Melanoxanthus guamensis, 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 : 54

6. Melanoxanthus guamensis , new species.

Slender. Generally blackish; head and antennae blackish with two or three basal segments of the antennae sometimes rufous; pronotum blackish or flavous suffused with blackish, but with hind angles always flavous, anterior margin usually flavous; scutellum black; base of elytra flavous, this coloration sometimes distinctly separated from, but usually confluent with, an elongate flavous marking on the basal one half; on posterior one third of elytra a smaller, elongate-oval, flavous spot; suture always black or dusky. Body beneath flavous to blackish; legs flavous. Pubescence fine, semi-erect, fulvous. Front convex on disk, flattened anteriorly; punctation moderately coarse, uniform; anterior margin broadly rounded. Antennae in male barely exceeding, or in female just failing to attain, the tips of the hind prothoracic angles; 2d and 3d segments subequal, together shorter than 4th; 4 to 10 feebly serrate, diminishing in length. Prothorax slightly longer than median width, even in female; sides narrowed from base of hind angles to anterior one third (slightly more arcuately in female than in male), thence more rapidly to anterior margin. Pronotum convex, flattened on disk, lightly punctate, punctures on disk as on head, subumbilicate toward sides; faintly impressed medianly at base. Hind angles stout, acutely unicarinate. Punctation of propleura umbilicate, shallow, sparse, distinctly coarser than on prosternum. Mucro subhorizontal, widely excavate between fore coxae. Srntellmn moderately inclined; flat, elongate, acute behind. Elytra at base narrower than hind prothoracic angies; sides narrowed to middle in female, or beyond in male, thence conjointly narrowed TODO to apex; apex subtruncate, sutural angles finely spinulose. Stria! punctures rather coarse; intervals flat, finely punctulate. Length, males 3.5-3.6 mm.; females 3.75-4.25 mm.

Machanao, June 5, Usinger, holotype male; Inarajan, July 25, on Pithecolobium dulce, Swezey, allotype female; Ritidian Pt., April 15, Bryan, two paratype males; Inarajan, 1\.fay 6, Usinger; Ritidian Pt., June 2, Usinger, three paratype females; Machanao , June 5, Usinger ; Mt. Alifan , June 27, Usinger.

The area occupied by the flavous maculations varies considerably. This species is similar to the Philippine M. vicintts Fleutiaux, but shows the following differences: 1, the base of the elytra is flavous, not black as in M. vicinus; 2, the maculation on the basal half of the elytra is longitudinal, not oblique; 3, the antennae of the male barely exceed, not just fail to attain, the tips of the hind prothoracic angles; 4, the base of the pronotnm is barely impressed medianly, not acutely channelled as in vicinus.