Dryotribus amplioculus, Davis & Engel, 2007

Davis, S. R. & Engel, M. S., 2007, Cossonine weevils in Dominican amber (Coleoptera: Curculionidae), Linzer biologische Beiträge 39 (2), pp. 803-820 : 803-820

Dryotribus amplioculus nov.sp. ( Figs 29-31 )

H o l o t y p e: USNM 505329 (= Woodruff #9778), amber, Dominican Republic, Early Miocene (Burdigalian).

D i a g n o s i s Head distinctly constricted behind compound eyes; compound eyes situated at base of rostrum, bulging and subcircular ( Fig. 29 ). Vertex with a shallow, rounded groove ( Fig. 29 ). Pronotum with large, deep punctures; smaller and more sparse punctures anteriorly. Elytra with approximately 10 striae, with elytral striae small, shallow, and sparsely distanced. Venter heavily punctate. Profemora enlarged; tibiae bearing a large uncus on outer angle ( Fig. 30 ); opposite of uncus at inner angle a smaller, less conspicuous denticle.

D e s c r i p t i o n: Total body length (including rostrum) ca. 1.88 mm; maximal width ca. 0.52 mm; elytral length ca. 0.71 mm (as preserved, apex of abdomen missing). Integument dark brown to black (as preserved). Compound eyes bulging and subcircular ( Fig. 29 ), length approximately equal to width; positioned at base of rostrum; interocular distance approximately equal to width of rostrum in dorsal view. Rostrum puncticulate and slightly longer than length of pronotum; ventral margin moderately curved in lateral view ( Fig. 29 ), with curvature mostly at basal half; rostrum width widened along apical half in dorsal view. Antenna inserted at mid-length of rostrum, scrobe shallow; scape reaching middle of compound eye; scape more or less one-third length of rostrum; funicle narrow, enlarging to a distinct club. Vertex smooth and glabrous, with a shallow depression. Pronotum glabrous, length approximately 1.3✕ width; anterior portion narrower than posterior portion; large, deep punctures present, punctures separated by distance 1-4✕ puncture diameter; punctures smaller and sparser anteriorly; lateral margins broadly rounded. Prosternum without shallow depression between procoxae; large, deep punctures present, punctures separated by distance 0.5-1✕ puncture diameter; coxal positions as in figure 31. Scutellum triangular, small, length slightly less than anterior basal width. Elytra each with approximately 9-10 striae; punctures of elytral striae small and shallow, separated by distance approximately 2-4✕ puncture diameter; humeri rounded. Abdominal ventrites with large, deep punctures present, punctures separated by distance 0.5-1✕ puncture diameterx. Femora clavate and puncticulate; profemora enlarged ( Fig. 30 ); tibiae laterally expanded apically; apical tibial unci at outer angle large, approximately equal or slightly longer than length of tarsomere IV; a small denticle present on opposite side of uncus on inner angle, length equal to or slightly less than pretarsal claw length.

E t y m o l o g y: The specific epithet is a combination of the Latin terms amplio (meaning "enlarge") and oculus (meaning "eye") and is a reference to the large, bulging compound eyes.

C o m m e n t s: This species is differentiated from extant congeners by the shallow depression on the vertex of the head; the relatively large, bulging compound eyes; the distance separating the pronotal punctures; the number of elytral striae; and the distance

809

separating the elytral striae. Other species of Dryotribus have a heavily punctate integument; however, the distance separating the punctures varies between species.

Figures

Figs 29-38: Two species of Dryotribini, Dryotribus amplioculus nov.sp. (holotype, USNM 505329) and Paralicus abnormis nov.sp. (holotype, USNM 505350), and one of Proecini, Proeces longirostrum nov.sp. (holotype, USNM 502728). (29) dorsal oblique aspect of head and anterior pronotum of D. amplioculus; (30) protibia, profemur, protarsus, and pro-pretarsus of D. amplioculus; (31) ventrolateral oblique view of prothorax of D. amplioculus depicting position of procoxae; (32) lateral aspect of head of P. abnormis; (33) dorsal aspect of head of P. abnormis; (34) protibia, profemur, protarsus, and pro-pretarsus of P. abnormis; (35) ventral aspect of prothorax of P. abnormis depicting position of procoxae; (36) Lateral aspect of head of P. longirostrum; (37) protibia, profemur, protarsus, and pro-pretarsus of P. longirostrum; (38) dorsal oblique aspect of head of P. longirostrum. All drawn as preserved.