Interstructural correlations in evolution of darkling beetles of the tribe Helopini (Coleoptera: Tenebrionidae)

Various morphological structures of Helopini [sensu Nabozhenko, 2002a], their functions and evolution are considered. Some adaptations to arid environmental conditions and the main evolutionary trends in the tribe are discussed. The adaptations to digging are characteristic of Xanthomus which inhabits sandy coasts of Mediterranean. Many of Xanthomus have a digging type of fore tibiae (tibiae weakly flat, frequently with denticles and erected hairs on hide external margin.). The most part of other Helopini hide in wide hollows of ground, so some structures are adapted for movement in these hollows (epypleura, thoracic part, pronotum, body form). The genera Hedyphanes, Catomus, Physohelops have hedyphanous type of thoracic part moving in lateral and dorsoventral directions. Other groups of the tribe have nalassous type of thoracic part moving only in dorsoventral direction. Epypleura can be hedyphanous or nalassous also. Three evolutionary lines are traced in the tribe: helopious line (the subtribe Helopina), cylindronotous line (the subtribe Cylindronotina, the genera Cylindronotus, Odocnemis, Armenohelops, Reitterohelops, Stenomax) and “nalassous” line (the subtribe Cylindronotina, the genera Nalassus, Zophohelops, Turcmenohelops, Ectromopsis, Pseudoprobaticus, Stygohelops). Correlative connections between various structures Кавказский энтомол. бюллетень 1(1): 37−48 © CAUCASIAN ENTOMOLOGICAL BULL. 2005