Eugnamptus rostralis Hamilton & Novinger

Hamilton, R. W. & Novinger, A. L., 2004, Eugnamptine weevils of La Selva, Costa Rica (Coleoptera: Rhynchitidae), Zootaxa 610, pp. 1-43 : 30-31

Eugnamptus rostralis Hamilton & Novinger , new species

( Figs. 4 , 16 )

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, Proy. ALAS, INBio­OET, 11 Mayo 2000, FOT/49/01­40, Goethalsia meiantha , INBIOCR1002732048. Allotype female labeled same as holotype except INBIOCR1002732050.

Size range. Male: 3.5 x 1.4 mm; Female: 3.1 x 1.3 mm to 3.5 x 1.6 mm

Description. Male: Head only slightly longer than wide, strongly constricted at base, moderately punctured, distance between punctures subequal to diameter of puncture; eyes very large, strongly protuberant; longitudinal diameter of eye subequal to rostrum in length. gena only ½ as long as ½ the longitudinal diameter of eye; frons narrow, only about ½ width of rostral base. Rostrum subequal to head in length, distinctly widened beyond antennal insertions; width at apex about 3 times width of frons; densely punctured dorsolaterally. Antennae with club longer than funicle; segment 1 of funicle ovo­globose, shorter than scape; segment 2 narrow, subcylindrical; segments 3–6 wider than segment 3, clavate; segment 7 short, beadlike; basal and middle club segments elongate, subequal in length, distinctly longer than terminal segment. Pronotum longer than wide, cylindrical, slightly narrowed anteriorly, with narrow smooth midbasal area; densely punctured; distance between punctures subequal to ½ diameter of puncture. Elytra elongate, parallelsided; striae distinct throughout; intervals weakly convex, as wide as striae; single row of semi­erect setae on strial interspaces; single row of erect setae along intervals; next to last strial row joins last strial row beyond middle. Female: Same as male except rostrum longer than head, with numerous dorso­lateral punctures, distinctly widened beyond antennal insertions; width at apex 1/3 wider than frons; antennae inserted at basal 1/3; frons subequal in width to rostral base.

Color. Male: Head and mid­dorsal strip of rostrum reddish to reddish­brown; antennae and sides of rostrum blackish­brown; pronotum brownish black, elytra blackish brown in basal portion and pale reddish brown in apical portion; front and middle legs yellowishbrown with dorsal apex of femora and tibiae brownish; hind legs yellowish brown throughout; thoracic ventrals and abdominal ventrites blackish brown. Female: Same as male except the elytra can vary from entirely blackish­brown to blackish­brown with two large pale reddish brown areas extending from humeri to near middle ( Fig. 16 d & e).

Comments. The type series consists of 10 specimens. Eugnamptus rostralis can easily be separated from all other La Selva eugnamptines by the color pattern of the body including the reddish head and smooth reddish mid­dorsal rostral strip ( Fig.16 ). The aedeagal pedon is bladelike with a narrowly rounded apex and the TA, although shorter, is similar to that of E. sulcicollis and E. laticeps in having a trifid apex ( Fig.4 b). The majority of specimens were taken by fogging G. meiantha .

Name derivation. The specific epithet is in reference to the diagnostic rostral characters.

Figures

FIGURE 16. Eugnamptus rostralis n. sp.; a – c (male), d – f (female)

FIGURES 1 – 6. Male genitalia, Eugnamptine spp., line = 1 mm. a) Tegmen, dorsal view, b) Median lobe with endophallic sac and TA in repose, ventral view: 1) H. obliteratus 2) E. sulcicollis 3) E. laticeps 4) E. rostralis 5) E. pusillus 6) E. herediensis