Mouthpart sensilla of cave species of Australian Paratemnopteryx cockroaches (Blattaria : Blattellidae)

The external morphology and distribution of sensilla on maxillary and labia l palpi are described for 3 Australian cave-dwelling cockroach species, Par atemnopteryx stonei, P. howarthi, and P. sp. nov (Blattaria: Blattellidae), using scanning electron microscopy. The apex of the maxillary palpus expan ds ventrally into a flexible pad with a distinct sensillar field. The total number of sensilla ranges from 1045 (males)-1486 (females). Sensillar fiel ds of females are larger and contain more sensilla than those of the males, although the density of sensilla is usually equal or greater for males. Pa pilla-like groove-and-slit chemoreceptors comprise 93-97% of the sensilla. Two types of trichoid sensilla occur along with bifurcuted sensilla and rar e basiconic sensilla that are poreless and have an inflexible socket. Chaet ic sensilla occur on all species and several thousand pectinate scares, wit h bulbous bases, and spicules are present in large fields on each side of t he sensillar field. The apex of the labial palpus is only slightly expanded into a sensillar field. Sensillar diversity is similar to the maxillary pa lpus but there are only 5-29% as many sensilla, the number ranging from 97 (mares)-346 (females). Sensillar fields of females are slightly to much lar ger than those of males but the sensillar density is equal between the sexe s or greater on males. Two types of trichoid and one or two types of basico nic sensilla occur on each species. Chaetic chemoreceptors are present alon g with three types of nonsocket spines. Sensilla varied moderately in morph ology and gender-related abundance from those on epigean cockroach species. (C) 1998 Elsevier Science Ltd. All rights reserved.