What are the damage symptoms of groundnut aphid?

This is one of the most serious pests of groundnut. The nymphs and adults suck the sap, usually from the underside of leaves. Infestation in the early stages causes stunting of the plants as well as reducing their vigour.  When the attack occurs at the time of flowering and pod formation, the yield is reduced considerably. Infestation on the groundnut crop usually occurs 4-6 weeks after sowing. The aphid is also vector of rosette disease of groundnut.