Bouchard P, Gorb S N
Department of Zoology and Entomology, University of Queensland, Brisbane, Queensland 4072, Australia.
Arthropod Struct Dev. 2000;29(4):323-31. doi: 10.1016/s1467-8039(01)00013-5.
The elytra-to-body binding mechanism of the flightless rainforest species Tabarus montanus Kaszab (Coleoptera: Tenebrionidea) is described. Previously, studies on this complex character system in tenebrionids have focused mostly on either fully-winged or flightless, desert-dwelling species with a hermetically sealed subelytral cavity. Data presented here show that the rainforest species Ta. montanus has permanently joined interlocking macrostructures between the two elytra along the midline and between the elytral epipleuron and the sides of the body. These are very similar adaptations to ones found in flightless desert tenebrionids. Frictional patches of microtrichia, previously reported in all wing-folding beetle suborders including flightless taxa, are completely absent in Ta. montanus. This constitutes the first report of the complete loss of frictional microtrichia patches in a beetle with fully-developed elytra. Sensory organs (hair sensilla), usually involved in the correct positioning of the elytra over the beetles' body at rest are also absent in Ta. montanus. The significance of these results relating to the evolution of the tenebrionid subelytral cavity is discussed.
描述了无翅雨林物种山地扁甲（Tabarus montanus Kaszab，鞘翅目：拟步甲科）鞘翅与身体的结合机制。此前，对拟步甲科这一复杂特征系统的研究主要集中在具有完全翅膀或无翅、栖息于沙漠且具有密封的鞘翅下腔的物种上。此处呈现的数据表明，雨林物种山地扁甲在两个鞘翅之间沿着中线以及在鞘翅缘折与身体侧面之间具有永久相连的互锁宏观结构。这些与在无翅沙漠拟步甲中发现的结构非常相似。在山地扁甲中完全没有此前在包括无翅类群在内的所有翅折叠甲虫亚目中都有报道的微刚毛摩擦斑块。这是关于具有完全发育鞘翅的甲虫中摩擦微刚毛斑块完全缺失的首次报道。在山地扁甲中也不存在通常参与鞘翅在甲虫静止时于身体上正确定位的感觉器官（毛形感器）。讨论了这些结果与拟步甲科鞘翅下腔进化的相关性。
