We evaluated possible improvements to the mass rearing of the larval parasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) on irradiated host wax moth Galleria mellonella L. and Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larvae. The use of irradiated G. mellonella and P. interpunctella larvae at the dose of 150 Gy proved useful for enhancing the parasitism and adult emergence of H. hebetor due to the absence of negative repercussions on parasitoid development. Overall, parasitism was increased as the host larvae was irradiated with higher doses, while significantly higher parasitism was recorded at 150 and 300 Gy compared to lower doses. The female parasitoids preferred the irradiated larvae and significantly higher numbers of larvae were parasitized compared with non-irradiated larvae. The results also showed that irradiated larvae of G. mellonella served better as hosts for H. hebetor as compared with irradiated larvae of P. interpunctella. The implementation of these findings would be helpful for improving the mass production of parasitoids and the effectiveness of releases of biocontrol agents for the control of stored product pests.
Keywords: Galleria melonella; Habrobracon hebetor; Plodia interpunctella; biological control; gamma irradiation; parasitism.