Brachygluta (Nisa) cavicornis Brendel 1865
Creators: name: Chandler, Donald S.
name: Sabella, Giorgio
name: Bückle, Christoph
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Brachygluta
Brachygluta cavicornis

description: 1. Brachygluta (Nisa) cavicornis (Brendel, 1865)
(Figs 1–2, 35A)
Bryaxis cavicornis Brendel, 1865a: 30. Type locality: Virginia. Type depository: MCZC. Lectotype male (Chandler, 1994): // Va./ B. cavicornis Brendel / MCZ Syntype 33390/ Lectotype B. cavicornis Brend. design. D.S. Chandler 1994 / Aug.-Dec. 2004 MCZ Image Database//. Brendel 1866a: 34. LeConte 1880: 182. Blatchley 1910: 318. Moxey 1962: 97.
Bryaxis (Nisa) cavicornis: Brendel & Wickham 1890: 267 (key), 275 (redescription), plate VIII, fig. 49.
Brachygluta cavicornis: Raffray 1904: 226; 1908: 231; 1911: 95. Leng 1920: 130. Bowman 1934: 88 (Group III, key).
Chandler 1994: 49 (lectotype designation); 1997: 55. Downie & Arnett 1996: 582. Poole & Gentili 1996: 380. Nisa cavicornis: Casey 1886: 183.
Material examined, 121 specimens. USA: District of Columbia: D.C. (ANSP, 1; CMNH, 13); D.C., Brend., Horn Coll. H1927/ 8303.1 PARATYPE (MCZC, 1). Piney Bridge, V-12-1905, D.H. Clemons (FMNH, 1). Wash.(ington), VI-18, Hubbard & Schwarz (USNM, 1). Maryland: Baltimore Co.: Baltimore, VI-10-1909, F.E. Blaisdell (MCZC, H.C. Fall Collection, 1). Hawkins Point, VII-3-1966, E.J. Ford, Jr. (light trap DSCC, 2). Cecil Co.: Cecilton, VI-2-1955, R.S. Howard (FMNH, 1). Charles Co.: Indian Head, V-12-1944, G.B. Vogt, at light (USNM, 1). Kent Co.: Eastern Neck Island, III-27-1956, R.S. Howard (FMNH, 4). Montgomery Co.: near Plummers Island, V-22-1915, R.C. Shannon (LSAM, 1). Only state on label: “Md.” (CMNH, 1). Massachusetts: Plymouth Co.: Humarock, V-8-1933, C.E. White (MCZC, 1). New Hampshire: Rockingham Co.: Seabrook backdunes, 1 m, VIII-3-1989, D.S. Chandler, UV light (DSCC, 1). New York: Queens Co.: Rock(away) Beach, L.(ong) I.(sland), VI-11-1922 (USNM, 1). Richmond Co.: Staten Island, III-17-1921, A. Nicolay (MCZC, H.C. Fall Collection, 3; USNM, 13; CNCI, 1; AMNH, 2; ANSP, 8); V-8-1921 (USNM, 21); V-1-1920 (ANSP, 1); III-17- 1921 (MCZC, 1); IV-1906, salt meadow (CMNH, 1); V-12, salt meadow (MCZC, 1; DSCC, 1); VII (MCZC, 6); V- 18 (MCZC, 2); IV-26, salt marsh (MCZC, 1); III-17 (FMNH, 1), IV-26 (MCZC, 1), XI-10 (FMNH, 1), host Myrmica sabuleti MT; IV-1906, salt meadow (MCZC, 6); no date (CUIC, 1; DSCC, 1; FMNH, 14). North Carolina: Mecklenburg Co.: Davidson, X-22-1965, T. Daggy (NCSU, 1). Virginia: Spotsylvania Co.: Fredricksburg, V-9-1891, W.D. Richardson (USNM, 1). Only state on label: “Va.” (MCZC, Lectotype; CMNH, Paralectotype).
Description. BODY: Length 2.48–2.64 mm; orange-brown to elytra orange-brown and rest of body brown; setae on pronotum short, curved and suberect, decumbent over rest of body. Head: surface lightly reticulate to smooth, shiny, punctures minute. Median vertexal fovea setose usually punctiform but sometimes shallow, one-half width to nearly as large as lateral vertexal foveae. Antennae strongly modified in male. Pronotum: with surface smooth, shiny to lightly microreticulate, with distinct, small punctures separated by about twice their width. Median antebasal fovea one-half to two-thirds width of lateral antebasal foveae. Elytra: surface microreticulate, punctures indistinct; discal stria extending to about four-fifths of elytral length. Abdomen: surface smooth, punctures small but distinct; basal striae of tergite 1 extending nearly to one-third paratergite length, at base striae separated by about two-fifths tergite width, with short and sparse setal brush between striae.
MALE: Antennomere III elongate, IV–V transversely rectangular, VI–VIII transversely triangular in lateral view, IX transverse, bluntly pointed on lateral margin, articulation of IX and X offset medially on IX, X elongate, asymmetrically flattened on mesal margin, gently convex on lateral margin, with apex of elongate, thin hyaline tubercle arising near base and with apex abruptly (Figs 2 A–B); XI with asymmetric ventrolateral lobe in basal half, apical half broad and twisted (Fig. 2 C). Protrochanter with small acute ventral spine at base (Fig. 1C); mesotrochanter with prominent narrow spine with blunt apex (Fig. 1D); metatrochanter with acute ventral spine at apex (Fig. 1E). Metaventrite with broad impression at middle, setae in impression denser than laterally, elongate and appressed. 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. 1B). Abdominal tergites unmodified (Fig. 1A); ventrites 2–4 flattened at middle, 5 shallowly impressed at middle. Aedeagus 0.54 mm long; with dorsal plate transversely pentagonal, apex bluntly pointed; parameres short and broad, with three thick setae on outer margin in area of preapical constriction, flat preapical hyaline setae very large, nearly as wide as long; internal sac with three large curved spines (Fig. 2 D).
FEMALE: Similar to male except: antennomeres IV–V slightly longer than wide, VI–VII about as long as wide, VIII slightly transverse, IX slightly longer than wide, X longer than wide, swollen ventrally. Metatibiae similar to those of male. Metasternum with disc convex, lacking denser setae posteriorly. Abdominal ventrites convex.
Collecting data. With ant, Myrmica sabuleti, in salt marsh; at UV light (Chandler, 1997). Adults have been taken from March to July, with a single record from October in North Carolina. This species has been collected in salt marshes and is attracted to ultraviolet lights.
Distribution (Fig. 35 A). Blatchley (1910) recorded this species from Indiana based on two specimens from Putnam and Posey Counties. Examination of these two specimens revealed a female of Batrisodes lineaticollis (Aubé) (Posey Co., IX-29-1909), and an unplaced female of Rybaxis (Putnam Co., X-10-1909). Brachygluta cavicornis is a species of the eastern seaboard salt marshes, and is known from New Hampshire to North Carolina.
Comments. Readily separated from the other members of the cavicornis species-group by the elongate discal striae of tergite 1, which are indistinct in the other species, and the large setose median vertexal fovea of the head, which is smaller to lacking in the other species. The range and habitat of B. cavicornis overlaps to a large extent with that of B. luniger, but does not extend to the northern and southern extremes of that species.
description: Published as part of Chandler, Donald S., Sabella, Giorgio & Bückle, Christoph, 2015, A revision of the Nearctic species of Brachygluta Thomson, 1859 (Coleoptera: Staphylinidae: Pselaphinae), pp. 1-91 in Zootaxa 3928 (1) on pages 10-13, DOI: 10.11646/zootaxa.3928.1.1, http://zenodo.org/record/288057