Xanthopygus major ( Bernhauer, 1917 )

Chatzimanolis, Stylianos, 2022, A revision of the genus Xanthopygus Kraatz (Staphylinidae: Xanthopygina), Zootaxa 5099 (2), pp. 151-178 : 163-164

Xanthopygus major ( Bernhauer, 1917)

( Figs. 22–29 )

Lampropygus major Bernhauer, 1917: 116 .

Xanthopygus major (Bernhauer) ; Herman 2001: 3608.

Type material. Lectotype, here designated, male, with labels: “Villavicencio [4.13°, -73.60°], i. 1911, 440m” / “ ♂ ” / “Columbia occ. Fassl” / “ Lampropygus major Bernh. Typus” / “Chicago NHMus M. Bernhauer Collection ” / “FMNHINS3975383 Field Museum Pinned” / “ Xanthopygus phylogeny voucher SC-005” / “ Lectotype Lampropygus major Bernhauer des. Chatzimanolis 2021”. In the collection of FMNH . Paralectotype, here designated, female, with labels “Villavicencio [4.13°, -73.60°], i. 1911, 440m” / “ ♀ ” / “Columbia occ. Fassl” / “ Lampropygus major Bernh. Cotypus ” / “Chicago NHMus M. Bernhauer Collection ” / “FMNHINS3975384 Field Museum Pinned” / “ Xanthopygus phylogeny voucher SC-006” / “ Paralectotype Lampropygus major Bernhauer des. Chatzimanolis 2021”. In FMNH .

Diagnosis. Xanthopygus major looks rather similar to X. max and X. pexus and it could be hard to distinguish these three species. In all of these species, abdominal segment 7 is black with posterior 1/2 or posterior 1/3 orange; in X. pexus it is typically 1/2 orange but the degree of coloration can vary. Xanthopygus major and X. max can be distinguished from X. pexus based on the following characteristics in combination: head and pronotum with small to medium size (see Figs. 23–24 ) punctures (medium to large size punctures in X. pexus ); pronotum with one sparse row of punctures on each half beside median line (pronotum with 1–2 dense rows of punctures on each half beside median line in X. pexus ); abdominal segments 4–6 not iridescent under strong light (abdominal segments 4–6 with iridescent overtones under strong light in X. pexus ). Xanthopygus major can be confidently distinguished from X. max only by examining the paramere; in X. major the paramere is apically rounded, whereas in X. max it is apically emarginate.

Description. Forebody length 11.5–12.6mm; HW/HL ratio = 1.27. Antennomere 3 longer to 2; antennomere 4 subquadrate, with tomentose pubescence; antennomere 6 transverse. Mandibles curved from apical half. Eyes as long as 1/3 length of head; head appearing convex. Head and pronotum with small to medium size punctures (see Figs. 23–24 ); pronotum with one sparse row of punctures on each half beside median line; pronotum microsculpture with transverse lines. PW/PL ratio = 1.10. Mesoventrite with intercoxal process broad and rounded. Metacoxae with more than four spines (five or six) on posterior surface. EL/PL ratio = 1.28. Abdominal segments 4–6 without iridescent overtones; segment 6 without distinct bright band of orange coloration posteriorly; tergite 6 densely punctate; sternite 6 with single anterior transverse line; segment 7 black with posterior 1/4 orange. In males, sternite 7 without porose structure; sternite 8 with shallow U-shaped emargination posteriorly. Aedeagus as in Figs. 27–29 ; in dorsal view paramere converging to rounded apex; paramere shorter and narrower than median lobe; in lateral view paramere almost straight; paramere with peg setae as in Fig. 29 . Median lobe in dorsal view converging to rounded apex; median lobe with subapical tooth; in lateral view median lobe becoming narrower near apex.

Distribution. Only known from the type locality in the department of Meta in Colombia. The map is shown in Fig. 22 and online at https://www.simplemappr.net/map/16397.

Habitat. Unknown.

Figures

FIGURE 22. Distribution map of X. luctuosus (Blanchard) (white squares), X. major (Bernhauer) (star), X. max Blackwelder (black squares) and X. oliveirae Lynch (circle).

FIGURES 23–26. Xanthopygus major (Bernhauer). 23. Habitus photograph. 24. Pronotum. 25. Sternites 6–8. 26. Antenna. Not to scale.

FIGURES 27–29. Aedeagus of X. major (Bernhauer). 27. Dorsal view. 28. Lateral view. 29. Detail of paramere, ventral view.