prevent heavy pest infestations
• Insecticides: fenvalerate, cypermethrin and chlorpyrifos.
Blister beetle (Epicauta spp)
• Blister Beetles slender gray or
black beetles
with red head,
1/2 to 3/4 inch
long.
Blister beetle damage
Blister beetle damage
Lifecycle
• The adults eat the leaves of the plants and skeletonize
the plants but the larvae feed on grasshopper eggs and
are therefore somewhat beneficial.
• They usually arrive late in the season (July-August) as
mature adults that overwintered in the soil.
• Each adult can lay 50-300 eggs in the soil which hatch
10-21 days later.
• The larvae eat and molt thru 7 stages before returning to
the soil for the winter.
• They can be hand-picked but wear gloves as they
extrude a caustic fluid in self-defense. Chemical controls
include pyrethrins and 5% Sevin.
Green peach aphid
Myzus persicae (Sulzer) (Insecta:
Hemoptera: Aphididae
Description
• Soft-bodied and pear-shaped, ranging from 1.6 to 2.4
mm long
• The wingless green peach aphid adult is pale-yellow to
green. In the fall, color may range from pale- to darkgreen to pink or red.
• The winged migrant form has a yellowish green
abdomen with a dark dorsal blotch.
• Both forms have a pair of tailpipe like appendages
known as cornicles.
• Nymphs are slightly smaller than the adult but similar in
shape. They are pale yellow-green with three, dark lines
on the abdomen.
Distribution and host range
• Cosmopolitan
• Infests a wide range of crops (tomato,
chilli, potato, tobacco, cabbage, leafy
green vegetables, legumes) and trees of
Prunus spp. (Peach, plum, nectarine)
Description of the pest
• The green peach aphid is recognized by
three longitudinal dark green stripes on the
pale green body.
Damage
• The green peach aphid has piercing sucking
mouthparts, and feeds by inserting these
mouthparts into plant tissue and sucking out the
sap.
• The aphids injures plants in three ways.
• First, feeding interferes with proper nutrient
transfer in the plant.
• Second, the green peach aphid can transmit
over 100 plant diseases, including cucumber
mosaic virus on peppers.
Damage
• Finally, aphids produce a large amount of
excrement called honey dew because of
its high sugar content. Honey dew sticks to
the leaves and often becomes a substrate
for fungus, which causes smutting of
leaves and fruit.
• Plants injured by aphid feeding will have
leaves that appear curled, distorted and
discolored.