Omolabus spinipectus Hamilton

HAMILTON, ROBERT W., 2005, Omolabus Jekel in north and central America (Coleoptera: Attelabidae), Zootaxa 986 (1), pp. 1-60 : 10-11

Omolabus spinipectus Hamilton , new species

( Figs. 1 , 9 , 25, 26, 27 & 28)

Type locality. Costa Rica, Osa Peninsula.

Type holder. Institute of Biological Diversity, Costa Rica ( INBC).

Type material. The type series consists of 28 specimens. The holotype male is labeled as follows: Puntarenas Prov., Osa Peninsula, 2.5 mi. SW Rincon, 6­iii­1967, 0 8°42'N 83°29'W, at Dipterodendron costaricense , HA Hespenheide. The allotype female is labeled the same as the holotype. The sex and label data of the paratypes are as follows: 1 male [dissected] & 2 females (same as primary types); 6 males & 14 females (same as primary types but without host plant label) ( CHAH); 1 male, Prov. Puntarenas, R. Priv. [private reserve] Karen Morgensen, Alred Estacion [near Jicaral], 5 Jul 2003, 320– 350 m, Libre, W Porras, MA Zumbado ( INBC). 1 male & 1 female, Guanacaste Province, Guan. Playas, Nosara, Asent. Financiera, A. C. Guanacaste, m 27–30 Oct 1993, R Vargas & D Brenes ( RWHC).

Size range. Male: 2.3 x 1.1 mm to 3.1 x 1.5 mm; Female: 2.7 x 1.4 mm to 3.2 x 1.7 mm.”

Description. Body reddish­brown to blackish­brown, shiny. (Major male): Head weakly conical widest at base, without punctures except few along margin of eyes, with pair of postocular denticles; vertex weakly flattened; frons bisulcate; sulci diverging into vertex; eyes not or only very slightly protruding from surface of head. Rostrum subequal in length to head, with coarse punctures throughout, twice as wide as frons at apex; postlabial area with slightly protruding smooth transverse ridge. Antennae inserted near basal ¼ of rostrum; club elongate­compact, slightly shorter than funicle; terminal and middle segments nearly subequal in length; basal segment slightly longer; funicular segment 1 ovoglobose, slightly shorter than scape; 2, 3 and 4 subequal, clavate; 5, 6 and 7 subequal, more or less moniliform. Pronotum very robust, widest through middle, rugosely punctured throughout; sides arched out; interspaces forming oblique line­like rugosity; middorsal anterior edge with blunt forward projecting denticle; with small antero­lateral denticle and pair of widely separated antero­ventral spine­like “chest” denticles; anterior collar distinct, dorsally widened and v­shaped. Scutellum distinctly wider than long, 5­sided, posterior margin with distinct angle at middle, with some very small shallow punctures. Elytra as wide as long, widest across humeri, in dorsal view only slightly narrowed posteriorly; not depressed behind scutellum; humeri simple, protuberant; striae small, distinct throughout, forming narrow line­like channels from base to declivities; intervals wide, weakly convex from base to declivities. Profemora evenly swollen. (Minor male): Head with weakly developed denticles; rostrum shorter than head, postlabial area weakly tuberculate; pronotum moderately robust, with “chest” denticles and middorsal anterior denticle weakly developed or indistinct. (Female): Head without denticles; rostrum slightly shorter than head, width at apex more than twice as wide as frons, without postlabial armature; antennae inserted just behind basal ¼ of rostrum; pronotum not robust, without denticles, with weak antero­lateral denticle; profemora evenly swollen.

Distribution ( Fig. 1 ).This species is known only from the Costa Rican provinces of Guanacaste and Puntarenas.

Comments. Omolabus spinipectus is recognized by the small size and coarsely punctured pronotum (Figs. 25–28). The pronotum in this species also differs from the other species of Omolabus in being widest just before the middle and narrowed at the base. The males exhibit unique sexual dimorphism in the paired denticular projections on the head and “chest” area of the pronotum (Figs. 25 & 26). It is closely related to Omolabus (Thyreolabus) piceus (Germar) and Omolabus (Thyreolabus) thoracalis Voss from South America.

Host plants. Most of the type specimens are labeled as taken from Dilodendron costaricense (= Dipterodendron costaricense ) in the family Sapindaceae .

Name derivation. The species name is in reference to the chest” denticles in the male.

Figures

FIGURES 1 – 8. Distribution of Omolabus species: 1) Omolabus veracruensis (square), Omolabus spinipectus (circle), Omolabus megalomus (triangle), Omolabus fasciventris (open triangle) 2) Omolabus ligulatus (circle), Omolabus quadratus (open triangle) 3) Omolabus heterocerus (triangle), Omolabus angulipennis (circle) 4) Omolabus laesicollis 5) Omolabus corvinus 6) Omolabus sedatus (circle), Omolabus longiclava (triangle) 7) Omolabus callosus 8) Omolabus conicollis.

FIGURES 9 – 14. Male genitalia of Omolabus species, 64 X: a) tegmen, dorsal view b) median lobe with endophallic sac and transfer apparatus in repose, ventral view 9) Omolabus spinipectus, Costa Rica, Puntarenas 10) Omolabus quadratus, Panama, Pina 11) Omolabus laesicollis Mexico, Guerrero 12) Omolabus angulipennis, Costa Rica, Puntarenas 13) Omolabus corvinus, Mexico, Quintana Roo 14) Omolabus ligulatus, Honduras, Tela.