Xanthopygus luctuosus ( Blanchard, 1842 )

Chatzimanolis, Stylianos, 2022, A revision of the genus Xanthopygus Kraatz (Staphylinidae: Xanthopygina), Zootaxa 5099 (2), pp. 151-178 : 160-161

Xanthopygus luctuosus ( Blanchard, 1842)

( Figs. 15–22 )

Staphylinus luctuosus Blanchard, 1842: 78 .

Creophilus luctuosus (Blanchard) ; Fauvel 1869: 487.

Lampropygus giganteus Bernhauer, 1906: 195 new synonymy.

Xanthopygus luctuosus (Blanchard) ; Newton 1996: 80.

Xanthopygus giganteus (Bernhauer) ; Herman 2001: 3607.

Type material. Lectotype for Staphylinus luctuosus , male, with labels: “6322 [opposite side “34”]” / “Muséum Paris, Coll. Générale” / “Type” / “ Lectotype Staphylinus luctuosus Bl. designated by Newton 1996 ” / “genus = Xanthopygus (Lampropygus) det. Newton 1996 ” / “ S. luctuosus Blanch. Valle Grande, M. d’Orbigny”. In the collection of MNHN. Newton (1996), after examining d’Orbigny field notes, hypothesized that the type locality of X. luctuosus is in Bolivia, Santa Cruz department, ‘one of the two mountain passes between Chilón and Mataral’ ( Newton 1996), with approximate coordinates -18.0°, -64.4°.

Holotype for Lampropygus giganteus , female, with labels: “Type” / “ giganteus Brh Type unic det. Bernhauer ” / “ Xanthopygus phylogeny voucher SC-001”. In the collection of NMW. Bernhauer (1906) indicated that he had only one specimen, therefore this specimen is the holotype. He also indicated that the specimen was from Brazil but without further details on the locality.

Additional Materials. BRAZIL: Rio de Janeiro: Rio [de Janeiro] [-22.91°, -43.20°] (1 ♀ ZMHB) ; unknown state: unknown locality, Dal Borgo leg. (1 ♀ NHMD) ; BOLIVIA: Cochabamba: Cochabamba [-17.383°, -66.166°], 2800 m, 6.xii.1946, Zischka leg., Scheepeltz coll. (1 ♂ NMW; this specimen was labeled as ms Type by Scheerpeltz) ; Unknown country: (1 ♀ ZMHB) .

Diagnosis. Xanthopygus luctuosus is (on average) the largest species in Xanthopygus but is rather similar to X. oliveirae . These two species ( X. luctuosus and X. oliveirae ) 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 luctuosus can be distinguished from X. oliveirae based on the following: antennomere 3 clearly longer than 2 (antennomere 3 subequal to 2 in X. oliveirae ); pronotum microsculpture polygon shaped (pronotum microsculpture with transverse lines in X. oliveirae ); and tergite 6 sparsely punctate (tergite 6 densely punctate in X. oliveirae ).

Description. Forebody length 12.4–17.3mm; HW/HL ratio = 1.31. Antennomere 3 clearly longer 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. 15–16 ); pronotum with one sparse row of punctures on each half beside median line; pronotum microsculpture polygon shaped. PW/PL ratio = 1.12. Mesoventrite with intercoxal process broad and rounded. Metacoxae with more than four spines (five or six) on posterior surface. EL/PL ratio = 1.38. Abdominal segments 4–6 without iridescent overtones; segment 6 without distinct bright band of orange coloration posteriorly; tergite 6 sparsely punctate; sternite 6 with two anterior transverse lines; segment 7 orange. In males, sternite 7 without porose structure; sternite 8 with shallow U-shaped emargination posteriorly. Aedeagus as in Figs. 19–21 ; in dorsal view paramere straight; apex emarginate; paramere slightly shorter and narrower than median lobe; in lateral view paramere almost straight; paramere with peg setae as in Fig. 21 . Median lobe in dorsal view converging to pointed apex; median lobe with subapical tooth; in lateral view median lobe becoming narrower near apex.

Distribution. Known from the departments of Cochabamba and Santa Cruz in Bolivia and the state of Rio de Janeiro in Brazil. The map is shown in Fig. 22 and online at https://www.simplemappr.net/map/16397.

Habitat. Unknown.

Remarks. The holotype of L. giganteus from NMW agrees with the type specimen of Staphylinus luctuosus examined in MNHM in every respect, thus L. giganteus is treated as a junior synonym of S. luctuosus . The non-type male specimen from Bolivia in NMW was labelled as manuscript name zischkai by Scheerpeltz, however, the specimen clearly belongs to X. luctuosus .

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 15–18. Xanthopygus luctuosus (Blanchard). 15. Habitus photograph. 16. Pronotum. 17. Sternites 6–8. 18. Antenna. Not to scale.

FIGURES 19–21. Aedeagus of X. luctuosus (Blanchard). 19. Dorsal view. 20. Lateral view. 21. Detail of paramere, ventral view.