Eugnamptus longiusculus Hamilton & Novinger

Hamilton, R. W. & Novinger, A. L., 2004, Eugnamptine weevils of La Selva, Costa Rica (Coleoptera: Rhynchitidae), Zootaxa 610, pp. 1-43 : 33-34

Eugnamptus longiusculus Hamilton & Novinger , new species

( Figs. 7 , 19 )

Type designation. Holotype male with the following label data: Costa Rica, Heredia: Est. Biol. La Selva, 50–150 m, 10°26'N 84°01'W, 2 Sept 1993, INBio­OET, M/15/205, INB0003645845. Allotype female labeled same as holotype except 29 Sept 1995, M12/ 469, INB0003645844.

Size range. Male: 3.4 x 1.2 mm to 5.0 x 1.6 mm; Female: 4.6 x 1.6 mm to 5.3 x 2.0 mm.

Description. Male: Head longer than wide; punctures small widely spaced; gena subequal to ½ longitudinal diameter of eye; longitudinal diameter of eye distinctly shorter than rostrum; frons wider than base of rostrum, weakly concave, with weak longitudinal linelike impression. Rostrum shorter than head, slightly widened beyond antennal insertions; width a apex subequal to width of frons. Antennae inserted at middle of rostrum; club distinctly longer than funicle; segment 1of funicle cylindrical, subequal to scape in length; segments 2–6 subequal in length, more or less clavate, slightly longer and more slender than segment 1; segment 7 shorter than 2–6, more globose; middle segment of club slightly longer than basal segment; terminal segment of club subequal to basal segment in length. Pronotum longer than wide, widest at base, densely punctured; distance between punctures ½ or less diameter of puncture; punctures weakly impressed. Elytra longer than wide, widest at apical 1/3; striae distinct throughout, smaller posteriorly; intervals weakly convex, subequal in width to width of striae; single row of semi­erect setae associated with strial interspaces; single row of widely spaced erect setae along intervals; next to last strial row joins last strial row near or at apex. Female: Same as male except rostrum distinctly longer than head; width at apex narrower than width of frons; antennae inserted at basal 1/ 4; frons distinctly wider than width of rostral base.

Color. Male: Body yellowish to orangish brown throughout; antennae blackish brown; femoral apices and tibiae blackish brown. Female: Same as male except legs are orangish brown throughout.

Comments. The type series consists of 10 specimens. Eugnamptus longiusculus can be recognized by the overall reddish­orange to reddish­brown color, the dark antennae and variably darkened legs. This species is very similar to E. divisus Sharp in color pattern but seems to differ in punctuation. The parallel­sided pedon is very elongate and strongly narrowed in the apical 1/4 into a narrow minutely bidentate apex ( Fig. 7 b). The TA is unique in this species. It is rounded in the middle with a clear area and two narrow elongate parallel struts extending basally and distally from the middle. Eugnamptus longiusculus was taken only in Malaise traps.

Name derivation. The specific name is derived from the Latin root meaning “long” and is in reference to the elongate aedeagus.

Figures

FIGURE 19. Eugnamptus longiusculus n. sp.; a – b (male), c – d (female).

FIGURES 7 – 12. Male genitalia, Eugnamptine spp., line = 1 mm. a) Tegmen, dorsal view, b) Median lobe with endophallic sac and TA in repose, ventral view: 7) E. longiusculus 8) E. bellus 9) E. sarapiquensis 10) E. balius 11) E. suturalis 12) E. basalis