Ataenius sculptor Harold 1868

Ataenius sculptor Harold

Ataenius sculptor Harold, 1868:85.—Schmidt, 1922:426.

Ataenius oblongus Horn, 1871:286; 1887:81.—Schmidt, 1922: 426. [New synonymy.]

DESCRIPTION.—Length 5.2 to 6.1 mm; width 2.4 to 2.6 mm. Elongate-oblong, moderately convex, shining, black, clypeal margin and legs slightly reddish. Head only moderately convex, finely reflexed anterior clypeal margin broadly rounded each side of wide, moderately deep median emargination, sides weakly arcuate to nearly right-angled genae; clypeal surface smooth, shining, narrowly concave at middle along anterior margin; densely punctate over remainder of clypeus and front, minutely punctate along smooth anterior margin but very quickly becoming moderately coarse, a little smaller over median convexity, very dense and a little larger between middle and genae, very moderate along edge in front of the eye. Pronotum approximately two-thirds as long as wide, sides and base margined, minutely fimbriate-crenate under moderate magnification, the setae extremely short and widely spaced, very inconspicuous, anterior angles very obtusely rounded, sides practically straight, hind angles slightly emarginate, base not quite evenly arcuate; surface closely, coarsely punctate everywhere except along anterior margin where the punctures are gradually finer, separated on disc by one diameter generally, very dense laterally. Elytra approximately two-thirds as wide as long, humeri strongly, sharply dentate, sides slightly but noticeably arcuate, striae strong and deep, strial punctures crenating inner sides of intervals, the strial punctures separated by about five times their diameters; intervals on disc moderately convex, laterally more carinately convex, with a row of very noticeable, moderate, minutely setigerous punctures along each margin of the interval, closer on outside edge on disc and very close on both sides on lateral intervals, 10th interval flat, alutaceous, with a median row of small, close, shiny tubercles; shoulders closely moderately punctate; striae becoming wider and the intervals carinately convex with narrow alutaceous shoulder over the apical declivity. The alutaceous shoulders are traceable forward as very thin marginal lines to near the middle of the elytra. Mesosternum shagreened as in most species, finely carinate between coxae. Metasternum with long, fine, rather shallow midline, disc densely, moderately coarsely punctate, the punctures extending outward to wide, scabrous area at sides, metasternal triangle rather shallow, finely scabrous within. First visible abdominal sternum with rather wide, alutaceous, posterior marginal lines. All remaining sterna fluted along anterior margin, the fluting of the first very fine, of the next quite long, of the 4th sternum very wide and long and longer at sides, those of the 5th sternum at middle as long as at sides on 4th; surface of the two widest sterna convex, densely punctate from side to side, very moderate in front to moderately coarse along posterior where they almost touch and form a marginal line; punctures of 4th sternum more moderate in size with marginal row very close and smaller; punctures of 5th sternum close and a little smaller, with an alutaceous groove along outer third of posterior margin. Pygidium with shining, finely, closely punctate apical lip, the disc rough and unusually deeply eroded. Anterior femora with perimarginal groove, surface densely, scabrously punctate. Middle femora densely, moderately punctate with three or four coarse setigerous punctures at knee and complete, strong posterior marginal line. The posterior femora as in the middle femora but the punctures not dense, separated by one to two diameters, posterior line strong, deep, and complete. Posterior tibial apical fringe of eight short, close, heavy setae, a very strong accessory spine, and an intervening seta between spine and spurs. Long spur about one-fourth shorter than the very long metatarsus which is as long as the following four segments combined. The 4th and 5th sterna are relatively shorter and the pygidium longer in the male.

nocturnus ● gracilis

HOLOTYPE.—In Harold collection, Muséum National d’Histoire Naturelle. [Type of A. oblongus Horn in the Leconte Collection, Museum of Comparative Zoology, No. 8097.]

TYPE-LOCALITY.—Colombia. [Type-locality of oblongus: California.]

SPECIMENS EXAMINED.—Two, plus numerous Mexican specimens.

DATES COLLECTED.—August 17 to September 21, in Mexico.

DISTRIBUTION (Figure 20).—Arizona: Nogales. California: “California.”