Zopherus xestus Triplehorn 1972

Zopherus xestus

DESCRIPTION.—Holotype, sex undetermined. Elongate, moderately robust, dull, velvety black in color. Head entirely black, epistomal margin evenly and deeply emarginate, dorsal surface minutely and very sparsely punctate, punctures not evidently setigerous; ventral surface smooth except for a few feeble punctures on anterolateral margins; mentum transversely trapezoidal, apical margin bisinuate with prominent anterior angles, finely and very sparsely punctate. Pronotum in dorsal view exactly as broad as long, sides strongly and evenly arcuate, with a slight prominence above apex of antennal fossa and five rather prominent tubercles on basal half of lateral margins; sinuate just before base, apical margin broadly and shallowly emarginate, the angles bluntly rounded, basal margin slightly rounded, thickened medially, angles rather sharply rectilinear; surface black except for feeble indications of white or gray lines parallel to and just within lateral borders, very minutely and sparsely punctulate; ventral surface densely opaque with a few small, widely scattered punctures on prosternum; antennal fossae rounded apically. Elytra slightly less than twice as long as broad, sides evenly rounded, base broadly and deeply emarginate, as wide as pronotal base; humeri acute and prominent, basal margin distinctly thickened and reflexed; apical tubercles smooth, shiny, separated from lateral margin by dull ground color and a few small punctures forming a fine groove; sharply separated from raised sutural margin by deep grooves; surface practically smooth, with a series of shallow, irregular, and poorly defined lines producing a wavy pattern over entire surface; very minutely and sparsely punctulate; black in color, with feeble indications of white or gray lines forming a fine network in depressions along lateral border. Mesosternum and metasternum densely opaque, minutely and sparsely punctulate; abdominal sterna likewise sparsely punctate, except on caudal margins of segments 3 and 4 where punctures are more numerous and closely spaced; ventral callus of terminal abdominal sternum trilobed, with the median lobe rounded and prominent, the usual patch of yellowish hair present. Legs coarsely but sparsely punctured.

VARIATION.—The specimen selected as the holotype is almost intermediate in intensity of elytral sculpturing. Some specimens are smoother and show a lesser amount of white on lateral portions of the pronotum and elytra. This I take to be a result of aging and wear. This species is most like laevicollis Solier and is the only one north of the Rio Grande River which has the trilobed ventral abdominal callus and the large flattened tubercles at the apex of the elytra.

MEASUREMENTS.—Holotype: Length 22.4 mm; width 8.2 mm. Paratypes: Length 16.8–24.8 mm; width 6.0–8.8 mm.

SPECIMENS EXAMINED.—Holotype: Brewster County, Texas, Big Bend National Park, The Basin of Chisos Mountains, 8 August 1962, C. A. Triplehorn (OSU). 37 paratypes from same locality, 5 May–3 September, collected by C. A., W. E., B. A., and B. W. Triplehorn, D. J. and J. N. Knull, Howden and Becker, W. R. M. Mason, R. and A. Graves, J. A. Brubaker, R. L. Berry and F. J. Moore, R. and L. Hamilton and Howard V. Weems, Jr., (OSU, CNC, FSCA, RLB, TAM, UCR); (1) Big Bend National Park, Green Gulch (5700′), 24 July 1968, J. E. Hafernik (TAM); (1) Big Bend National Park, Panther Junction (4,000 feet) 29-30 April 1959, Howden and Becker (CNC); (1) Davis Mountains, Jeff Davis County, Texas, 19 June 1958, D. J. and J. N. Knull (OSU).

Zopherus xestus is a species of ironclad beetle in the family Zopheridae. It is found in North America.