Ecofriendly Managing of Helicoverpa Armigera in Tomato Field By Releasing Trichogramma Evanescence and Habrobracon Hebetor

Health and environmental side effects of chemical insecticides and development of resistant population of helicoverpa armigera hubner (lepidoptera: noctuidae) to pesticides have resulted in increasing demands for non-chemical control approaches against this pest. in this research, the efficacy of two biological control agents were studied under field condition. treatments consisted of releasing habrobracon hebetor (say) (hymenoptera: braconidae), trichogramma evanescence westwood (hymenoptera: trichogrammatidae) and combination of h. hebetor + t. evanescence (habrobracon-trico). the results revealed significant differences in the number of infested tomato fruits among treatments and harvesting times. the infested fruits was the lowest (2.68 ± 0.14%) in plots treated by habrobracon-trico. moreover, the highest (3.36 ± 0.50%) and the lowest (2.88 ± 0.22%) damaged fruits was recorded in the second and fourth harvesting times, respectively. there was significant interaction between harvesting times and treatments. regarding the tomato yield in treatments, findings revealed significant difference among treatments in both main harvesting times. however, there was no significant differences in total yield in treatments. it could be concluded that biological control agents can be used as a promising alternative for synthetic insecticides in control of h. armigera in tomato farms without significant crop losses.