Asthenolabus Heinrich, 1951 Stenolabus Heinrich, 1935: 197. Type species: Platylabus lastiscapus Thomson, 1894, by original designation. Preoccupied by Stenolabus Schulthess-Rechberg, 1910 (Hymenoptera: Vespidae). Asthenolabus Heinrich, 1951: 240. New replacement name for Stenolabus, 1935. Comparative diagnosis The very elongate and narrow sickle-shaped propodeal spiracles (Figure 9b) set Asthenolabus apart from Apaeleticus, Carlsonia, Cyclolabus and Lincyus (all with small and round propodeal spiracles). However, this feature places Asthenolabus close to Platylabus and Tropicolabus from which it can be distinguished by the very superficial, almost obsolete, gastrocoeli and thyridia (Figure 9d), and to Probolus from which it can be distinguished by the presence of propodeal carinae and the absence of a hump in the anterior part of the postepetiole (Heinrich 1961, 1962b; Tereshkin 2009). Range and diversity The genus is known only from the Nearctic, Palearctic and Indomalayan regions, with three species in North America, of which only one, Asthenolabus canadensis (Cresson, 1877), occurs in the south-eastern United States (Heinrich 1962b; Yu et al. 2016).

Published as part of Dal Pos, Davide, Heilman, Victoria & Welter-Schultes, Francisco, 2022, Platylabini (Hymenoptera: Ichneumonidae: Ichneumoninae) of the south-eastern United States: new distributional data, taxonomic notes, illustrated keys, and an annotated catalogue of the genera and species, pp. 1869-1938 in Journal of Natural History 56 on pages 1882-1884, DOI: 10.1080/00222933.2022.2134061, http://zenodo.org/record/7397619