There are different coloured larvae known as fruit borer infesting tomato crop at its reproductive stage. One larva can damage more than one fruits. On initiation, spray any biopesticides like Bouveria. If this pesticide does not give a satisfactory result, spray chlorantraniliprole 18.5 SC @ 3 ml or flubendiamide 20 WG @ 5 g or novaluron 10 EC @ 10 ml or chlorantraniliprole 8.8% + thiamethoxam 17.5% SC @ 10 ml per 10 lit of water. On each spray, change the insecticide formulation.