Mined leaflets and small brown blotches on the leaf occur due to feeding on the mesophyll. The larvae web the leaflets together and feed on them, remaining within the folds. From a distance, severely attacked fields appear burnt. Drying of affected leaves and withering of plants occurs.
Damage to the groundnut is caused by leaf miner larvae. The eggs of the leaf miner are shiny white and are laid singly on the lower side of the leaflets, while the larvae are light green or brown in colour with a dark head and prothorax. The adult leaf miner is a tiny moth that measures about 6 mm in length. Its wings are brownish-gray in colour. White dots also exist on each fore wing of the adult. The larvae mine the leaves and feed inside the leaflet. They come out of the mine after 5-6 days and migrate to adjacent leaves to feed and pupate in webbed leaves. Mined areas in the leaf become dry. The leaf miners are active both in rainy and post rainy seasons, and crop losses can vary from 25% to 75%.
Conserve the natural bio-control population of spiders, long-horned grasshoppers, praying mantis, ants, ladybird beetles, crickets, among others. Intercrop groundnut with Pennisetum glaucum to enhance the parasitoid Goniozus spp. on leaf miner.
Always consider an integrated approach with preventive measures together with biological treatments, if available. Chemical sprays are only recommended when at least 5 larvae per plant at the seedling stage 30 days after emergence (DAE), or 10 larvae at flowering stage (50 DAE), and 15 larvae per plant at the pod filling stage (70 DAE) is noticed. Apply a chemical spray with dimethoate at 200-250 ml/ha (Chlorpyrifos @ 2.5 ml/l or Acephate @ 1.5 g/l) or Profenofos 20EC at 2 ml/l at between 30-45 days after sowing, if the pest populations are above the Economic Threshold Level.