Potential of Two Trichogrammatidae species for Helicoverpa armigera control.

Helicoverpa armigera (Hübner) has attacked several economically important crops since it was first reported in Brazil in 2013. Because insecticides have been used intensively to control H. armigera, resistant populations have been detected more frequently. One alternative to insecticides is the use of biological control with egg parasitoids from the family Trichogrammatidae (Hymenoptera). The present study evaluated the use of different species and strains of these parasitoids to control H. armigera in soybean. Five strains of Trichogramma pretiosum (Riley): RV (Rio Verde, Goiás, Brazil), SO (Sorriso, Mato Grosso, Brazil), 47A (Irvine, CA, USA), PR (Colombo, Paraná, Brazil), and AN (Anhumas, São Paulo, Brazil), and Trichogrammatoidea annulata (De Santis) denominated TR, from Anhumas, were used. The following parasitoid biological parameters were evaluated: parasitism rates (%), offspring viability (%) number of parasitoids emerged per egg, egg-adult duration (days), female longevity, and offspring sex ratio. Strain RV of T. pretiosum from central Brazil performed best.