Oxyrrhexis Förster, 1869

Khalaim, Andrey I., Ruíz-Cancino, Enrique & Coronado-Blanco, Juana María, 2024, Darwin wasps of the subfamily Pimplinae (Hymenoptera: Ichneumonidae) of Mexico: Polysphincta genus-group, Zootaxa 5458 (2), pp. 151-196 : 170-171

Genus Oxyrrhexis Förster, 1869

Oxyrrhexis Förster 1869: 166 . Type species: Cryptus carbonator Gravenhorst, 1807 , by monotypy ( Schmiedeknecht 1888: 432; see also Perkins 1962: 441).

References. Viereck 1914: 108 [syn. of Acrodactyla ]. Townes & Townes 1960: 242 [description; 1 species in Nearctic region]. Townes 1969: 106 [diagnosis]. Carlson 1979: 336 [catalogue; 1 species in North America]. Gauld & Dubois 2006: 552 [description; Holarctic genus with 2 species]. Liu et al. 2009 [review of 3 species from China (2 described as new); key]. Fritzén & Fjellberg 2014 [review; 1 new species from Norway; host, biology].

Oxyrrhexis is a small genus with four species: two species in Eastern Palaearctic region and Oriental China, one recently described species from Norway ( Fritzén & Fjellberg 2014), and one widely distributed Holarctic species, O. carbonator . The latter species, as well as the genus Oxyrrhexis , is recorded here from Mexico for the first time.

Oxyrrhexis is very similar to Polysphincta , but differs from this genus by the shorter ovipositor and more densely and coarsely punctate metasomal tergites ( Townes & Townes 1960; Townes 1969). Three Costa Rican species of Polysphincta also possess a rather short ovipositor and their generic placement may need to be reassigned ( Gauld 1991: 308).

Species of Oxyrrhexis are koinobiont ectoparasitoids of adult spiders. Fritzén & Fjellberg (2014) supposed that Oxyrrhexis is a genus specialized on spiders of Theridiidae and might be restricted to only two theridiid genera, Steatoda Sundevall and Enoplognatha Pavesi , or to subfamilies Asageninae, Enoplognathinae and less likely also Theridiinae.