Morphology of the last instar larvae of Sceliphron asiaticum (Linnaeus, 1758) and S. fistularium (Dahlbom, 1843), with a review on larval characters in Sceliphrinae (Hymenoptera: Sphecidae)

Abstract

Sceliphron is a cosmopolitan genus of mud-dauber spider-hunting solitary wasps with 35 species. Although the taxonomy of this genus is relatively well understood, the larval morphology is still poorly known. In the present paper the last instar larvae of Sceliphron asiaticum (Linnaeus, 1758) and Sceliphron fistularium (Dahlbom, 1843) are described, based on specimens collected from natural nests in Brazil. Both optical and scanning electronic microscopes are used. Some larval characters useful for the systematics of the subfamily Sceliphrinae are reviewed, namely shape of the head, rugosity on the top and sides of the head, shape of the mandibles, papillae on spinnerets, size of setae on the head, length of the labial palpi and galeae and body colour. A summary of literature data on morphometric features of larval Sceliphrinae is also provided, in order to encourage future authors to include detailed measurements on descriptions of larval sphecids.