The larval sensilla on the antennae and mouthparts of five species of Cossidae (Lepidoptera)

Abstract

Most species in the family Cossidae can migrate from one host to a new one in later larval instars, which is different from other bark- and wood-boring insects. In this study, we selected Eogystia hippophaecolus (Hua, Chou, Fang and Chen, 1990), Deserticossus artemisiae (Chou and Hua, 1986), Deserticossus arenicola (Staudinger, 1879), Yakudza vicarius (Walker, 1865), and Streltzoviella insularis (Staudinger, 1892) to understand how these species locate new hosts in their larval stages. Scanning electron microscopy (SEM) was used to determine the typology, morphology, number, and distribution of sensilla on the antennae, maxillary palps, galeas, and labial palps of these five species. There were no differences in typology, morphology, and number of sensilla between the five species. We observed antenna with three to four short sensilla basiconica, two sensilla chaetica, four sensilla basiconica, and one sensillum styloconicum. The maxillary palp had seven short sensilla basiconica, one sensillum digitiformium, and two sensilla placodea. The maxillary galea had three short sensilla basiconica, two sensilla styloconica, and one sensillum chaeticum. The labial palp had one short sensillum basiconicum and one sensillum styloconicum. Our results will provide a basis for further studies on the feeding, host-transfer behaviors, and electrophysiology of this group of forest pests.