Genus Pygostolus Haliday

Pygostolus Haliday, 1833: 263

Type species: Ichneumon sticticus Fabricius, 1798

Comments. Previously the genus Pygostolus included seven described species worldwide of which P. sonorensis Cameron and P. sticticus Fabricius have been reported from the neotropical region, Mexico and Argentina respectively (Yu et al., 2016), but the placement of P. sonorensis in this genus is dubious. Cameron (1887) in the original description attests: “I am somewhat doubtful if the species here described belongs to this genus.” and also mention that this species has “…; ovipositor not projecting.”, “…; the second cubital cellule at the apex twice the width of the base…”, moreover there is no mention of a setose mesosoma, indicating that this specimen does not belong to the genus Pygostolus . We were unable to locate the holotype to check those characteristics and the correct placement of this species. Nevertheless, even if P. sonorensis did indeed belong to the genus Pygostolus the presence of the prior mentioned characters and also a short metasoma ("Abdomen scarcely so long as the thorax") and short T1 ("…shorter than the second segment") should be enough to clearly differentiate it from both species described below.