Gedanken zum “Vier-Beine-Sitzen” bei Libellen

– SOME CONSIDERATIONS ON “FOUR-LEG PERCHING” IN DRAGONFLIES – In odonates, the prdthoracal'legs serve, among other purposes, for holding prey while eating and, with the help of the specialised tibial combing spikes, they function as a “cleaning apparatus” for the head and the compound eyes. Thus, early in the hexapod evolution they have assumed the functions, which entailed that in some spp. the clasping reflex is no longer elicited during perching. Among the phylogenetically relatively young Libellulinae, the non-use of fore legs while sitting on substrate seems a general habit in Libellula and Orthetrum. Apparently, this behavioural peculiarity is to be considered a progressive feature in phylogeny. In the Zygoptera, this phenomenon has been so far recorded only in the euphaeid, Dysphaea dimidiata, which displays a perching behaviour convergent to that in Orthetrum.