Comparative studies on the evolutionary patterns of microhabitats and morphology in Passalidae based on the phylogenetic analysis

金龟子科是鞘翅目的一个科，属于金龟子总科，大多数种类发生在潮湿的热带地区。它们的亚社会行为在昆虫学文献中经常被引用。它也已被称为Passalid甲虫显示出一些形态的适应性，在成年人的身体形状，他们的微生境。为了解雀形目昆虫成虫体形与小生境的关系，对雀形目昆虫8属50种进行了成虫体形的测量和小生境的野外观察。鞘翅长/体长和鞘翅宽/体长的比例在所有被研究的蜂种中是非常一致的，而体厚在属和蜂种之间有很大的差异。结果表明，较扁平的树种生活在树皮下，而前端扁平、宽的树种生活在碎屑状微生境中;东方3个雀形目属Aceraius、Macrolinus和Ophrygonius的边材/热材居群比树皮下居群的体型更凸出。由此推断，在每个属内，个体厚度的进化变化至少与微生境的进化变化相关联。

Passalidae are the family of Coleoptera, belonging to the superfamily Scarabaeoidea, and most species occur in the humid tropics. The subsocial behavior of them has often been cited in the entomological literature. It has also been known that passalid beetles show some morphological adaptations in the adult body shape to their microhabitats. In order to know the relationship between adult body shape and microhabitats, we made measurements of the adult body shape and field observations on the microhabitats for about fifty species belonging to eight genera of the Passalidae. The proportions of (elytra length)/(body length) and (elytra width)/(body length) are remarkably uniform among all the apecies examined, whereas body thickness greatly varies both among genera and apecies. We found that flatter species are living under the bark of logs and the species with flattened and widened front tibiae living in the detritus-like microhabitats.For the Oriental 3 passalid genera, Aceraius, Macrolinus and Ophrygonius, it was revealed that sapwood/heatwood inhabitants are more convex in body shape than underbark inhabitants in each examined genus. It was duduced from the present results that evolutionary change of body thickness had occurred at least once associatedwith that of microhabitat within each genus.