Xanthopygus oliveirae Lynch, 1884

(Figs. 22, 37–39)

Xanthopygus oliveirae Lynch, 1884: 132 .

Type material. Neotype, here designated, female, with labels:” ♀ ” / “ Argentinien, Ang. Buenos Aires ” / “ Lampropygus oliveirae Lynch-Arribálzaga ” / “ex coll Scheerpeltz” / “ oliveirae Lynch-Arribálzaga ” / “ Xanthopygus phylogeny voucher SC-009” / “ Neotype Xanthopygus oliveirae Lynch-Arribálzaga, des. Chatzimanolis 2021”. In the collection of NMW.

Diagnosis. Xanthopygus oliveirae looks rather similar to X. luctuosus . These two species can be distinguished from all other species of Xanthopygus based on the following characters: antennomere 4 without tomentose pubescence; mandibles more or less straight except tip; eyes as long as 1/4 length of head; head appearing flat; and sternite 6 with two anterior transverse lines. Xanthopygus oliveirae can be distinguished from X. luctuosus based on the following: antennomere 3 subequal to 2 (antennomere 3 clearly longer than 2 in X. luctuosus); pronotum microsculpture with transverse lines (pronotum microsculpture polygon shaped in X. luctuosus); and tergite 6 densely punctate (tergite 6 sparsely punctate in X. luctuosus).

Description. Forebody length 10.7mm; HW/HL ratio = 1.2. Antennomere 3 subequal to 2; antennomere 4 subquadrate, without tomentose pubescence; antennomere 6 transverse. Mandibles more or less straight except apical tip. Eyes as long as 1/4 length of head; head appearing flat. Head and pronotum with small size punctures (see Figs. 37–38); pronotum with one sparse row of punctures on each half beside median line; pronotum microsculpture with transverse lines. PW/PL ratio = 1.13. Mesoventrite with intercoxal process broad and rounded. Metacoxae with more than four spines (five or six) on posterior surface. EL/PL ratio = 1.41. Abdominal segments 4–6 without iridescent overtones; segment 6 without distinct bright band of orange coloration posteriorly; tergite 6 densely punctate; sternite 6 with two anterior transverse lines; segment 7 orange. No males are known.

Distribution. Known only from the original (lost) type and the neotype locality in Argentina. The map is shown in Fig. 22 and online at https://www.simplemappr.net/map/16397.

Habitat. Unknown.

Remarks. The primary type is considered lost (Chani-Posse pers. comm.; the type was also not listed in any of the recent publications that discuss type materials from Argentina (Fernandez et al. 2007; Bachmann et al. 2017), and thus the designation of a neotype is necessary. It is worth mentioning that the original type locality (given in the description) of Arrecifes [-34.06, -60.10] in Argentina has been transformed to agricultural fields and probably looks rather different now than just before 1884 when this species was described. The type locality (Arrecifes) is shown on the map, which is in close proximity to the neotype locality (‘Buenos Aires’).