The female genitalic region in Eudermaptera (Insecta: Dermaptera)

Dermaptera includes the ‘lower’ subgroups Pygidicranidae, Diplatyidae, and Karschiellidae, the more derived ‘higher’ Dermaptera Apachyidae, Labiduridae, Anisolabididae, Chelisochidae, Forficulidae, and Spongiphoridae (the three latter forming the Eudermaptera), and the epizoic Hemimeridae and Arixeniidae. The female genitalic region of Dermaptera shows a wide morphological range. As documented previously, it is highly complex and morphologically diverse in the ‘lower’ families. In the ‘higher’ and the epizoic Dermaptera it is strongly modified and reduced, but morphological data are sparse, and entirely lacking for Eudermaptera. Herein the female genitalic region is described for six species of Forficulidae (Forficula auricularia, Anechura bipunctata), Chelisochidae (Chelisoches morio), and Spongiphoridae (Sphingolabis hawaiiensis, Spongovostox semiflavus, Marava arachidis). S. hawaiiensis is ovoviviparous or viviparous, M. arachidis is ovoviviparous, the remaining species are oviparous (no data on S. semiflavus). The female genitalic region is overall quite similar in these eudermapterans, but there are differences in many details. Morphology is compared among these species and a list of 27 characters is compiled; this forms the first step towards using female genitalic characters in forthcoming phylogenetic studies and taxonomic work on Eudermaptera. The female genitalia show different specialisations in the two sampled (ovo)viviparous species, including the presence (M. arachidis) vs. absence (S. hawaiiensis) of a spermatheca. This indicates that (ovo)vivipary evolved independently in these taxa. Morphology in the eudermapterans is briefly compared with that in ‘lower’ dermapterans, and the morphological interpretation of the eudermapteran gonopore and genitalic sclerites is discussed.