Module II: Economically Important Insect Pests Virtual

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Module II Economically Important Insect Pests
Virtual Academy for the Semi Arid Tropics
Lesson 1 Tobacco Caterpillar Or Armyworm
About Tobacco caterpillar The adult moths are
light brown with mottled forewings.
Eggs are laid in clusters of several hundreds,
usually on the upper surface of leaves and
covered with scales.
Course on Insect Pests of Groundnut
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About Tobacco caterpillar The caterpillars are
light green. As they grow, they become dark green
to brown on their backs, lighter underneath, and
have prominent black spots (Fig.) near the mouth
region.
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Newly hatched caterpillars can be detected by the
'scratch' marks they make on the leaf surface
(Fig.). The older ones are night-feeders and
are usually found in the soil around the base of
plants during the day.
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Crop damage The larvae feed on the foliage
particularly on young leaves and buds and cause
heavy damage to the foliage (Fig.).
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Crop damage They chew large areas of the leaf,
and can, at high population densities, strip a
crop of its leaves (Fig.).
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Crop damage The caterpillars bore into the pods
particularly when groundnut is grown on light
soils (Fig.).
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Management During the first 50 days of the crop
if the defoliation is over 25, or if more than
one larva (fourth instar and above) per plant is
observed, then only one should initiate the
recommended plant protection measures.
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Management Set up pheromone traps at 2 traps/ha
to monitor the adult (moth) populations. Grow
castor or sunflower along the border and
irrigation channels as an indicator or trap
crop. Collect the gregarious early stages
caterpillars in clusters (which manifest the
lace-like leaves by their feeding) on castor or
sunflower and destroy them.
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Management Avoid migration of caterpillars by
digging a trench 30 cm deep and 25 cm wide with
perpendicular sides around the infested
fields. Apply nuclear polyhedrosis virus (NPV)
at 250 LE (larval equivalents)/ha with sugar 2.5
kg/ha in the evening hours. Sugar acts as a
sticker and as a stimulant.
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Management Prepare bait with the following
materials to cover one hectare. Rice bran 12.5
kg, molasses 2.5 kg or 1 kg of jaggery, and
Carbaryl 50 WP 1.25 kg/Monocrotophos 36EC 200
ml/Quinolphos 1 liter. Mix the ingredients to a
homogeneous mixture, sprinkle water gradually and
bring the bait to a dough consistency.
Distribute the above bait on the soil, around
the field and inside in the evening hours
immediately after preparation. This is mostly
practiced in irrigated and high-input-use areas.
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Management A number of recommended pesticides
are available to control the pest. But, the
farmers are advised to select the pesticide which
is selective and environment friendly among the
recommended chemical.
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Management Apply any one of the following
insecticides to control early stages of
caterpillar Carbaryl 10 D-25 kg/ha
Carbaryl 50 WP 2.0 kg/ha Quinolphos 20 EC-750
mL/ha Endosulfan 35 EC- 1.0 liter/ha Monocrot
ophos 36 EC 750 mL/ha Dichlorvos 76 WSC 750
mL/ha Indoxacarb 14.5 SC- 250 mL/ha Spinosad
45 SC 125 mL/ha.
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Module II Economically Important Insect Pests
Virtual Academy for the Semi Arid Tropics
The Lesson 1 on Tobacco caterpillar
concludes. The Lesson 2 is about Hairy
caterpillars affecting groundnut crop. The
subsequent Lessons describe other economically
important insect pests in groundnut crop. Select
Lesson 2 in Module II from Course contents
Course on Insect Pests of Groundnut