Macrancylus niger, Zimmerman, 1942

Zimmerman, Elwood C., 1942, Curculionidae of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 73-146 : 141-142

43. Macrancylus niger , new species (pl. 5, F).

Male: derm black, shiny, polished, appendages diluted with red; setae minute, pale, and inconspicuous.

Head as broad across eyes as length of head from pronotum to anterior edges of eyes, conspicuously constricted on sides at or slightly more than the length of an eye, as measured from above, behind eyes, constriction continued broadly across dorsum; area behind constriction almost impunctate, with a few small punctures near constriction only, puncturation beyond constriction continuous with that of rostrum, punctures small and separated by interstices as broad or broader than their diameters; eyes not prominent, extending laterally only one sixth of length of an eye; interocular area almost three times as broad as length of an eye as measured from above, with only an inconspicuous, subobsolete median impression, longitudinal dorsal contour continuous with that of rostrum. Rostrum as long beyond eyes as side of head from prothorax to fore edges of eyes, almost one half as long as prothorax, somewhat more than twice as long as an eye, about as long as basal breadth of rostrum, lateral outlines almost straightly narrowing from hind margins of eyes to apex, narrowest apical breadth bearing a ratio of 13 to 15 with basal breadth; puncturation similar to and continuous with that of front, but becoming finer distally; upper margin of scrobe touching lower margin of eye, lower margin extending back at least as far as middle of eye; antennae inserted at about half length of an eye in front of eyes. Antennae with scape reaching behind eye to cephalic constriction, arcuate; first funicular segment somewhat longer than broad, somewhat longer than 2 plus 3, 2 to 7 transverse and each successively somewhat broader; club compressed, five sixths as broad as long, longer than preceding six segments. Prothora:r longer than broad (3.5: 2.8), base and apex subtruncate, rounded on sides in basal fourth, broadest in basal third thence slightly arcuately narrowing to rather shallow subapical constriction, constriction broadly and shallowly interrupting otherwise evenly, flatly arcuate longitudinal dorsal outline; discal punctures about two or three times as large as those on head, separated by not more than their diameters. Elytra slightly more than two and one third times as long as broad, somewhat more than twice as long as prothorax, subparallel-sided to beyond basal two thirds, outline thence slightly sinuously rounded to apex but not distinctly constricted; striae narrow, deep, well defined, slightly narrower than intervals, their punctures close, well defined, bearing microscopic setae, outer stria narrowed above metacoxa and almost impunctate above first two ventrites; intervals convex, each with a row of minute punctures bearing microscopical setae, first interval widening at apex, and there the right one distinctly broader than the left, and about twice as broad as 2, 1 narrower than 2 on disk, 3 slightly more elevated on declivity than the others, 8 beginning at about posterior fourth of metasternum, 9 costiform behind second ventrite, fused with third and thence joining second at elytral apex. Legs with femora sparsely punctate; tibiae strongly uncinate and mucronate, a mucro about half as long as an uncus, fore pair angulate at middle of lower edge; third tarsal segment hardly broader than second, entire or but slightly emarginate distally, second segment about as long as third; claws strongly divergent. Sternum with prosternum closely punctate throughout, three times as long in front of as behind coxae, intercoxal process about five sevenths as broad as distance between coxa and hind margin of prosternum; mesosternum on same plane as metasternum, closely punctate, intercoxal process one fourth broader than a mesocoxa; metasternum closely punctate throughout, punctures separated by interstices as broad or broader than punctur~s on the disk but narrower than punctures on sides, median line sulcate from in front of middle to apex, not quite four times as long between mid and hind coxae as length of a mesocoxa, suture at mesosternum almost obliterated, metacoxae separated by breadth of a mesocoxa. Ve1iter with first two ventrites shallowly impressed down middle, ventrite 1 with larger and more numerous punctures than 2, 2 mostly sparsely and minutely punctate, 3 and 4 with a row of coarser punctures at their bases and a few smaller scattered punctures; 5 impressed in distal half, with dense punctures similar to those on 1. Length, 2.75 mm.; breadth, 0.75 mm.

Holotype male, Talofofo, May 7, 1936, Usinger .

This species differs from Macrancylus linearis LeConte in being larger and shiny black instead of reddish brown or piceous, by having the prothorax evenly arcuate on the sides instead of sinuous, the head longer behind the eyes with the cephalic constriction deeper, more conspicuous, distinctly impressed across the dorsum and farther behind the eyes, and the prosternum is three times as long in front of as in back of the fore coxae instead of only twice as long.·