Dryotribodes angularis, Zimmerman, 1942

Zimmerman, Elwood C., 1942, Curculionidae of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 73-146 : 135-136

38. Dryotribodes angularis , new species (pl. 5, B).

Male: derm black with a thin greasy incrustation, denuded areas moderately shiny, appendages diluted with red.

Head narrower across eyes than length from pronotum to fore margins of eyes, sharply and deeply constricted on sides at about three fourths length of an eye behind eyes as measured from above, constriction continued deeply and angulately across dorsmn; alutaceous but moderately shiny and impunctate behind constriction, very coarsely, densely, continuously punctate with rostrum beyond constriction; eyes not projecting much beyond lateral margins of head; interocular area hardly broader than breadth of an eye as measured from above. Rostrum continuous in longitudinal dorsal contour with front of head and almost straight in basal half, thence rather strongly arcuate to apex, four times as long as an eye from fore margins of eyes to apex, two thirds as long as prothorax, twice as long as its apical breadth, more than twice as long as its basal breadth, subparallel-sided, but very shallowly, just perceptibly concave from base to antennae, thence expanded and subparallel-sided to apex, the greatest apical breadth about one fifth broader than the narrowest post antenna! breadth; very coarsely, densely, subreticulately, subconfluently punctured throughout; antennae inserted at slightly beyond middle at hardly more than twice length of an eye from eyes. Antennae with scape reaching hind margin of ey~, and not extending to cephalic constriction; first funicular segment about one fourth longer than broad, about as long as 2 plus 3, 2 about as broad as long, slightly longer than 3, 3 to 7 successively broader, 7 almost twice as broad as 2; club slightly longer than five preceding segments. Prothorax distinctly longer than broad (32: 2.5), broadest at and beyond middle, base and apex subtruncate, subequally, prominently, and angulately constricted in front of base and behind apex, subparallel-sided between these constrictions, apex subtubulate beyond constriction, subapical constriction shallowly and broadly impressed across otherwise evenly arcuate dorsum; very coarsely and densely punctured, punctures much broader than their intervals, which when denuded, are shiny; setae inconspicuous. Elytra twice as long as broad, twice as long as prothorax, broadest at middle, arcuate on sides from base to apical fifth and there constricted, apex appearing emarginate on either side at second interval because of elevated ninth interval; striae deep and coarse, obviously broader than intervals, their punctures large, deep, coarse and mostly subquaclrate, outer stria, the eighth connected across base conspicuous and distinct throughout its length to apex; intervals convex, moderately shiny where clenuclecl,2 and 3 appearing most prominent and somewhat more elevated than 1, 4 fragmented and almost obliterated by stria! punctures, 6 not reaching much nearer base than metacoxa, the others not prominent near base, 8 represented by a trace above second ventrite only, 9 strongly elevated above fifth ventrite into a conspicuous, asperate, posterior callosity that reaches second interval at its apex and is separated from apical margin by outside stria; setae minute and inconspicuous. Legs with femora coarsely punctate; tibiae with unci and teeth at inner apical angles well developed; third tarsal segment shortly bilobecl, more emarginate than bilobecl, one third broader than second. Sternum with prosternum coarsely and densely punctured throughout, twice as long in front of as behind coxae, intercoxal process only one third as broad as l coxa; mesosternal intercoxal process slanting upward in front, impunctate, about three fourths as broad as a coxa; metasternum with large, coarse, deep, close-set punctures, almost twice as long between mid and hind coxae as breadth of a mesocoxa, metacoxae separated by about twice breadth of intercoxal process of mesosternum. Venter with first two ventrites broadly concave, puncturation similar to that of metasternum but in part less coarse and deep; ventrites 3 and 4 with their posterior edges slightly crenulatecl with small punctures, otherwise impunctate; ventrite 5 coarsely and densely punctate, but impunctate at base and apex. Length, 2.4 mm.; breadth, 0.75 mm.

Holotype male collected at Yona, from dead leaves, May 29, 1936, Bryan .

In addition to the differential characters given in the key, this species differs from Dryotribodes obsrnrus by having the cephalic constriction deeper and more conspicuous, the prothorax more deeply constricted at base and apex, the ninth elytral interval much more strongly elevated behind thus making the apex of the elytra emarginate on either side, the fore and mid coxae are less widely separated and the third and fourth ventrites are not coarsely punctate across their disks.