Head anatomy of adult Nevrorthus apatelios and basal splitting events in Neuroptera (Neuroptera: Nevrorthidae)

Abstract

External and internal features of the head of adult Nevrorthus apatelios are described in detail. The results are compared with data from literature. The mouthpart muscle M. stipitalis transversalis and a hypopharyngeal transverse ligament are newly described for Neuroptera and herewith reported for the first time in Endopterygota. A submental gland with multiporous opening is described for Nevrorthidae and Osmylidae and is apparently unique among insects. The parsimony analysis indicates that Sisyridae is the sister group to all remaining Neuroptera. This placement is supported by the development of 1) a transverse division of the galea in two parts in all Neuroptera excluding Sisyridae, 2) the above mentioned submental gland in Nevrorthidae and Osmylidae, and 3) a poison system in all neuropteran larvae except Sisyridae. Implications for the phylogenetic relationships from the interpretation of larval character evolution, specifically the poison system, cryptonephry and formation of the head capsule are discussed. © Senckenberg Gesellschaft für Naturforschung, 2014.