Dorsolateral cuticular outgrowths in second stadium larvae ofGomphus flavipes(Odonata: Gomphidae)

Abstract

Second and third stadium larvae of Gomphus flavipes have dorsolateral cuticular outgrowths in the form of small basal tubercles bearing fan-shaped setae. These sensilla are aligned in two rows on each side of the thorax and abdomen. European species of Gomphus, Onychogomphus and Ophiogomphus that we examined lack these structures, having instead, at most, short hairlike setae in double rows. The fan-shaped setae of G. flavipes are present only in second and third stadia, apparently being lost later in larval development. We speculate that this loss might be due to changes in microhabitat or might be some kind of phylogenetic constraint.