African bollworm on French beans. Fully grown caterpillars are 3-4 cm long.

African bollworm eggs are tiny (diameter 0.4-0.6 mm), yellowish-white and glistening at first, changing to dark-brown before hatching; pomegranate-shaped.

African bollworm caterpillar (larva) is initially pale green, sometimes with black dots, and a pattern of thin dark lines running along the body, the lines being darker around the second and third segments. In later instars, the dark lines become less conspicuous, and the black spots develop red areas around them. There is a good deal of variation in colour in this species. Lighter and darker forms of both caterpillars and moths are known, for example, having white instead of black spots on the caterpillars. The caterpillar postures when disturbed characteristic of a number of species in this family: it lifts its head and curls it under the front of the body. If even more disturbed, it lets go and drops, rolling into a spiral. Fully grown caterpillars are 3 to 4cm long.

African bollworm caterpillar (3-4 cm long) feeding on French beans

African bollworm caterpillar (3-4cm long) feeding on French beans. Note posturing of the caterpillar (it lifts its head and curls it under the front of the body).

African bollworm feeding on flower of French beans (3-4 cm long)

African bollworm caterpillar (3-4cm long) feeding on French bean flower.

Damage by African bollworm on French beans. Note faeces next to the caterpillar.

Young caterpillar of African bollworm feeding on okra leaf and adult moth (inset).

African bollworm feeding on peas

African bollworm feeding on okra

The African bollworm pupa is shiny brown, about 16 mm long

Adult moths of African bollworm are about 14 to 18 mm long with a wingspan of 35 to 40 mm.

African bollworm damage in chilli fruit