kretschmanni ’ s global relatives: The Aphanogmus species with spiny sternite females (Hymenoptera, Ceraphronidae)

The Western Palaearctic Aphanogmus kretschmanni Moser, 2023 is unique among all described species of Ceraphronidae in having two distinct rows of spines on the seventh metasomal sternite of the female. In this study, we examined additional Aphanogmus that share this trait and found at least five additional putative species in an integrative taxonomy approach using morphology and publicly available CO 1 barcode data on BOLD.

Two new species are described herein: A. manta Schneider, Salden & Peters, sp. nov. and A. liceodosriosi Schneider, Salden & Peters, sp. nov. The diagnosis of A. kretschmanni is updated. The remaining putative species are listed but not formally described as reliable diagnoses require additional material.

We also describe males, including male genitalia, of species with spiny sternite females for the first time. Males lack the metasomal sternal spines which implies a sex-specific function of the spines, for example, in oviposition. In our morphological diagnoses, we use characters of the Waterston’s evaporatorium (WE) present on the sixth metasomal tergite in both males and females in addition to previously established morphological characters and further highlight the value of the WE in delimiting Ceraphronidae species and morphologically matching males and females.

The number of putative species and their distribution literally around the globe (Neotropics, Afrotropics, Palaearctic, Australasia, Orientalis) imply the presence of an unexpectedly large number of relatives of A. kretschmanni. Future investigations are necessary to capture the true diversity within the genus Aphanogmus and to unravel the biological and evolutionary background of the intriguing sternal spines.