Pathogenicity of Beauveria bassiana to fall webworm (Hyphan­tria cunea) (Lepidoptera: Arctiidae) on different host plants

A study on the compatibility of the entomopathogenic fungus Beauveria bassiana with two medicinal plants, Artemisia annua (0.5%) and Lavandula stoechas (0.6%), was conducted against fall webworm, Hyphantria cunea, in the presence of three host plants including plane tree (Platanus orientalis), boxelder (Acer negundo), and mulberry (Morus alba). The highest concentration of B. bassiana yielded the highest H. cunea mortality in all three host plants. The combination of B. bassiana and plant extracts caused the highest H. cunea mortality in all host plants. The difference could be attributed to the nutritional effects of host plants on total physiological status of larvae. To prove this point, the digestive enzymatic assessments were studied and it was pointed out that a statistical difference of α-amylase, protease, and lipase activities exists among larvae feeding upon different host plants. Thus, a combined application of an entomopathogenic fungus and a botanical insecticide may be beneficial for the control of H. cunea.