Eugnamptus suturalis Sharp

Hamilton, R. W. & Novinger, A. L., 2004, Eugnamptine weevils of La Selva, Costa Rica (Coleoptera: Rhynchitidae), Zootaxa 610, pp. 1-43 : 37-38

Eugnamptus suturalis Sharp

( Figs. 11 , 23 )

Eugnamptus suturalis Sharp, 1889: 38

Type locality. Panama

Type holder. BMNH

Lectotype designation. The male and female syntypes are card mounted. The male bears the following label data: Eugnamptus suturalis D.S., Boquete, Panama, Volcan de Chiriqui, Boquete, Caldera and Champion, B.C.A. Col. IV. 3. Eugnamptus suturalis Sharp , Syntype [label with blue border]. The female is labeled as follows: Eugnamptus suturalis Type D.S., Boquete, Champion, Type, Panama, Volcan de Chiriqui, Boquete, Caldera and Champion, B.C. A. Col. IV. 3. Eugnamptus suturalis Sharp , Syntype. The male is designated as lectotype and the female as allolectotype.

Size range. Male: 3.7 x 1.2 mm to 4.3 x 1.8 mm; Female: 4.0 x 1.4 mm to 4.7 x 2.0 mm.

Description. Male: Head longer than wide, punctures very small, widely spaced; gena shorter than ½ longitudinal diameter of eye; longitudinal diameter of eye subequal to rostrum in length; frons narrower than rostral base, with weak median linelike impression. Rostrum shorter than head, slightly widened beyond antennal insertions; width at apex slightly wider than frons; dorso­lateral apex distinctly punctured. Antenna inserted at middle of rostrum; club long, distinctly longer than funicle; segment 1 of funicle ovo­globose, about ½ as long as scape; segments 2–6 slender, weakly clavate, slightly longer than segment 1; segment 7 shorter than segments 2–6, more cylindrical; basal segment of club shorter than middle segment; terminal segment about ½ as long as middle segment. Pronotum longer than wide, widest near middle, moderately punctured; punctures weakly impressed; distance between punctures subequal to ½ diameter of puncture; with linelike median impression. Elytra almost twice as long as wide, widest at apical third; striae distinct and similar 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 just beyond middle. Female: Same as male except rostrum longer than head, more arcuate; rostral apex flattened, with numerous dorso­lateral punctures; antennae inserted near basal 1/3; and frons slightly wider than rostral base.

Color. Head, pronotum, ventrals, and basal two­thirds of femur orangish to orangish brown; elytra blackish brown; each elytron with a complete narrow orangish border; sides of rostrum, antenna, femoral apices, tibiae and tarsi varying from orangish brown to blackish brown; terminal antennal segments in some specimens distinctly pale.

Comments. Sixty­four specimens were examined. Eugnamptus suturalis is recognized by the narrow pale orangish margin that completely borders each dark elytron ( Fig. 23 ). The pedon is parallel­sided and broadly rounded at the apex with two very small rounded median projections ( Fig 11 b). The TA has elongate parallel sided basal struts and is rounded and swollen distally with a clear central area and two closely set forward projecting median spinelike projections. The distally swollen portion of the TA is minutely bristled. This species was collected mainly by malaise traps although some were collected by hand with beating sheets. A single female was beaten from Alchornea costaricensis Pax and K. Hoffmn (Euphorbiaceae) at La Selva and later oviposited in an unattached leaf of Spondias mombin L. The larvae developed to late instars as blotch leaf miners but failed to pupate.

Figures

FIGURE 23. Eugnamptus suturalis Sharp; 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