Sensilla and Comparative Morphology of the Apical Segments of the Female Maxillary and Labial Palpi in the Genus Damaster (Coleoptera : Carabidae)

Sensilla on the female maxillary and labial palpi of five species of the genus Damaster were investigated with scanning electron microscopy. A total of 6 types of sensilla were observed in the apical semi-membranous area of both palpi : peg-like sensilla basiconica, cone-like sensilla basiconica types I and II, multiporous sensilla types 1 and 2, and sensilla campaniformia. No difference in the distribution pattern of sensilla between the maxillary and labial palpi were found. Based on the external morphology, each type of basiconic sensilla could be subdivided into 3, 7 or 2 subtypes, respectively. While the multiporous and campaniform sensilla were common in all the species examined, interspecific distributional variation in the subtypes of those sensilla basiconica were noticed. In addition to these results, comparative morphology of the apical segments of both palpi is discussed.