Susceptibility of the Hymenopteran Parasitoid, Habrobracon hebetor (Say) (Braconidae) to the Entomopathogenic Fungi Beauveria bassiana Vuillemin and Metarhizium anisopliae Sorokin

Habrobracon hebetor (Say) is an ectoparasitoid and has been studied as a biocontrol agent of various lepidopteran pests such as cotton bollworm Helicoverpa armigera (Hübner). With regards to the negative effects of common pesticides used in cotton fields on the parasitoids, in this study the effects of different isolates of entomopathogenic fungi (Beauveria bassiana and Metarhizium anisopliae) were evaluated on H. hebetor. Bioassay experiments were performed by the immersion method. For each of the treatments 15 immature individuals of the parasitoid were used. After recording the results, data were analyzed using SAS software. Bioassay results of fungi isolates on larval stages showed that the value of LC50 for IRAN187C isolate of B. bassiana was 1.46 × 109 conidia/ml. Because of the low mortality caused by the other isolates, the value of LC50 was not set for them. Also, bioassay of fungal isolates showed that none of the isolates had any effect on the parasitoids pupal stage. According to the obtained results, it can be concluded that various fungal isolates of B. bassiana and M. anisopliae had little adverse impact on the parasitoid wasp, thus after doing field tests, the microbial control agents may be used along with these parasitoids in integrated pest management programs (IPM) in cotton