Leptostylus obrienorum, Nascimento & Heffern, 2018

Nascimento, Francisco E. De L. & Heffern, Daniel, 2018, New species of Acanthocinini Blanchard, 1845 (Coleoptera, Cerambycidae) from Rondônia state, Brazil and notes on some genera, Zootaxa 4446 (2), pp. 292-300 : 293-294

Leptostylus obrienorum sp. nov.

( Figs. 1–4 )

Holotype male. Integument reddish brown; mandibles, head (except frons), claws and base of femora dark brown.

Head. Dense yellowish pubescence nearly obscuring integument on frons, reaching area behind eye lobes; with a few elongate erect setae interspersed. Frons longer than wide; median groove conspicuous from frons reaching area behind upper eye lobes; antennal tubercles gradually elevated from median groove. Lower eye lobes as long as genal length. Frontoclypeal suture and labrum with decumbent, elongate yellowish setae. Postclypeus with smooth and glabrous surface. Mandibles with rounded outer margin; basal depression with dense yellowish pubescence. Labial and maxillary palpomere IV fusiform. Upper eye lobes with eight rows of ommatidia; distance between upper eye lobes equal to about width of an upper eye lobe. Antennae 1.5 times body length; reaching elytral apex at middle-length of antennomere VIII; segments I–VII with abundant yellowish pubescence interspersed with irregular spots of brownish pubescence; apex of antennomeres slightly darkened; scape gradually widened towards apex; antennal formula (ratio) based on length of antennomere III: scape = 1.0; pedicel =0.14; IV = 0.90; V = 0.70; VI = 0.55; VII = 0.50; VIII =0.45; IX = 0.42; X = 0.36; XI = 0.33.

Thorax. Prothorax 1.85 times wider than long; middle sides with gibbosities and rhombus tubercle at apex, and small gibbosity anteriorly; pronotum with five elevated tubercles, two at anterior half, three posteriorly, central tubercle less elevated; surface coarsely, irregularly punctate; with abundant yellowish pubescence, nearly obscuring integument; with two small longitudinal areas of brownish pubescence on each side of anterior margin, and two on posterior margin (more distant than those on anterior margin). Prosternum with moderate whitish pubescence; prosternal process 0.7 times procoxal cavity diameter; procoxal cavity closed behind. Meso- and metaventrite with abundant whitish pubescence, not obscuring integument; mesanepisternum and mesepimeron with yellowish pubescence. Mesoventral process about 1.1 times mesocoxal cavity diameter; metathoracic discrimen reaching anterior margin of metaventrite. Scutellum about three times wider than long, with yellowish pubescence. Elytra. Length about 4.5 times prothoracic length; parallel-sided at anterior two-thirds, gradually convergent toward apex; apex obliquely truncate; humerus slightly prominent, rounded; longitudinally sulcate along suture; surface coarsely punctate; base of each elytron with small callosities organized in three rows, remaining areas with small callosities interspersed; elytral pubescence as follows: anterior third with oblique shallow depression covered by dark-brown pubescence, forming an extended "U"; posterior half with transverse bands of cream pubescence, wider toward suture and forward; sub-triangular brownish area centrally placed at the apical fifth, wider toward suture and posteriorly, not reaching the middle of each elytron; area posterior to the subtriangle, with whitish pubescence, following near the suture towards the apex; posterior fifth with dark-brown triangle-shape area at sides, wider near epipleura. Epipleura with dark-brown areas interspersed; remaining areas with yellowish pubescence. Legs with moderately abundant whitish pubescence not obscuring integument; femora pedunculate and abruptly clavate, transversely truncated at apex; tibiae with whitish pubescent band at middle, proximal and distal thirds with dark-brown pubescence. Tarsomere II slightly shorter than I and III; V longer and strongly widened.

Abdomen with whitish pubescence not obscuring integument, irregular spots of brownish pubescence interspersed. Abdominal ventrite I, from intercoxal process, about 2.5 length of II; II–IV slightly decreasing in length; V trapezoidal, apex slightly notched, with dense yellowish elongate erect setae at margin.

Dimensions (in mm), holotype male. Total length, 13.8; prothorax length, 2.4; greatest width of prothorax, 4.2; anterior width of prothorax, 3.3; posterior width of prothorax, 3.5; humeral width, 5.6; elytral length, 10.3.

Type material. Holotype male from BRAZIL, Rondônia: Ariquemes (62 Km SW), 6–12.X.1993, C.W. & L.O’Brien col. ( MZSP).

Etymology. Named of honor of Charles and Lois O’Brien, the collectors of this new species.

Remarks. By the prothoracic shape, and pubescence pattern of the body, Leptostylus obrienorum sp. nov. is similar to Leptostylus bruesi Fisher, 1942 ( Figs. 5–8 ). The new species differs by the small and convex central tubercle of the pronotum, absence of conical tubercles on dorsal area of the posterior half of the elytra, smaller triangular area of the posterior quarter of the elytra, and posterior fifth of the elytra concolorous to the remaining areas of the elytra. In L. bruesi , the central tubercle of pronotum is elevated and conical ( Fig. 6 ), the dorsal area of the posterior half of the elytra have conical tubercles (spine-shaped) throughout ( Fig. 5 ), the posterior triangular area of the elytra occupies almost the entire posterior quarter and the posterior fifth is clearer than the remaining areas ( Fig. 5 ). In addition to the morphological differences, L. bruesi is registered only for Jamaica, while Leptostylus obrienorum sp. nov. is from Brazil (Rondônia).

Figures

FIGURES 1–8. 1–4, Leptostylus obrienorum sp. nov., holotype, male: 1, dorsal view; 2, ventral view; 3, lateral view; 4, frontal view. 5–8, Leptostylus bruesi Fisher, 1942, holotype female (photos taken from: http://insects.oeb.harvard.edu/mcz/): 5, dorsal view; 6, lateral view; 7, frontal view; 8, labels.