Microcryptorhynchus spinifer, Zimmerman, 1942

Zimmerman, Elwood C., 1942, Curculionidae of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 73-146 : 117-118

27. Microcryptorhynchus spinifer , new species (pl. 3, F).

Derm dull to moderately shiny black, with antennae, tarsi and distal ventrite reddish, densely clothed with a thin or thick, hard, amorphous, mudlike incrustation which will soften in water; setae white or grayish white.

Head completely concealed from above by pronotum; finely and densely punctate; with a single row of erect spatulate setae continued from rostrum along inner margins of eyes and converging on crown. Rostrum encrusted and with lateral rows of erect spatulate setae continued to, but becoming finer near antennae, with an additional, short incomplete row of finer setae on either side of median line near end of encrusted and setose area in both sexes, incrustation and setae not extending quite so far from base in female. Prothorax slightly longer than broad (2.3: 2), rounded on sides from base to slightly beyond middle thence conspicuously constricted, constriction continued prominently and deeply across dorsum but true depth usually concealed by incrustation, longitudinal dorsal contour conspicuously sinuate; puncturation coarse, dense, and rough, but individual punctures not large, basal squamose area modified into a sub-hemispherical, almost perpendicular face between basal spines of elytra; disk with long, erect, almost straight, but slightly clavate, spikelike scattered setae and with two rows of similar setae at dorsal apical margin, setae similar to those on elytra and about as long or longer than greatest breadth of a fore tibia. Elytra more than half as broad as long (2.5: 4.0), twice as long as prothorax, true outlines sometimes obscured by incrustation, ovate, arcuate from base to apex, without a subapical constriction; base with a very conspicuous, conical, sharply pointed, sclerotized spine about as long as setae and inclined at about 45 degrees toward the side and centered at third interval, but base extending to or near second and fourth intervals; striae co'arse, broader than intervals, their punctures coarse, deep, subquadrate, close, their interstices narrower than their lengths; intervals convex, only alternate ones bearing rows of very long, conspicuous setae similar to those on pronotum. Legs with femora and tibiae bristling with long erect setae, some of those on outer edges of tibiae about as long as breadth of a tibia; tibial uncus well developed throughout. Stermmi with mesosternal receptacle deep and cavernous, terminating at about middle of mesocoxae in male, and very near hind margins of mesocoxae in female, walls complete but not or but slightly elevated; metasternum between mid and hind coxae slightly shorter than breadth of a mesocoxa, finely punctate, metacoxae separated by about twice median length of metasternum. Venter with first two ventrites flattened in both sexes, densely punctate, but punctures not large, intercoxal process slightly arcuate; fifth ventrite coarsely reticulately minutely punctate or evidently impunctate. Length, 1.5 mm.; breadth, 0.7 mm.

Holotype male, allotype female, and two paratypes from Barrigada , June 12, 1936 and two paratypes from Machanao, one June 12, 1936 and two paratypes from Machanao , one June 4, and June 5 (all collected by Usinger ).

This species is most closely allied to M. basipennis . But it is distinguished from that species by having the basal elytral spines much larger and on the third intervals instead of the second, and by having the dorsal setae longer and more conspicuous. The two species can usually be separated with the unaided eyes because of the <lark muddy incrustation on M. spinifer and the yellowish or whitish incrustation of M. basipennis .