Brachygluta (Brachygluta) tamaulipec Sabella

Chandler, Donald S., Sabella, Giorgio & Bückle, Christoph, 2015, A revision of the Nearctic species of Brachygluta Thomson, 1859 (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 3928 (1), pp. 1-91 : 45-48

14. Brachygluta (Brachygluta) tamaulipec Sabella , sp. n.

( Figs 18–19 , 39 C)

Material examined, 3 specimens. HOLOTYPE male: MEXICO: Tamaulipas: // MEX: Tamaulipas: La Pesca, 20 Sept. 1981, W.H. Cross/ blacklight trap/ [red label] HOLOTYPE Brachygluta tamaulipec Sabella // ( FMNH). Non-type specimens, 2 females: Texas: Cameron Co.: 1.5 mi E jct. FM 1419 on Hwy. 4, E of Brownsville, X-19- 2002, B. Raber & E. Riley, UV light ( DSCC, 1; TAMU, 1).

Description. BODY: Length 2.32–2.40 mm; brown, with elytra orange-brown; setae over body short, strongly curved and suberect to decumbent. Head: surface smooth, shining, punctures indistinct. Setose area of median vertexal fovea about smaller than those of lateral foveae; antennomeres (both sexes) III–VII longer than wide, VIII transverse, IX–X as long as wide, VIII two-thirds width of IX ( Fig. 19 A). Pronotum: surface smooth, shining, small punctures distinct; setose area of median antebasal fovea smaller, about two-thirds width of those in lateral antebasal foveae. Elytra: surface lightly punctate, opaque due to light microreticulation, discal stria extending to about four-fifths of elytral length. Abdomen: surface smooth, shining, punctures indistinct. Basal striae of tergite 1 short, one-fifth to one-sixth as long as paratergite, striae separated by about one-half tergite width; basal setose brush between striae distinct.

MALE: Antennae lacking modifications. Protrochanter with ventral acute spine ( Fig. 19 C). Metaventrite with broad impression at middle, setae sparse laterally, denser in impression. Tergite 1 with apex protruding as rounded subtruncate lobe, apex with two close, ventrally directed tufts of setae forming flattened lamina, lateral margins of lobe with dense short setae, appearing densely punctate; tergite 2 base raised at middle as transverse carina, difficult to see, two shallow oval impressions centered on tergite disc; tergite 3 narrowly impressed at base ( Figs 18 A-B); in lateral view tergite 1 rising posteriorly to deflexed apex, tergite 2 nearly level, apex of 1 well-elevated above 2 ( Fig. 18 C). Abdominal ventrites broadly convex. Metatibiae narrow basally, slightly widening through length to apex, with dense comb of setae on mesal margin in apical fifth where slightly curved medially ( Fig. 19 B). Aedeagus 0.44 mm long; dorsal plate indistinct; parameres elongate and sinuous, lacking distinct preapical constriction in dorsal view, with slight mesal angulation in lateral view ( Fig. 19 E); with elongate thin mesal hyaline seta, similar in form to three short lateral setae; internal sac with one large straight spine and with thick, strongly curved spine complex ( Fig. 19 D).

FEMALE: Two probable females have: metaventrite with long setae, setae denser in triangular area from between metacoxae to metasternal base; basal carinae of tergite 1 slightly longer, about one-fifth as long as tergite, basal separation of carinae narrower, about two-fifths width of tergite. Abdominal ventrites broadly rounded. Metatibiae similar to those of male.

Collecting data. The holotype was collected in September, with the collecting technique unknown. The two probable females were taken by an ultraviolet light in October.

Distribution ( Fig. 39 C). The holotype and associated females were taken at sites at or near the Caribbean coast in Texas and Tamaulipas. The two sites are 240 km apart.

Comments. The two females match up well with the holotype in terms of coloration, size, antennal form, very short basal carinae of tergite 1, and setation. The male and females differ only in the relative width between the basal carinae, and have slight differences in lengths of the basal carinae. This can vary between sexes in other species, and based on the geographic closeness and coastal habitat, these females are very likely conspecific.

The prominent median non-emarginate lobe of tergite 1 of the male, and the relatively simple tergite 2 place this species near B. dentata . The apex of tergite 1 is subtruncate in B. tamaulipec and the metaventrite is broadly impressed, while the lobe apex is bluntly angular and the metaventrite nearly convex (slightly longitudinally impressed at the middle) in B. dentata .

The holotype is a specimen from the Mississippi Entomological Museum, Mississippi State University, and is gifted to the FMNH courtesy of Terry Schiefer.

Etymology. The name is taken from the group of indigenous people most closely identified with the locality of the holotype specimen.

Figures

FIGURE 18. Brachygluta tamaulipec Sabella (Mexico, Tamaulipas, holotype). A: Abdomen, dorsal view. B: Abdomen, caudal view. C: Abdomen, lateral view.

FIGURE 19. Brachygluta tamaulipec Sabella (Mexico, Tamaulipas, holotype). A: Right antenna. B: Left metatibia, posterior view. C: Left protrochanter, posterior view. D: Aedeagus. E: Aedeagus, left paramere.

FIGURE 39. Distribution map of Brachygluta dentata species-group. A: Brachygluta dentata (Say) (excluding Texas and Illinois, see text). B: Brachygluta lareaui Chandler. C: Brachygluta tamaulipec Sabella. (Red dot: material examined, green dot: only state on label).