Division of Entomology and Nematology, Indian Institute of Horticultural Research, Hessaraghatta Lake P.O., Bangalore - 560 089, Karnataka, (India).
Biological control of Helicoverpa armigera (Rubn.), infesting tomato was attempted using two species of egg parasitoids, viz., Trichogramma brasiliensis (Ashm.) and T. pretiosum (Riley) under Bangalore conditions. Inundative field releases of these parasitoids were made at weekly intervals from flower initiation. A total of 2.5, and 2.5 and 5.0 lakh adults/ha were made in 5–6 releases with T. brasiliensis and T. pretiosum, respectively. Both the species of egg parasitoids at 2.5 lakh adults/ha could effectively check the population of H. armigera. The borer damage in biocontrol field was respeetively 8.92 and 7.27% as against 23.06 and 13.72% in the control when T. brasiliensis and T. pretiosum were released. Release of T. pretiosum at 5 lakh adults/ha reduced the borer damage to 1.09% as against 8.92% in the control indicating the potential of parasitolds.
