Coptus vitreous Omar and Zhang, 2017

Davis, Steven R., 2017, Coptus Wollaston (Coleoptera: Curculionidae: Cossoninae): A genus new to China with descriptions of two new species, Zootaxa 4312 (2), pp. 381-393 : 386-390

Coptus vitreous Omar and Zhang sp. nov.

( Figs. 4–6 , 29–38 )

Holotype. ♂. China. Yunnan Province: [ Menglun Botanical Garden [21.55N, 101.15E]; 21 VII 1959; leg. Yiran Zhang. (IOZ)]. Paratype. 1♀, same data as the holotype.

Diagnosis. Body 5.00 mm in length. Rostrum moderately long, broadly curved dorsally after point of antennal insertion (basal half), anterior half flat, nearly parallel-sided, with short median elliptical sulcus at point of antennal insertion. Scrobe triangular, covering basal 2/3 of rostrum until slight distance before anterior margin of eye; point of antennal insertion at basal 1/3 of rostrum. Antennal scape slightly passing posterior margin of eye. Eyes broadly convex, subcircular, with smooth, fine, convex facets. Pronotum shagreened, with sparse, shallow, fine circular punctures throughout, punctures separated by approximately 2– 5 x puncture diameter. Elytral striae with shallow, circular punctures, punctures separated by approximately 1 x puncture diameter or less.

Description. Holotype, male. Measurements: BL: 5.00 mm; EL: 2.64 mm; EWB: 1.05 mm; EWW: 1.05 mm; PL: 1.26 mm; PW: 1.04 mm; RL: 0.70 mm; RWA: 0.45 mm; RWB: 0.42 mm; AL: 1.18 mm; ASL: 0.55 mm; AFL: 0.33 mm; ACL: 0.30 mm; ACW: 0.17 mm. Female. Measurements: BL: 4.50 mm; EL: 2.60 mm; EWB: 1.12 mm; EWW: 1.12 mm; PL: 1.15 mm; PW: 0.99 mm; RL: 0.64 mm; RWA: 0.39 mm; RWB: 0.39 mm; AL: 0.91 mm; ASL: 0.42 mm; AFL: 0.29 mm; ACL: 0.20 mm; ACW: 0.15 mm.

Habitus ( Figs. 4–6 ): small, curved, oblong. Color: chestnut brown; head before constriction, rostrum, and elytra beyond declivity until apex dark brown; glossy, glabrous, vitreous . Rostrum ( Fig. 6 ): moderately long, broadly curved dorsally after point of antennal insertion (basal half), anterior half flat, nearly parallel-sided, with dense elliptical punctures throughout, punctures becoming smaller at apex; punctures separated by 1– 3x diameter of puncture, with short median elliptical sulcus at point of antennal insertion. Scrobe: well-defined, wide, deep, triangular, covering basal 2/3 of rostrum, extending to just before anterior margin of eye; point of antennal insertion at basal 1/3 of rostrum; dorsal margin extending to same level as dorsal margin of eye, then extending to ventral margin of eye proximally; ventral margin black, extending below ventral margin of eye. Antennae: dark brown, glossy, long, stout; scape clavate, robust, extending slightly beyond posterior margin of eye, curved upwards at distal 1/4, nearly equal to length of funicle and club combined, with sparse punctures; funicle compact, with 7 subclavate articles and fine, sparse, suberect setae; first article longer and wider than second one; club composed of 3 articles, pale yellowish-brown, ovate, compressed (dorso-ventrally flattened), with short, appressed, sub-erect setae. Head: oval, constricted just behind eyes, constriction pronounced laterally, shallow dorsally, not touching eyes; oblong to subcircular punctures before constriction, becoming larger and more dense after constriction; vertex convex; frons wider than rostrum base, with oblong median fovea; eyes reddish-brown, with some black maculae; broadly convex, subcircular, with smooth, fine, convex facets; widely separated dorsally, located laterally before base of rostrum. Pronotum: longer than wide, constricted anteriorly, forming broad collar with continuous black stripe; broadly curved dorsally, with sparse, shallow, fine circular punctures throughout, punctures separated by approximately 2– 5x puncture diameter; basal margin sub-linear, lateral margins broadly convex. Scutellum: circular, dark brown, glossy, slightly sunken below level of elytral disc, convex. Elytra: shiny, disc convex, uniform, and elongate; lateral sides parallel until declivity, moderately tapered to apex beyond declivity, apical margin rounded, base sublinear; striae with shallow circular punctures, punctures separated by approximately 1x puncture diameter or less, stria 6 not reaching base, stria 1 deeper than others, particularly at base; intervals slightly convex, wider than striae, sub-equal in width, with single row of fine punctures; intervals 1 and 2 not dilated beyond declivity, intervals 4, 5, and 6 merging at declivity, intervals 3 and 9 connecting slightly beyond declivity; humeri truncate, umbonate.

Abdominal terga:male ( Fig. 36 ) with entire median sclerites on tergites 4–6, those on tergite 3 partial; male with more strongly sclerotized bands along anterior margins of median sclerites on tergites 4–6, bands becoming increasingly thicker caudally; tergite 7 bearing two longitudinal rows of stridulatory plectra.

Venter: with sparse, shallow, circular punctures throughout with minute appressed setae, punctures separated by approximately 5x puncture diameter; prosternum punctures more shallow and sparse, procoxae separated by slightly less than one diameter of coxa; mesoventrite with mesocoxae separated by slightly more than diameter of coxa, posterior margin curved, suture black; metaventrite long, posterior margin bi-sinuate; median longitudinal sulcus (discrimen) at posterior 1/2; ventrites: with sparse, circular punctures; ventrites I and II wide, separated by shallow furrow which is distinct laterally, obscure ventrally; punctures on I–II separated by distance approximately 2– 3x puncture diameter, with minute suberect setae; III and IV sub-equal in width, with row of punctures along inner margin; V with shallow depression at apex, rounded at apical margin, with fine sparse punctures. Legs: femur longer than tibia, rugose, robust at distal two-thirds, slightly laterally compressed (mid- and hind femora laterally compressed), sparsely punctate, black near joints; tibia moderately robust, with elliptical, sparse punctures, uncus at outer apical angle approximately same length as fifth tarsomere; small mucro on inner apical angle; front tibia with setal comb along distal margin before uncus; small black projection approximately 0.5x length of uncus along inner subapical margin and more proximal than mucro (adjacent to the distal comb of setae and above the tarsal groove); tarsus with tarsomeres slightly compact, distal margins bearing pale, suberect setae; tarsomere 1 longer than wide, 3 nearly entire, slightly notched distally; tarsomere 5 long, slightly tapering distally, smooth, glossy, broadly curved, cylindrical; pretarsal ungues (claws) simple.

Male terminalia and genitalia ( Figs. 29–35 ): Spiculum gastrale of sternite IX broadly curved, with narrow, flattened apex, base narrow, broadly bifid. Eighth sternite divided, large, quadrate, each sclerite bearing ca. 5 setae at apico-lateral margins; apical membranous area with a dense covering of acute triangular spines. Tegmen complete, narrow; dorsal parameroid lobes absent; manubrium short, less than 0.5 x length of tegmen, with central longitudinal rib bearing 2 elongate spines at posterior margin. Penis with median struts (temones) ca. 2.5 x length of median lobe; apical margin of median lobe bearing many setae; endophallus (internal sac) bearing several small, elongate paired sclerotizations near apex.

Female terminalia and genitalia ( Figs. 37–38 ): Gonocoxites of typical form; coxites oblong, incomplete baso-laterally at attachment to oviduct (basal concave areas of coxites); styli elongate, narrow, each stylus bearing ca. 5 apical setae. Spermatheca falciform, with globular base, apex strongly curved and narrowing. Eighth sternite unknown.

Etymology. The specific epithet is derived from the Latin word " vitreous ", referring to the “glass-like” elytra of the species.

Host plant: Unknown.

Distribution: Yunnan Province, southern China.

Sexual dimorphism: The male rostrum is longer than that of the female and widens at its apex, whereas the female rostrum is parallel-sided.

Ecological notes on other species: Two species of Coptus have been collected from higher altitudes: C. latiusculus Champion was found on Cascade Estate at 800–1000 feet in Mahé, Seychelles, and C. anamalainus Marshall was found on Anamalai hills at 2400 feet in south India.

Figures

FIGURES 1 – 6. 1 – 3, Coptus brevirostris. 1, dorsal view; 2, lateral view; 3, antero – dorsal view of head and pronotum. 4 – 6, Coptus vitreous. 4, dorsal view; 5, lateral view; 6, antero-dorsal view of head and pronotum.

FIGURES 29 – 32. Coptus vitreous, male terminalia. 29, aedeagus, dorsal view (photomicrograph); 30, ditto; 31, aedeagus, lateral view (photomicrograph); 32, ditto.

FIGURES 33 – 38. Coptus vitreous. 33 – 35, male terminalia. 33, 8 th and 9 th sternites, dorsal view (photomicrograph); 34, ditto; 35, tegmen, dorsal view. 36, tergum: SS = spiracular sclerites, MS = median sclerites. 37 – 38, female terminalia. 37, coxites and styli; 38, spermatheca.