Orthorhinus Schoenherr, 1825

Kuschel, Guillermo, 2008, Curculionoidea (weevils) of New Caledonia and Vanuatu: Basal families and some Curculionidae, Mémoires du Muséum national d'Histoire naturelle 197, pp. 99-250 : 197-198

Orthorhinus Schoenherr

Orthorhinus Schoenherr, 1825: 582 (type species Curculio cylindrirostris Fabricius ). — Schoenherr 1826: 223. — Lacordaire 1863: 450, 462.

DESCRIPTION. — Elytra parallel-sided, distinctly wider than prothorax, with rectangular shoulders and distinct humeral callus; odd interstriae costate or tuberculate, usually with one or more tufts of erect setae. Tooth on hind femora not larger than on middle femora, not ciliate, crenulate or denticulate; fore tibiae strongly compressed, with sharp dorsal edge; hind tibiae nearly straight, lower edge not incurved, lacking an expansion or tooth before apex; premucro small or indistinct. Fore coxae disjunct; mesepisternum not prominent, not tuberculiform, with moderately deep impression on sutural area with epimeron.

Male: tegmen (Fig. 146) with widely separate, moderately long parameral lobes, lacking a tooth between them. Aedeagus (Fig. 147) about as long as ventrites 2-5 combined; pedon elongate-elliptic, with small area on either side of apex distinctly paler; sides of pedon, in lateral view, with a long, pale, slit-like line or stripe between ventral surface and a deeply pigmented line halfway up the sides; basal sclerite of internal sac a long, spirally coiled flagellum exposed between apodemes; ejaculatory duct well-pigmented all the way from its origin; median sclerites fused to a large plate bowed over the tip of flagellum, the plate having two long thin processes on anterior angles.

Female: sternite 8 with broad arms, with apodeme rather short, about as long as blade (Fig. 150). Hemisternites at apex dorsally rounded, ventrally obliquely truncate, with long styli; bursa elongate-elliptic, nearly as long as sternite 8, entirely membranous; spermathecal extension arising from inner angle of spermatheca in roughly right angle to stem, with a bulbous expansion at end; duct emerging from the bulbous area, uniformly thick or thickening towards bursa, variable in length from much less than that of bursa to more than twice the bursal length, inserting near base or middle (Figs 151, 152).

DISTRIBUTION. — Philippines, New Guinea, Australia (incl. Lord Howe I.), New Caledonia, Vanuatu.

HOSTPLANTS. — Individual species do not seem to be host-specific and seem to be able to invade a good range of freshly dead or stressed woody plants.

ETYMOLOGY. — ‘Orthorhínus’ is a latinised Greek compound meaning ‘straight nose’.

REMARKS. — To Orthorhinus as defined above belong: O. aspredo Pascoe , O. carbonarius Pascoe , O. cruciatus Montrouzier , O. cylindrirostris (Fabricius) , O. klugi Boheman , O. laetus Saunders & Jekel , O. lateralis Pascoe , O. leseleuci Saunders & Jekel , O. palmaris Pascoe , O. rugosus Montrouzier , O. simulans Boheman , O. tenellus Pascoe , O. variegatus Saunders & Jekel. There are about twenty names referring to members of this genus but some species are ill-defined and require revision.

Two species occur in New Caledonia and Vanuatu. They are keyed out below, together with a closely related species from Woodlark, Entrecasteaux Is. These species have few granules on even interstriae, and lack a tuft of setae on interstria 5 at top of declivity.

KEY TO SPECIES OF ORTHORHINUS OF NEW CALEDONIA, VANUATU, WOODLARK

1. Apical margin of pronotum with a pair of distinct tufts of squamiform setae. 13.0- 15.5 mm. Woodlark ............................................................................................................................................................ [ rugosus ] — Apical margin of pronotum lacking such tufts .......................................................................................... 2

2. Raised interstria 3 with a tuft of squamiform setae beyond middle. Preapical callus on elytra distinct. Elytra with pale, imbricate scales on suture behind scutellum. Tooth on fore femora short, broad (Fig. 143). 8.5-18.5 mm. New Caledonia, Loyalty ................................................................ cruciatus — Raised interstria 3 lacking a tuft of squamiform setae beyond middle. Preapical callus on elytra obsolescent or obsolete. Elytra not noticeably pale behind scutellum, where scales all or most not imbricate. Tooth on fore femora long, narrow (Fig. 144). 8.0- 16.5 mm. Vanuatu..................... leseleuci