African Bollworm, Helicoverpa armigera

An economically important agricultural insect of cotton, tomatoes, tobacco, chickpea, maize, sorghum, wheat, groundnut, sunflower, chilli, pigeon pea.

Helicoverpa armigera or African bollworm is distributed in Asia, Africa, mainland Europe, and Australia. Russell IPM manufacture and supply pheromone lures, traps and complete monitoring systems for African ball worm, Helicoverpa armigera. Pheromone trap data gives early warning of the infestation and also exhibits the density of the insect population.

African Bollworm
Biology

Mature female can lay several thousand eggs .The eggs are approximately 0.5 mm in diameter and are white to brown in colour. Caterpillars pass through four developmental stages (instars) and ultimately reach 35 to 40 mm in length. Wavy broken lines run along the body of the cater pillar. Minute hair like spines covers the body. These are characteristic of these caterpillars. The caterpillars pupate in the soil. Pupae are usually 10-20 mm long. Adult moths have a wing-span of 30 to 40 mm, and range in colour from grey to orange-brown. The forewings have a network of dark lines and a broad brown band. The hind wings are paler, with a broad, dark brown border.

Nature of Damage

Numbers can build up rapidly, often resulting in severe crop damage caused by the feeding caterpillars. The larvae cause severe damage to reproductive and vegetative tissues of agricultural and horticultural crops. Helicoverpa armigera is the most damaging insect on cotton and legumes in Indian subcontinent. Caterpillars could may bore into flower buds, fruits, bolls or inflorescence. This habit of boring caused rotting of the fruit and leading to fruit drop. Annual losses caused by Helicoverpa  armigera alone are estimated at approximately US$5 billion on different crops worldwide (Gowda, 2005; Sharma, 2001).

Monitoring

Russell IPM manufactures and supplies pheromone lure – the Qlure, traps and complete monitoring systems for Helicoverpa armigera, African Bollworm.

Pheromone trap data gives early warning of the infestation and will also alert the user to a low level of population before it becomes serious.

The lure can be best applied with the Mothcatcher trap or Delta trap.

Lures for Pest Monitoring

Lures
Lures can be changed every 4-6 weeks to get the most accurate results.

Lures handling
Pheromone lures are a very sensitive tool. They can be affected by exposure to elevated heat and direct sunshine. Direct touching by hand may cause cross contamination leading to mixed catches in the trap. Some contaminants such as Nicotine May have repellent effect reducing trap catch.

Lure Storage
Store in a cool dry place. Shelf life can vary from 3-36 months depending on the storage temperature. See Technical Data Sheet for further details.

Trap Selection

The Deltra trap is the most sensitive trap to use for monitoring this insect. However, Moth catcher may be used in dusty conditions or in high moth population density.

Trap Density

Do not re-use the trap to monitor different insects as this may lead to mixed catches. One trap for every two hectares of large scale fields of homogenous lands.

Two traps per hectare (2trap/ha) for small holdings and in field of uneven topography.

Trap Position

Place traps near the highest point of the plant using supporting posts approximately 1 meter high, or higher if the crop is higher.

Data and Interpretation

Collect data weekly from the start of the flight of the over wintering generation. During the height of the population more frequent reading may be needed. Decisions on pesticide application should not be taken solely on the trap catch data. Climatic and biological considerations should be taken in account.