The genital morphology of Zorotypus hubbardi Caudell, 1918 (Insecta: Zoraptera: Zorotypidae)

Abstract

The internal and external genitalia of both sexes of Zorotypus hubbardi Caudell 1918 were examined. A detailed description is provided, especially for the male genitalia. The results were compared with the conditions in potentially related neopteran groups. Most features of the internal genitalia of both sexes are plesiomorphic. Putative autapomorphies are: fusion of the distal parts of the vasa deferentia, division of the ductus ejaculatorius (de) into two sections by a distinct circular furrow, dorso-median processes on tergites VIII–X, an asymmetric aedoeagus with a cryptic slit-like phallotrema, reduction of the right outer paramere, the specific asymmetric shape of the endophallus with three conspicuous pouches, the endophallic sclerites scl1–scl6 and their specific arrangement, the specific arrangement of the endophallic muscularis and the unpaired genital muscles m2, m4, m5, m6 and m7. These features cannot be regarded as autapomorphies of the whole order Zoraptera with reliability, as the morphology of the external male genitalia seems to be highly variable within the genus Zorotypus and the intra-generic relationships are poorly resolved. Potential synapomorphies were found with several neopteran groups under comparison: with Embiidina a strengthened muscularis surrounding the de, reduction of the ovipositor and a shortened tergite IX, with Psocoptera the occurance of dense sperm bundles and with Hemiptera a strengthened muscularis of the de. No synapomorphies were found with Dictyoptera. Homologies of the muscles m1 and m3 found in Z. hubbardi with some genital muscles in Dictyoptera and Psocoptera are highly ambiguous.