Orthosinus laosensis Legalov, 2022

Legalov, Andrei A., 2022, Orthosinus laosensis Legalov, a new species of the tribe Strombocerini (Coleoptera: Curculionidae) from North-eastern Laos, Ecologica Montenegrina 51, pp. 15-18 : 16-17

Orthosinus laosensis Legalov , sp. nov.

http://zoobank.org/ urn:lsid:zoobank.org:act:AA104A73-090D-4478-A8E7-75E5F06BB6DD

( Fig. 1 )

Type material: Holotype, male ( ISEA), NE Laos, Hua Phan Prov., Phu Phan Mountains, 1200-1600 m, 10- 22.V.2011, 20°12′N, 103°59′E, St. Jakl . Paratypes: 2 females ( ISEA), idem .

Description

Male. Body black, with matted yellowish pubescence. Antennae, uncus and tarsi brownish. Head subconical. Mandibles small. Rostrum quite short, about 0.9 times as long as pronotum, about 3.3 times as long as wide at apex and at midlength, 3.2 times as long as wide at base, weakly curved, densely punctate. Apex of rostrum almost smooth. Eyes large, coarsely faceted, not protruding from contour of head, suboval, transverse, widely separated beneath. Forehead flat, 0.6 times as narrow as rostrum base width. Antennal scrobes directed ventrally to base of rostrum. Antennae inserted in middle of rostrum. Scape quite long, about 4.3 times as long as wide in apex, not reaching eye. Funicle 6-segmented. Antennomere 2 subconical, 1.5 times as long as wide in apex, 0.2 times as long as and 0.7 times as narrow as scape. Antennomere 3 long-conical, 1.1 times as long as wide in apex, 0.7 times as long as and 0.9 times as narrow as antennomere 2. Antennomeres 4-6 subequal in width. Antennomeres 4-7 wide-conical. Antennomeres 4 and 5 subequal in length. Antennomere 4 0.7 times as long as wide in apex, 0.8 times as long as and 1.3 times as wide as antennomere 3. Antennomere 5 0.6 times as long as wide in apex, 0.8 times as long as antennomere 4. Antennomere 6 equal to antennomere 5. Antennomere 7 about 0.5 times as long as wide, 1.2 times as wide as antennomere 6. Antennal club compact, obliquely truncate, 1.4 times as long as wide, slightly shorter than antennomeres 2-7 combined, with tomentose apex. Pronotum campanulate, 1.7 times as long as wide at apex, 1.1 times as long as wide at midlength and at pronotal base. Pronotal disk weakly convex dorsally, quite sparsely punctate, without carina in middle. Intervals between points subequal to their diameter. Sides subparallel. Base of pronotum 0.9 times as narrow as base of elytra. Scutellum small, suboval. Elytra suboval, evenly rounded at apex with rounded sides, at base 1.5 times as long as wide, at midlength 1.3 times as long as wide, at apical fourth 2.3 times as long as wide, 1.7 times as long as pronotum. Humeri smoothed. Elytral striae distinct. Stria 9 short, fused with stria 10 at level of metacoxae. Interstriae weakly convex, 2.0- 2.4 times as wide as striae, with small pilose pustules. Prosternum punctate. Precoxal portion of prosternum slightly shorter than procoxal cavity. Postcoxal portion of prosternum 0.4 times as long as precoxal portion. Procoxal cavities contiguous. Mesocoxal cavities narrowly separated. Metanepisternum absent. Metaventrite 0.7 times as long as length of metacoxa, flattened, coarsely punctate. Abdomen weakly convex ventrally, punctate. Ventrites 1 and 2 concave in middle. Ventrite 1 0.7 times as long as length of metacoxa. Ventrite 2 1.1 times as long as ventrite 1. Ventrite 3 about 0.3 times as long as ventrite 2. Ventrite 4 equal to ventrite 3. Ventrite 5 convex, with impression before apex, 3.4 times as long as ventrite 4, coarsely punctate. Pygidium almost vertical. Procoxae subconical. Mesocoxae spherical, narrowly separated. Metacoxae almost spherical. Femora slightly thickened, without tooth. Tibiae weakly curved, with large uncus. Tarsi long. Tarsomeres 1- 3 conical, with erect setae ventrally. Tarsomere 5 elongate. Tarsal claws free, divergent. Total body length (without rostrum) 5.1 mm. Length of rostrum 1.35 mm.

Female. Rostrum quite short, about 0.8 times as long as pronotum, 3.6-3.8 times as long as wide at apex and at midlength, 3.2 times as long as wide at base. Pronotum 1.7-1.8 times as long as wide at apex, 1.1 times as long as wide at midlength and at pronotal base. Elytra at base 1.6-1.7 times as long as wide, at midlength 1.4-1.6 times as long as wide, at apical fourth 2.3-2.4 times as long as wide, 1.6-1.7 times as long as pronotum. Total body length (without rostrum) 4.9-5.3 mm. Length of rostrum 1.3-1.6 mm.

Differential diagnosis. The new species differs from O. direptus ( Marshall, 1931) in the longer and narrower elytra, wider elytral interstriae and not coarsely punctate pronotum with subparallel sides. It is distinguished from O. tuberculatus Legalov, 2021 in the suboval elytra without large pilose pustules, and the pronotum longer than wide.

Etymology. From Laos.

Localisation. Laos, Hua Phan Prov.

Figures

Figure 1. Orthosinus laosensis sp. nov. a – holotype, male, dorsal view; b – paratype, male, dorsal view; c – holotype, aedeagus, dorsal view; d – holotype, male, lateral view. Scale bar = 1.0 mm for a, a, d, 0.5 mm for c.