Pelenomus roelofsi (Hustache, 1916)

Yang, Lujing, Huang, Junhao, Zhang, Runzhi & Wu, Hong, 2013, A review of the genus Pelenomus Thomson (Coleoptera: Curculionidae: Ceutorhynchinae) from China, Zootaxa 3652 (4), pp. 401-423 : 409-413

Pelenomus roelofsi (Hustache, 1916)

( Figs. 13–16 , 33–36, 65–72, 84–85, 88)

Description. Male. LB: 2.35–2.55 mm (mean, 2.47 mm); LR: 0.48–0.53 mm (0.51 mm); WP: 0.89–0.92 mm (0.90 mm); LP: 0.62–0.66 mm (0.64 mm); WE: 1.44–1.60 mm (1.52 mm); LE: 1.58–1.80 mm (1.66 mm). N = 3 for all measurements. Body black; head, pronotum and elytra black; eyes yellowish-brown; antennae and legs reddishbrown. Habitus as shown in Figs. 13 and 14 .

Vestiture fine. Head (Figs. 33–34) moderately covered with sparse brown hairlike scales on disc and sparse white oval scales behind eyes; rostrum with dense brown hairlike scales. Pronotum ( Fig. 13 ) with brown linear scales in general, and white oval scales in basal part and lateral sides. Elytra ( Fig. 13 ) with scutellar spot formed of white oval scales; intervals bearing 3–4 rows of dark brown linear scales; striae bearing fine hairlike scale in each puncture. Underside of body ( Figs. 14–15 ) covered with oval white scales. Legs ( Fig. 14 ) moderately clothed with dense white linear scales. Pygidium ( Fig. 16 ) with dense dark brown hairlike scales.

Rostrum robust, 0.73–0.83 times longer than the pronotum. In dorsal view (Fig. 33) rostrum slightly widened basally, almost parallel-sided in basal half, and broadest at apex; dorsal surface without median carina nor sulcus, with shallow elongate medium-sized punctures on each side, forming two-three lines of ill-defined wrinkles; apical part of rostrum smooth, shining, with sparse fine punctures. In lateral view (Fig. 34) rostrum slightly curved; dorsal outline curved as the ventral one. Frons clearly narrower than the base of rostrum, then gradually widened basally; frons and vertex uniformly covered with shallow medium-sized punctures. Antennae inserted at the apical part of rostrum, scape 0.78 times as long as the funicle, length ratio of funicular segments I: II: III: IV: V: VI = 3.33: 2.61: 1.88: 1.06: 1.15: 1.00 and width ratio = 1.87: 1.04: 1.00: 1.13: 1.35: 1.43.

Pronotum ( Fig. 13 ) 1.40–1.44 times wider than long, 0.34–0.41 times as long as and 0.55–0.63 times as wide as elytra, bearing a pair of tubercles at the middle of lateral sides. Dorsum deeply punctured, and with shallow median suture; basal margin serrate; apical margin moderately raised. Sides moderately rounded, widest at middle, weakly converging toward the subapical constriction. Scutellum subovate.

Elytra ( Fig. 13 ) heart shaped, 1.05–1.10 times longer than wide, 2.41–2.93 times longer and 1.57–1.81 times wider than pronotum; widest at humeri, subparallel in basal 2/3, then moderately convergent toward subapical calli. Intervals moderately convex, nearly two times wider than striae, all of almost the same width and height, each with 3–4 rows of large and acute squamate granules; striae moderately marked, with distinct punctures.

Legs ( Fig. 14 ) slender, procoxae separated by about the same width of basal rostrum; middle coxae separated by a distance equal to the apical width of rostrum. Femora clavate, without tooth; middle and hind femora more inflated than front femora; middle and hind tibiae with sharp mucro; tarsi moderate in length; claws appendiculate, inner branches separate.

Prosternum simple, without prosternal canal. Venter ( Fig. 15 ) coarsely and moderately densely punctured; ventrite I shallowly concave on disc; ventrite V with a small deep median concavity; length ratio of ventrites I: II: III: IV: V = 4.15: 2.44: 1.00: 1.05: 1.65 and width ratio =1.82: 1.49: 1.31: 1.20: 1.00.

Pygidium ( Fig. 16 ) 1.32 times wider than long, densely punctured. Sternite IX ( Fig. 69 ) with spiculum gastrale relatively robust, widest in the median part, longer than the aedeagal body or its apodeme, bent leftward. Tegmen ( Fig. 68 ) with apodeme raletively slender, nearly half as long as diameter of tegminal ring, subparallel along entire length, rounded at base. Aedeagal body ( Figs. 65–67 ) broad, relatively thin in profile, moderately curved downward in the basal fourth, then slightly bent leftward at apex; sides gradually broadened from the base to middle, slightly narrowed to the basal 2/3, and broadened in the apical fifth, then strongly convergent apically; apical projection sharp at apex. Endophallus ( Fig. 65 ) with numerous longitudinal dentiform spicules, and dense rounded spicules near the base.

Female. LB: 2.29–2.69 mm (mean, 2.52 mm); LR: 0.47–0.57 mm (0.52 mm); WP: 0.82–1.02 mm (0.92 mm); LP: 0.57–0.70 mm (0.66 mm); WE: 1.42–1.68 mm (1.58 mm); LE: 1.44–1.76 mm (1.65 mm). N = 3 for all measurements.

Rostrum (Figs. 35–36) shorter than pronotum, 0.75–0.83 times longer than pronotum. Pronotum 1.32–1.47 times wider than long. Elytra 1.01–1.07 times longer than wide. Tibiae not mucronate. Ventrites I and II moderately inflated and punctured; ventrite V slightly inflated without concavity.

Pygidium 1.37 times wider than long. Sternite VIII ( Fig. 70 ) with several minute setae near the apex; arms very wide, nearly 0.6 times as long as apodemes, nearly as long as the coxite and stylus combined, with inner margins broadly and shallowly arcuate, with outer margins broadly arcuate; apodemes strongly broadened at base. Coxites ( Fig. 71 ) robust, nearly six times longer than styli; styli apicolaterally inserted, moderate in length, nearly two times longer than wide. Spermatheca ( Fig. 72 ) with cornu robust, strongly curved; collum evenly and moderately convex; ramus weakly marked; insertions of the duct and gland close to each other. Otherwise practically as in male.

Distribution. China (Liaoning, Zhejiang, Fujian, Jiangxi, Hunan, Guangxi, Guizhou— new record; Fig. 88 ), Northeast Asia (Colonnelli, 2004).

Specimens examined. LIAONING. 1 female, Xinjin, Mt. Huarshan, IOZ(E) 895194 (IZCAS); 1 male, Yichun, Wuying, Fenglin 14-16, 20-VII-2008, J. Huang (ZAFU). ZHEJIANG. 2 males and 1 female, Pujiang, Yantou, Sanbushi, IOZ(E) 985831, 1027060, 1027112 (IZCAS); 2 males and 3 females, Lin’an, Mt. Qingliangfeng, 7-VIII-2008, J. Huang (ZAFU); 1 male, 150 m, Chun’an, Fuxi, 14-VII-2008 (ZAFU). FUJIAN. Jiangle, Mt. Longqishan: 1 female, 500 m, 13-VIII-1991, X. Zhang, IOZ(E) 895301 (IZCAS); 1 male and 1 female, 350 m, 30- V-1991, H. Li, IOZ(E) 895305–895306 (IZCAS). 4 males and 2 females, IV. 2005 (NIAES). JIANGXI. 1 female, Mt. Jiulianshan, Huangniushi, 27-IX-1979, Y. Chen, IOZ(E) 895637 (IZCAS). 19 males and 8 females, Yingtan, Mt. Longhushan, VIII. 2003, Li et al (NIAES). 7 males and 8 females, Zixi, Yangjialing, VIII. 2003, Wen et al (NIAES). HUNAN. 1 male, Pingjiang, Mt. Mupushan, 1600 m, bordering on Jiangxi, 12-VIII-2003, Li et al (NIAES). 1 male and 3 females, Mt. Hengshan, 1500 m, VIII. 2003, Li et al (NIAES). 1 female, Shimen, Mt. Hupingshan, 2000 m, 30-VI-1987, IOZ(E) 895670 (IZCAS). GUANGXI. 1 female, Jinxiu, Huawangshanzhuang, 20-V-1999, M. Gao, IOZ(E) 895097 (IZCAS). GUIZHOU. 1 male and 1 female, Leishan, Mt. Leigongshan, Xiaodanjiang, 31-V-2005, J. Huang, IOZ(E) 895674, 895674 (IZCAS).

Biological notes. On Polygonum (Colonnelli, 2004) . In August, 2012, a dozen adults were collected in Yujiaping, Mt. Longqishan, Fujian by sweeping in a moist bamboo forest ( Figs. 84–85 ), where the dominant buckwheat weeds were mainly Polygonum muricatum Meisn. , and peripherally Polygonum caespitosum Bl. and Antenoron filiforme (Thunb.) Rob. et Vaut. In addition, some species of the ceutorhynchine genera Rhinoncus Schoenherr, 1825 and Homorosoma Frivaldszky, 1894 were also found in the same site.

Remarks. The species is a new record to China, where it is widely distributed in the east of the country. It is very close to P. quadricorniger in general appearance. For their differential diagnosis, see under the former species.

Figures

FIGURE 88. Geographic distribution of the genus Pelenomus in China.

FIGURES 13 – 16. Pelenomus roelofsi, male. (13) Dorsal habitus. (14) Lateral Habitus. (15) Venter. (16). Pygidium. Scale bar: 0.50 mm for 13 – 15; 0.25 mm for 16.

FIGURES 65 – 72. Male and female genitalia of Pelenomus roelofsi from Zhejiang, China. (65 – 69) Male. (65) Aedeagus, dorsal view. (66) Apex of the aedeagal body, dorsal view. (67) Aedeagus, lateral view. (68) Tegmen. (69) Sternites IX. (70 – 72) Female. (70) Sternite VIII. (71) Coxite and stylus. (72) Spermatheca. Scale bar: 0.20 mm for 65 – 70, 0.10 mm for 71 – 72.

FIGURES 82 – 87. (82 – 83) Pelenomus quadricorniger. (82) Adult food plant, Polygonum hastato-sagittatum Mak. (83) Habitat in Shipaichang, Mt. Longqishan, Jiangle, Fujian, China. (84 – 85) Pelenomus roelofsi. (84) Adult food plant, Polygonum muricatum Meisn. (85) Habitat in Yujiaping, Mt. Longqishan, Jiangle, Fujian, China. (86 – 87) Pelenomus curvatus sp. nov. (86) Adult food plant, Polygonum thunbergii Sieb. et Zucc. (87) Habitat in Dahaoping, Mangbang, Tengchong, Yunnan, China.