About Tobacco caterpillar The adult moths are light brown with mottled forewings.

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.

Virtual Academy for the Semi Arid Tropics

Lesson 1: Tobacco Caterpillar Or Armyworm

Course on Insect Pests of Groundnut

Module II: Economically Important Insect Pests





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.





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.





Crop damage

The larvae feed on the foliage particularly on young leaves and buds and cause heavy damage to the foliage (Fig.).





Crop damage

They chew large areas of the leaf, and can, at high population densities, strip a crop of its leaves (Fig.).





Crop damage

The caterpillars bore into the pods particularly when groundnut is grown on light soils (Fig.).





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.





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.





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.





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.





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.





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;Monocrotophos 36 EC – 750 mL/ha

Dichlorvos 76 WSC – 750 mL/ha;Indoxacarb 14.5 SC- 250 mL/ha;Spinosad 45 SC – 125 mL/ha.

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




About Tobacco caterpillar The adult moths are light brown with mottled forewings.

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Transcript of About Tobacco caterpillar The adult moths are light brown with mottled forewings.