Infection of Ostrinia furnacalis (Lepidoptera: Pyralidae) by Endophytic Beauveria bassiana on Corn

Abstract

The Asian corn borer, Ostrinia furnacalis Gueneé (Lepidoptera: Crambidae), is one of the most important pests of corn. Control against this pest is attempted in several ways, including the biological control with entomopathogenic fungi, Beauveria bassiana. Infection of B. bassiana in different larval phases can cause differences in insect response. This study aims to examine the effect of different larva’s stages when they are inoculated with B. bassiana to the growth of O. furnacalis. This study was conducted by allowing different larval instars of the pest to feed on corn plants inoculated with different dosages of B. bassiana spores. The observed parameters were larval mortality, pupal weight, adult longevity, adult fecundity and number of eggs and larvae infected by B. bassiana. The results showed that B. bassiana caused mortality to the 1^st and 2^nd instars of the larvae. The sub-lethal effects of B. bassiana on O. furnacalis development included reduction in pupal weight, shorter longevity, decreased fecundity of about 50% and reduced number of eggs laid up to 72.3%. B. bassiana can be transmitted vertically to the next generation. Up to 88% and 75% of the eggs and larvae were infected by the fungus, respectively.  Information provided by this study is very useful for B. bassiana conservation efforts in the corn ecosystem and for supporting integrated pest management of O. furnacalis.