Heterolinus basiniger, Marquez, 2001

Márquez, Juan, 2001, Systematic Review Of Heterolinus Sharp (Coleoptera: Staphylinidae: Xantholinini), The Coleopterists Bulletin 55 (3), pp. 317-329 : 321-323

Heterolinus basiniger new species

Fig. 2

Description. Length 17.75 mm. Body compressed. Apex of last antennomere, labial and maxillary palpi, apical tarsomere of anterior tarsi, and middle and hind tarsi rufotestaceous; visible abdominal segments 5–7 and genital yellow, except black base of the fifth; rest of the body black. Head heart­shaped; posterior corners acute, with oblique impressed line near them; dorsal surface with deep punctures, heterogeneously distributed, denser at sides and middle; area between frontal channel without punctures, but with microsculpture as on the base of mandibles; antennal channels as long as middle part of cephalic length, deeper than frontal and ocular channels, with six setiferous punctures, middle puncture with the main big setae; frontal channel reaching posterior border of the eye, curved and without punctures; ocular channel inconspicuously developed, as wide as antennal channel, with rugose microsculpture; with two setiferous punctures in each middle part of posterior border, in addition to three setiferous punctures near left corner and three near to right corner. Short eyes (more than four times the length of lateral part of the head). Labrum conspicuous, narrow and long, with fine longitudinal middle suture, two big setae on each middle part, and another five or six shorter. Left mandible with two acute teeth, basal longest; right mandible with two blunt teeth, less developed than left one. Labial palpi long, last palpomere about 1.5 times as long as previous segment. Maxillary palpi long, last palpomere as long as penultimate. Antennae geniculate very long, crossing middle part of pronotum when directed backwards; first antennomere longer than next two combined and the widest, second as long as 2/3 the length of 3rd, 4th less transverse than the following seven, 5th to 10th transverse, 9th and 10th less wide than the previous five, apical acuminate, as wide as penultimate; antennomeres 1 to 6 with long setae combined with few short setae, 7 to 11 with abundant short setae and few big setae. Ventral surface of head with flat or slightly depressed lateral areas with rugose and reflecting microsculpture different from that of other zones, limited by a lateral border that is slightly carinate and by the elevated central area which is divided by united gular sutures; punctation denser that on dorsal surface, but denser in the posterior and flat areas, this latter with a setiferous puncture on the middle part and one on the anterior part; middle anterior area nearly smooth. Neck narrow (3.6 to 4.5 times narrower than posterior border of head). Pronotum narrower than head; wider anteriorly, lateral border conspicuously curved slightly anterior to the middle of its length; all corners rounded; with more setae at lateral border; microsculpture inconspicuous; two pairs of punctures flank the midline anteriorly; with a few lateral punctures. Upper and lower line of pronotal hypomera united at procoxae level. Scutellum with microsculpture of wavy lines, and with some apical setiferous punctures. Elytral punctures conspicuous but moderately dense; each puncture with a short seta; with five setiferous punctures lined longitudinally; scarce big setae on external and internal borders, only abundant on external posterior angles; posterior border conspicuously rugose. Prosternum with microsculpture of wavy lines. Mesosternum short and metasternum long, as long as 2.5 times the length of mesosternum. First legs more robust than middle and last legs, last legs shorter and narrower. Anterior tibiae with apical and subapical ctenidium and two apical spines; tarsomeres 1 to 4 slightly dilated and with many apical fine setae; apical tarsomere longest and narrowest, 4th short. Middle tibiae with five ctenidia on inner part; first tarsomere wider and longer than the next three combined, 4th shorter, and 5th longest. Posterior legs similar to middle legs. Abdominal segments with abundant setae, long and dark setae distributed on lateral borders. Genital sternum and tergum as in figures 5 and 9, respectively. Aedeagus as in figure 17, parameres reduced, with conspicuous internal sac.

Variation. Length from 15.60 to 17.75 mm. With two or three setiferous punctures near to posterior angle of the head, paired or not. Punctures of the central part of the head are in most specimens posterior to the last big setae enclosed in the antennal channel; two specimens examined had a few punctures more anterior. Medial punctures at anterior part of pronotum, one, two or three, paired or not, punctures heterogeneously distributed. The black base of the fifth abdominal segment visible is normally short and little visible when the abdominal segments are not stretched; only in one specimen of Colombia was it as long as ½ the length of the segment .

Remarks. This species can be distinguished from H. puncticeps , which is very similar, by the two or three setiferous punctures near posterior angles of the head; the cephalic punctures not anterior to the last punctation level of the antennal channel; punctures on anterior part of pronotum; black base of fifth visible abdominal segment; different shape of internal sac of aedeagus; and with little constancy (variable character in the specimens of the three Heterolinus species analyzed) by the big head. It is distinguished from H. xanthogaster by the same characters as above (except that the anterior punctures of the pronotum are similar) and because H. xanthogaster has the abdomen fully red and the antennae and legs rufotestaceous.

Geographical Distribution. Known from Costa Rica (type locality), Colombia, and Ecuador ( Fig. 19 ) .

Type Material. Holotype male: Heterolinus puncticeps D. S. Costa Rica. Van Patten. (in the plate with the specimen)/Sp. figured/ Costa Rica. Van Patten/B. C. A. Col. I. 2 Heterolinus puncticeps, Guerin. ( BMNH). Paratypes: R. Sn Lorenzo, 1,050 m. Tierras Morenas, R. F. Cord. Guanacaste, Prov. Guan. Costa Rica. C. Alvarado, Nov 1991, L­N­287800, 427600 (1F, INBIO). Est. La Casona, 1,520 m, Res. Biol. Monteverde, Prov. Puntarenas, Costa Rica, May. 1992. N. Obando. L­N 253250, 449700/ Costa Rica INBIO CR1000 728708 (1F, INBIO). San Luis, 1,040 m, R. B. Monteverde, Prov. Punt., Costa Rica. Abr 1993. Z. Fuentes. L­N­250850, 449250 (1F, INBIO). R. San Lorencito, 900 m, R. F. San Ramón, 5 km N de Colonia Palmarena, Prov. Alaju., Costa Rica. 13–18 Jun 1993. I Curso de Scarabaeide. L­N­244500, 470700 (1M, 1F, INBIO). Alajuela, Costa Rica, San Ramón, Rio S. Lorencito. 800 m. 4 Mayo 1987 col: A. Solís Blanco (1F, INBIO). Costa Rica: Alajuela, Peñas Blancas, 900–1,500 m, 20 May 1989 J. Ashe, R. Brooks, R. Leschen/Snow Entomol. Mus. Costa Rica Exped. #308/ Heterolinus puncticeps Guér det. J. S. Ashe 19 (1M, SEMC). Costa Rica: Orosi 1,300 m Fassl/ puncticeps Guér. det. Bernhauer/Chicago N. H. Mus. M. Bernhauer Collection (1F, FMNH). Tapanti, III.41 (Valerio) Costa Rica / Heterolinus puncticeps (Guérin) /Field Mus. Nat. Hist. 1966 A. Bierig Colln. Acc. Z­13812 (1F, FMNH). Bogota/ Xantholinus N. Sh. (1M, BMNH). Rio Vitaco. 2,200 m /Columbia occ. Cali, Fassl/ puncticeps Guér. Det. Bernh. /Chicago N. H. Mus. M. Bernhauer Collection (2M, FMNH). Ecuador: Pichincha Prov., 15 km E Sto. Domingo, Tinalandia. 23– 26.II. 1981. 700 m, H. F. Howden (1M, CNC). Same date, except: 26.II.1981 (1F, CNC). 41900/Buckley/ Equador Macas/Fry coll. 1905. 100/Chicago N. H. Mus. M. Bernhauer Collection (1M, FMNH).

ETYMOLOGY: H. basiniger is named to refer to the obvious distinction from H. puncticeps , the black base of the fifth visible abdominal segment.

Figures

Figs. 1–2. Heterolinus spp. 1) H. xanthogaster Solsky; 2) H. basiniger n. sp. Scale

Fig. 19. Geographical distribution of the Heterolinus species. Circles = H. basiniger; triangles = H. puncticeps; squares = H. xanthogaster (question mark indicates locality not identified on map).