Rasilinus bifurcatus, Mazur, Milosz A., 2016

Mazur, Milosz A., 2016, A new genus and nine new species of Eugnomini (Coleoptera, Curculionidae) from New Caledonia, ZooKeys 554, pp. 87-118 : 94-97

Taxon classification Animalia Coleoptera Curculionidae

Rasilinus bifurcatus sp. n. Figs 2, 11, 20, 29, 38, 52 ‒54, 78, 87, 99, 101, 108, 115

Diagnosis.

The species can be distinguished from other species by the following combination of features: rostrum short and wide; eyes strongly convex laterally; lateral line of temples longer than length of eyes, distinctly divergent. Last abdominal ventrite apically with two shallow grooves bearing elongate setae. Parameroid lobes of tegmen separate to base. Internal sac of aedeagus with two, elongate, sclerites. Most similar to Rasilinus longulus sp. n. but can be easily distinguished by toothed tarsal claw (unarmed in Rasilinus longulus sp. n.), stronger convex eyes–hw /hl = 1.00 ( Rasilinus longulus sp. n.-hw/hl = ca. 1.20) and shorter rostrum–rl /arw = 1.50 ( Rasilinus longulus sp. n.-rl/arw = 1.70).

Description.

Body length (lb)ca. 3.20 mm.

Body colour and vestiture (Fig. 2). Head, pronotum and elytra dark brown to black; rostrum and legs reddish, apex dark; apical part of tibiae darkening. Antennal scape orange; funicle and club darker. Dorsal surface of rostrum covered with suboval, white scales, middle of rostrum with asetose line. Ventral side of rostrum at base and prosternum covered densely with suboval, white scales. Legs with mixed dark and white elongate scales; hind femora with indistinct transverse stripe composed of small, suboval, white scales.

Head, rostrum and antennae (Figs 20, 29, 38). Head capsule subquadrate (hw/hlca. 1.00). Forehead flat. Eyes convex, strongly protruding dorsally, shorter than half length of head (eyl/hlca. 0.45). Rostrum weakly curved; longer than wide at apex (rl/arwca. 1.50). Funicle shorter than scape; desmomere 1 strongly broadened, ca. 2 × as long as maximal width, as long as 2+3; 2 elongate, longer than 3; 3 longer than wide; 4-7 subquadrate. Club elongate, more than 2 × longer than wide, almost as long as desmomeres 2-7; compact.

Pronotum (Figs 11, 20). Shorter than wide (mpw/plca. 1.20); apical margin straight; base weakly rounded. Widest at middle; anterior half narrower than base. Pronotal disc, when viewed laterally, more sloping towards head than elytra. Surface strongly rough with dense punctation, space between punctures with microsculpture, matt.

Elytra (Figs 11, 20). Widest behind humeral calli, elongate (el/mewca. 1.60), from middle of length strongly narrowed to apex. Dorsal surface slightly shining. Striae with suboval, well isolated punctures, in distal two-thirds of length becoming less numerous towards apex. Intervals weakly convex across whole length.

Legs (Figs 52-54, 78). Front and middle legs elongate; tibiae straight, slender (ptbl/ptbmwca. 5.30). Hind tibiae slender, regularly curved. Front femora glabrous, without tooth; middle femora with small tooth. Claws with obtuse teeth.

Abdomen (Fig. 87, 99). Weakly narrowed, slightly longer than wide at base. Sutures between ventrites 2-5 wide and strongly depressed. Last ventrite almost 2 × wider than long; surface with sparse punctures and elongate setae; lateral margin along two–thirds of length with distinctive, sharp edges, apically with two shallow grooves, each bearing few elongate setae; apical margin widely rounded. Pygidium of male subquadrate, dorsal surface with single, sparse punctures. Ventral processes broad, stout, subquadrate with concentration of elongate setae in the middle and on apical margin.

Male terminalia (Figs 101, 108, 115). Aedegal pedon almost as long as apodemes; regularly narrowed, strongly constricted apically with rounded apex; basal part of pedon completely sclerotised. In lateral view regularly curved with slightly upturned apex. Internal sac with irregular transfer apparatus and two elongate, acute processes. Tegmen with parameroid lobes shorter than apodeme; parameroid lobes completely bilobed, entirely surrounded by membrane; apical part of membrane with distinct, elongate setae. Sternite VIII with elongate, stout apodeme; basal part of apodeme enlarged. Sternite IX with two highly visible, irregular sclerites.

Female. Unknown

Measurements.

Holotype, ♂: apw 0.60; arw 0.30; bew 1.30; bpw 0.75; el 2.15; eyl 0.25; frw 0.20; hl 0.55; hw 0.55; lb 3.20; mew 1.35; mith 0.25; mpw 0.80; mth 0.50; pl 0.65; ptbl 0.80; ptbmw 0.15; rl 0.45; scl 0.60.

Type material.

Holotype, ♂ - 22°11.0'S / 165°17.6'E, Auopinié, 850-900 m., 18.01.2007, forest, leg. M. Wanat & R. Dobosz (MNHN).

Etymology.

From the Latin prefix bi– (two), and noun furca (fork, two-pronged), refers to the two characteristic, elongate sclerites in the internal sac of aedeagus. An adjective.

Distribution.

New Caledonia (main island, north province).