Melanoxanthus usingeri, Zwaluwinburg, 1942

Van Zwaluwenburg, R. H., 1942, Elaterid And Eucnemid Beetles Of Guam, Insects of Guam I, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 53-55 : 55

8. Melanoxanthus usingeri , new species.

Slender, generally flavous; head blackish with irregular yellowish area behind anterior margin; antennae more or less uniformly yellowish brown; pronotum with blackish spot near lateral margin behind middle and along middle of disk; on either side anteriorly with ill-defined blackish markings; dusky along suture of elytra almost to apex, the dusky line widening behind middle to cover three intervals on either side (extending very vaguely as far as the 5th interval) thence narrowing regularly to the end of the dusky line along suture; each humerus with a small blackish mark. Body beneath generally yellowish brown, with abdomen darker. Legs light brown. Pubescence yellow; fine, short. Front moderately convex; punctation subumbilicate, uniform; on basal one third a brief, median, cariniform prominence which fails to attain the anterior margin of the pronotum; anterior margin of front broadly rounded. Antennae failing to attain tips of hind prothoracic angles by the length of the last three segments; 3d segment half as long again as 2d, the two together subequal to 4th; 4 to 10 feebly serrate, gradually diminishing in length; 11th elongate oval. Prothora.t" longer than median width; sides arcuately narrowed from base of hind angles to anterior one third, thence more rapidly to anterior margin; moderately convex; basal declivity moderate, not impressed medianly; punctation on disk finer than on head, coarser, subumbilicate toward sides. Hind angles short, blunt; slightly divergent; acutely unicarinate. Mucro briefly upturned behind fore coxae, posteriorly subhorizontal; excavate between coxae. Scutellum sagittate, moderately inclined; convex toward base; coarsely punctulate. Elytra at base as wide as hind prothoracic angles; sides subpa1?allel to about middle, thence conjointly narrowed to apex; apex rounded, entire, not spinulose at sutural angles. Stria! punctures rather fine; intervals flat, subrugose toward base. Female, length 8.0 mm.; width 2.1 mm.

Agat, May 31, ex Pithecolobiunz , Usinger , holotype female .

Its larger size and the triangular widening of the dusky marking along the suture will distinguish this species from the other two described above.