COMPARATIVE MORPHOLOGY AND MOLTING OF SENSILLA-BASICONICA OF LEPISMA-SACCHARINA LINNAEUS (ZYGENTOMA, LEPISMATIDAE) AND MACHILIS SP (ARCHAEOGNATHA, MACHILIDAE)

Comparative morphological studies of the different types of sensilla b asiconica of Lepisma saccharina (Zygentoma: Lepismatidae) and Machilis sp. (Archaeognatha: Machilidae) revealed 3 types in Machilis (sensill um basiconicum types A-C) and 4 types in Lepisma (sensillum basiconicu m types D-G). No-pore sensilla (sensillum basiconicum types A, B and D ) were found in both species. The organization plan corresponds to tha t of no-pore sensilla of pterygotan insects. Original characters are d oubled basal bodies and a larger number of sense cells. L. saccharina possesses both single-walled (sensillum basiconicum types F and G) and double-walled sensilla (sensillum basiconicum type E). Machilis posse sses only single-walled sensilla (sensillum basiconicum type C). For t he first time a double-walled sensillum is described in apterygotan in sects. The sensillum basiconicum type E is a typical double-walled sen sillum but with only one circle of spoke canals near the tip of the ha ir shaft. A sensillum with spoke canals, but with a single wall, is al so found in L. saccharina (sensillum basiconicum type G). The organiza tion plan of the multiporous sensilla with pore tubules of Lepisma and Machilis corresponds to that of the multiporous sensilla of pterygota n insects. Sensillum basiconicum type F of Lepisma shows a peculiarity in that it is a ''doubled sensillum''. All sensilla basiconica descri bed in both Lepisma and Machilis have 4 enveloping cells and the posit ion of the moulting porus is at the tip of the hair shaft. (C) 1997 El sevier Science Ltd. All rights reserved.