Choerorrhinodes flavisetosus, Zimmerman., 1942

Zimmerman, Elwood C., 1942, Curculionidae of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 73-146 : 124-125

32. Choerorrhinodes flavisetosus , new species (pl. 4, F).

Male: derm dull reddish brown, to black, appendages paler, dorsum piceous; setae conspicuously golden yellow.

Head without a constriction behind eyes, sides evenly arcuate from base to eyes, dorsum strongly convex, coarsely reticulate, almost entirely impunctate and bare from base to a line just back of eyes, thence densely, rather coarsely punctate, the stout golden setae somewhat more condensed along inner margins of eyes and across top of punctate front; interocular area twice as broad as an eye as viewed from above, dorsal outline straightly continuous with that of rostrum; eyes separated from prothorax by only about longitudinal diameter of an eye. Rostrum slightly arcuate below, almost straight, straight above almost to antennae, thence gently arcuate, about three fifths as long as pronotum, hardly narrowed on sides from base to antennae, appearing slightly, rather evenly expanded from base to apex, greatest apical breadth only about one eighth broader than narrowest post-antenna! breadth; coarsely reticulate, puncturation mostly similar to that on interocular area, but becoming shallower and less definite distally, with a few scattered golden setae; antennae inserted at middle but appearing more apically inserted because of scrobe being continued past insertion; scrobes deep and well defined to near fore margin of eyes, evanescent behind and without a posterior delimiting carina. Antennae with scape stout, reaching to hind margin of eye; first funicular segment about one third broader than 2, about as long as 2 plus 3, 2 longer than 3, 3 less bulky than 4 or 5, 3 to 5 successively larger and more transverse; club stoutly oval, as long as four preceding segments. Prothorax as broad as long, broadest at about basal third, strongly rounded on sides, most strongly so in basal third from truncate base to strongly marked subapical constriction, constriction only slightly impressed across otherwise slightly arcuate, somewhat flattened longitudinal dorsal contour; apex slightly, broadly emarginate; coarsely reticulate; disk densely punctate, punctures moderately large, but shallow, their interstices narrower than their diameters; most of punctures bearing coarse, decumbent, medially directed, golden setae. Elytra coarsely reticulate, twice as long as broad, somewhat more than twice as long as prothorax; base subtruncate, subparallel-sided to apical third, thence broadly rounded to apex; striae mostly rather shallow and not sharply margined, narrower than intervals, their punctures comparatively shallow and broader than grooves, bearing minute, hardly discernible setae; outer stria terminating at metacoxa; intervals flat or almost so, punctate, punctures bearing coarse, blunt golden setae, setae very conspicuous, slanting, close set in single rows, about as long as breadth of intervals, with ninth interval becoming more costiform above fourth ventrite and joining third. Legs with femora and tibiae with scattered, decumbent, golden, fine hairlike setae; tibial unci well developed, so formed that their inner margins arise from a point near inner apical angles of tibiae, their inner margins, at least on fore pair, making a continuous concave curve that ends in tooth at inner apical angle, teeth at inner apical angles minute; third tarsal segment deeply bilobed, fourth segment beginning at basal third of third segment. Sternum with prosternum coarsely and densely punctate, interstices narrower than punctures, subapical constriction deeply impressed across apical fourth, distance between fore margin of coxae and apex more than twice that behind coxae, intercoxal process only one third as broad as a coxa; intercoxal process of mesosternum flat, about two thirds as broad as a coxa; metasternum broadly concavely flattened down middle in male, densely, rather coarsely punctured, interstices narrower to almost as broad as punctures, each puncture bearing a decumbent golden seta, median line striaform, impunctate, distance between mid and hind coxae three times length of a metacoxa at trochanter or slightly more than twice as broad as a mesocoxa, metacoxae separated by a distance equal to twice length of a metacoxa at trochanter. Venter with first two ventrites punctate and setose as the metasternum, the first rather deeply and broadly concave in the male; ventrites 3 and 4 finely punctate near fore and hind margins; ventrite 5 densely set with setiferous punctures, convex, but with about apical half semi-circularly impressed and less coarsely punctate. Length, 2.3 mm.; breadth, 0.8 mm.

Holotype male collected at Machanao, June 6, 1936, Usinger .

This species is most distinct from the other species described here because of its conspicuous, golden-yellow setae, less coarsely striated and punctate elytra, non-constricted head, more approximate coxae, different structure of the tibial unci, stouter form and other characters.

When a proper revision of the genera of the Cossoninae is written, or when other revisionary work is done, it might be shown that Choerorrhinodes cannot include this aberrant species, and perhaps a new genus may be erected for it. The non-constricted head, and more particularly the more approximate coxae and the structure of the tibial unci are divergent characters. On the other species of Choerorrhinodes described here, the tibial uncus arises distinctly from the outer apical angle and its inner margin is far removed from the inner apical angle of the tibia and the tibia is more or less straight from the base of the uncus to the tooth at inner apical angle. On this species, however, the uncus, although originating as an extension of the outer tibial margin, is so broad at the base and so curved that it appears to arise from the entire apex itself, rather than from the outer edge, and its inner margin continues on to the base of the tooth at the inner apical angle of the tibia.