Eugnamptus balius Hamilton & Novinger

Hamilton, R. W. & Novinger, A. L., 2004, Eugnamptine weevils of La Selva, Costa Rica (Coleoptera: Rhynchitidae), Zootaxa 610, pp. 1-43 : 36-37

Eugnamptus balius Hamilton & Novinger , new species

( Figs. 10 , 22 )

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, Sep 1993, INBio­OET, 3 Septiembre 1993, Tapirira guianensis , FOT/10/24, INBIOCRI002068506. Allotype female labeled same as holotype except 3 Jul 1993, FOT/07/37, INBIOCRI002069132.

Size range. Male: 3.5 x 1.2 mm to 4.6 x 1.6 mm; Female: 3.8 x 1.2 mm to 4.9 x 1.5 mm.

Description. Male: Head about 1/3 longer than wide, punctures small, widely spaced; gena much shorter than ½ longitudinal diameter of eye; eyes large; longitudinal diameter of eye slightly longer than rostrum; frons narrower than rostral base, with weak median linelike impression. Rostrum 1/3 shorter than head, distinctly widened beyond antennal insertions, width at apex twice as wide as frons. Antennae inserted at middle of rostrum; club distinctly longer than funicle; segment 1 of funicle ovo­globose, shorter than scape; segments 2–6 slender, weakly clavate, subequal in length to scape; funicle segment 1; segment 7 shorter than 2–6, more cylindrical; basal segment of club slightly shorter than middle segment; terminal segment subequal in length to basal segment. Pronotum longer than wide, flattened dorsally, widest at base, moderately punctured; punctures weakly impressed; distance between punctures subequal to ½ diameter of puncture; with a short weak median linelike impression. Elytra almost twice as long as wide; widest at apical third; striae distinct throughout; intervals weakly convex, narrower than width of striae; row of semi­erect setae on strial interspaces; row of erect setae on intervals; next to last strial row joins last strial row near apex. Female: Same as male except rostrum distinctly longer than head, strongly arcuate, width at apex only slightly wider than frons; antennae inserted at basal 1/3 of rostrum; frons slightly wider than width of rostral base.

Color. Head, rostrum and pronotum reddish to orangish brown; elytra paler; each elytron with a blackish brown basal mark; basal marks forming a band across the basal 1/5 of the elytra; each elytron also has near the middle a medial dark mark and a smaller lateral dark spot; antennae brownish­black, terminal club segments paler; thoracic ventrals and abdominal ventrites yellowish brown; tibiae and tarsi blackish brown.

Comments. The type series consists of 11 specimens. Eugnamptus balius is easily recognized by the pale yellowish terminal segments of the antennal club and the dark spots and markings on the elytra. The pedon narrows gradually from the middle to the medially fused bilobate apex ( Fig. 10 b). The TA is similar to that of E. bellus and E. sarapiquensis but has brushlike radiating sclerotizations around the true gonopore. This species was taken in Malaise traps and by fogging V. koschnyi , G. meiantha and T. guianensis .

Name derivation. The specific name refers to the spotlike markings on the elytra.

Figures

FIGURE 22. Eugnamptus balius 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