Morphological Characteristics of Antennal Sensilla in Hyphantria cunea (Drury) (Lepidoptera: Erebidae)

Abstract

Fall webworm, Hyphantria cunea Drury (Lepidoptera: Erebidae) is extremely adaptable and highly invasive in China as a defoliator of ornamental and forest trees. To better understand the chemical orientation of this insect towards its host products, we determined the structure and distribution of antennal sensilla of H. cunea by scanning electron microscopy (SEM). The results showed that the male antenna was bipectinate and the female antenna was serrate, and they made of three parts, a scape, a pedicel, and a flagellum of more than 58 flagellomeres. Based on their morphology, sensilla squamiformia, sensilla basiconica, sensilla trichodea (ST1, ST2, ST3), sensilla chaetica, sensilla coeloconica, sensilla styloconica and Bohm bristles were distinguished on the antennae in both sexes. The putative functions of these sensilla also were discussed with reference to their morphology, distribution, and ultrastructure. We expect these results to help develop further electrophysiological investigations aiming to a better understanding of H. cunea olfaction.