Diochus brooksi, Irmler, 2017

Irmler, Ulrich, 2017, A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 1-62 : 20-21

Diochus brooksi spec. nov.

urn:lsid:zoobank.org:act:E45E737C-D6F4-45D2-AD3A-712C3578AE37

Figs 20A–C , 39E , 43D

Type material: male, Holotype: Venezuela: Aragua, Rancho Grande , Biol. Stn. (10°21'N, 67°41'W), 1115 m elev., along stream, 8.3.1995, leg. R. Brooks, #062 ( KNHM).

Paratypes: Panama: Chiriqui Prov., Cerro Colorado , 1220 m elev., buttress with log, 3 females, litter u. small clump of bamboo-like grass, 1 male, 1 female, 5.1.1981, leg. W. Suter ( FMNH) ; same location, but 1290 m elev., 6 males, 3 females, litter small quebrada, 2 females, litter under Agave-like herb, 2 males, 1 female, litter at log, semidry, 1 female, grassy litter with fern, 6.1.1981, leg. W. Suter (13 FMNH, 2 UIC) ; same location, but 1220 m elev., under bamboo, 3 males, 7 females, 7.1.1981, leg. W. Suter ( FMNH) ; same location, but stage IV stump, passalid borrows, 7 females, 8.1.1981, leg. W. Suter ( FMNH) ; same location collector and date, but 1200 m elev., camp, grass litter on slope under bush, male, ( FMNH) ; same location collector and date, but 1450 m elev., flank Qda., buttress of large tree along slope, male, ( FMNH) ; same location, but 1290 m elev, litter in depression, 4 males, 5 females, tree buttress, 1 male, 6 females, litter at log, 1 male, 3 females, floor litter pocket nr. tree, 4 females, grassy ecotonal debris, male, 10.1.1981, leg. W. Suter (21 FMNH, 1 UIC) ; same location, but 1220 m elev., semi-dry slash, small clearing, 3 males, 2 females, 12.1.1981, leg. W. Suter ( FMNH) ; same location and elev., but wet basal pseudo-fork between small trees, male, litter of stage III stump, semidry, 3 males, 8 females, 13.1.1981, leg. W. Suter ( FMNH) ; same location, 1290 m elev., buttress tree hole, 1 male, 5 females, 14.1.1981, leg. W. Suter ( FMNH) ; same location, but 1225 m elev., litter at semi-exposed log abv. rd., 3 males, stump with Passalidae , female, 15.1.1981, leg. W. Suter ( FMNH) ; same location, but 1290 m elev., litter at buttress under lily, 2 males, 11 females, moss on strap fern rhizome, female, 17.1.1981, leg. W. Suter ( FMNH) ; same location, but 1235 m elv., stump with ant nest, 2 males, 1 female, litter u. cut twig pile in small hillside clearing, 2 males, stage V log, 1 male, 1 female, 23.1.1981 ( FMNH) ; same location, but 1210 m elev., litter u. rdside bushes, female, 25.1.1981, leg. W. Suter ( FMNH) ; same location, but drill site, 1210 m elev., litter at rdside under bush, 2 males, 24.1.1981, leg. W. Suter ( FMNH) ; same location, but 1210 m elev., litter u. rdside bushes, female, 25.1.1981, leg. W. Suter ( FMNH) ; same location, but 1290 m elev., buttress of small tree on slope, 2 females, litter at log, litter pocket, female, edge of wds, 5 males, 4 females, 1235 m elev., buttress treehole oak?, male, under seedling banana, female, 26.1.1981, leg. W. Suter (12 FMNH, 1 UIC) ; same location, but 1175 m elev., E side, gully litter, oak fringe, 2 males, 5 females, 27.1.1981, leg. W. Suter ( FMNH) ; Cocle Prov., El Valle, 2400 ft. elev., floor debris stream bed, male, 23.2.1959, leg. H.S. Dybas ( FMNH) ; Chiriqui Prov., Boquete , sifted, coffee tree litter, male, 2.10.1975, leg. D.S. Chandler ( FMNH) ; Canal Zone, Barro Colorado Il., Fairchild Trail , bark & under bark debris, same fallen tree as #171, female, 28.1.1959, leg. H.S. Dybas ( FMNH) ; Cerro Campana, Berlese , cloud forest leaf litter, 1 male, 1 female, 14., 23.2.1976, leg. A. Newton ( FMNH) ; Bocas del Toro Prov, Cerro Colorado, Qda. 3w, off hwy. 17, grassy litter, pathside clearing, 1490 m elev., 2 females, 11.1.1981, leg. W. Suter ( FMNH) ; Venezuela: same location and data as holotype, 1 male, 1 female, (1 KNHM, 1 UIC) ; same location, 1140 m elevation, flight intercept trap, male, 25.– 28.2.1995, leg. R. Brooks, #011 ( KNHM) ; same location, 1390–1420 m elevation, berlese leaf litter, female, 27.2.1995, leg. R. Brooks, #004 ( KNHM) ; same location and same collector, but 1115 m elevation, along stream, 1 male, 1 female, 8.3.1995, leg. R. Brooks #062, #063 ( UIC) ; Columbia: Meta Dept. 23 km NW Villavicencio, Quebrada Susumuko , 1000 m elev., forest litter, male, 5.3.1972, leg. S. & J. Peck ( FMNH) .

Diagnosis: Regarding the black colouration D. brooksi closely resembles D. ecuadoriensis within the D. maculicollis-group. It is distinguished from D. ecuadoriensis by the quadrate head and, in particular, by the slender curved paramere with three setae on the outer edge of the apex. From the similarly sized D. maculicollis , D. brooksi can be separated by the black head and pronotum.

Description: Length: 3.2 mm. Colouration: unicoloured black; legs and antennae yellow; medial antennomeres brownish; antennomeres four and five darker than six to ten.

Head 0.45 mm long, 0.41 mm wide; eyes slightly prominent; large; at least half as long as temples; EL: HL = 0.27; temples slightly divergent to posterior margin; PW: EW = 1.12; posterior margin widely convex; neck one third as wide as head width’s; setiferous punctation deep and moderately sparse; clypeus more densely punctate than vertex; vertex with impunctate midline; adjacent to midline row of four punctures; convergent posteriad; interstice between anterior pair one fourth wider than between posterior pair close to neck; laterad to medial row of punctures another irregular row of punctures; postocular area densely punctate; microsculpture weak; transversely reticulate; surface slightly shiny.

Antennae as long as head and one third of pronotum combined; first antennomere thick; antennomeres two and three conical; slightly narrower and shorter than first; one fourth longer than apical width; following antennomeres wider than long; fourth nearly quadrate; ninth twice as wide as long; all antennomeres pubescent; basal antennomeres with few setae.

Pronotum 0.61 mm long, 0.48 mm wide; sides nearly parallel; anterior angles widely rounded; posterior angles rounded but slightly more angulate than anterior angles; lateral margin fine; in dorsal aspect, visible in posterior half; setiferous punctation as deep as on head, but sparser; wide midline impunctate; adjacent to midline with row of three punctures; interstice between anterior pair of punctures more than twice as wide than between posterior pairs of punctures; laterad to medial row of punctures three to four punctures; along lateral margin several setiferous punctures; without microsculpture; surface polished.

Elytra 0.63 mm long, 0.61 mm wide; shoulders obtusely angled; sides divergent to posterior margin; posterior margin concave; setiferous punctation in irregular rows of five to six punctures; between rows of setiferous punctures with finer and sparse punctation.

Abdomen densely pubescent.

Aedeagus slender; seminal vesical of endophallus elongate; nearly two third as long as central lobe; basal inner duct looped; ending in complex sclerotised structure; slender paramere not projecting central lobe; not widened to apex; apical half curved and with three long setae at outer side; three sensillae at outer side of shaft.

Spermatheca 0.21 mm long, 0.21 mm wide; bursa copulatrix in marginal or lateral position to coiled duct; coiled duct nearly circular, but irregularly coiled.

Etymology: The species is named to honour the collector of the species, Richard Brook, who collected extensively Staphylinidae in the Neotropical region.

Figures

Figs 43: Fore-bodies of Diochus schuelkei (A), D. tricolor (B), D. vicinus (C), D. brooksi (D), D. ecuadoriensis E), D. maculicollis (F), D. mexicanus (G), D. peruvianus (H); scale bar: 0.5 mm.

Figs 18–21: Diochus inornatus-group: D. plaumanni (18), D. newtoni (19) and Diochus maculicollis-group: D. brooksi (20), D. ecuadoriensis (21); aedeagus (A), paramere (B) and antenna (C); scale bar: A, B: 0.1 mm, C: 0.2 mm.

Fig. 39: Spermathecae of Diochus inornatus-group: D. schuelkei (A), D. plaumanni (B), D. tricolor (C), D. vicinus (D); Diochus maculicollis-group: D. brooksi (E), D. ecuadoriensis (F), D. maculicollis (G), D. pumilio (H), D. peruvianus (I), D. mexicanus (J), D. panamaensis (K); Diochus schaumii-group: D. angustiformis (L); scale bar: 0.1 mm.