Pelenomus curvatus Yang & Huang

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 : 413-419

Pelenomus curvatus Yang & Huang , sp. nov.

( Figs.17–20 , 37–40, 73–81, 86–88)

Description. Male. LB: 2.14–2.59 mm (mean, 2.31 mm); LR: 0.42–0.50 mm (0.47) mm; WP: 0.78–0.81 mm (0.80 mm); LP: 0.48–0.56 mm (0.53 mm); WE: 1.21–1.37 mm (1.29 mm); LE: 1.34–1.56 mm (1.43 mm). N = 4 for all measurements.

Body black; elytra shining; eyes and antennae reddish-brown; legs dark brown. Habitus as shown in Figs. 17 and 18 .

Vestiture fine. Head (Figs. 37–38) with moderately sparse dark brown linear scales on disc, and sparse white oval scales behind eyes; rostrum with dense brown hairlike scales. Pronotum ( Fig. 17 ) with brown linear scales, plus white oval scales on basal part and lateral sides. Elytra ( Fig. 17 ) with scutellar spot formed of white oval scales; intervals bearing 3–4 rows of dark brown linear scales; striae bearing a fine hairlike scale in each puncture. Underside ( Figs. 18–19 ) covered with white oval scales. Legs ( Fig. 6 ) moderately clothed with dense white linear scales. Pygidium ( Fig. 20 ) with dense dark brown hairlike scales.

Rostrum robust, 0.85–0.96 times longer than the pronotum. In dorsal view (Fig. 37), rostrum straight and almost parallel-sided, not widened at base and beyond the antennal insertion weakly widened towards apex; dorsal surface without median carina nor sulcus, with shallow elongate medium-sized punctures on each side, forming two to three lines of ill-defined wrinkles; apical part of rostrum smooth, shining, with sparse fine punctures. In lateral view (Fig. 38) rostrum slightly curved; dorsal outline slightly more strongly curved than the ventral one. Frons distinctly narrower than the base of rostrum, subparallel, not widened basally; frons and vertex uniformly covered with shallow medium-sized punctures. Antennae with scape 0.78 times as long as the funicle, length ratio of funicular segments I: II: III: IV: V: VI = 1.89: 1.71: 1.03: 1.26: 1.43: 1.00 and width ratio = 2.29: 1.00: 1.43: 1.62: 1.86: 2.10.

Pronotum ( Fig. 17 ) 1.44–1.65 times wider than long, 0.35–0.42 times as long as and 0.58–0.66 times as wide as elytra, bearing a pair of small tubercles at the middle of the lateral sides. Dorsum deeply punctured, and with shallow median suture; basal margin not serrate; apical margin moderately raised. Sides subparallel in basal half, weakly converging toward the subapical constriction. Scutellum subovate.

Elytra ( Fig. 17 ) 1.02–1.19 times longer than wide, 2.39–3.13 times longer and 1.51–1.74 times wider than pronotum, widest at humeri, subparallel in basal 3/4, then moderately convergent toward subapical calli. Intervals strongly convex, as wide as striae, bearing 3–4 rows of sparse acute granules; striae moderately marked, relatively deep, with distinct punctures.

Legs ( Fig. 18 ) slender, procoxae separated by about the 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 normal, about the same size of front femora; middle and hind tibiae with fine mucro; tarsi moderate in length; claws appendiculate, inner branches separate.

Prosternum simple, without prosternal canal. Venter ( Fig. 19 ) coarsely and moderately densely punctured; ventrites I and II concave on the disc, ventrites V with a small median concavity; length ratio of ventrites I: II: III: IV: V = 4.47: 3.20: 1.11: 1.00: 1.35 and width ratio =1.56: 1.32: 1.10: 1.00: 1.84.

Pygidium ( Fig. 20 ) 1.18 times wider than long. Sternite IX ( Fig. 77 ) with spiculum gastrale relatively slender, slightly longer than aedeagal body or its apodeme, bent leftward. Tegmen ( Fig. 76 ) with the apodeme short and robust, nearly half as long as diameter of tegminal ring; sides of apodeme fully separated in basal half. Aedeagal body ( Figs. 73–75 ) broad, strongly curved downward at apex; sides weakly narrowed from base to middle, slightly broadened to apical third, then gradually convergent apically; apical projection rounded at apex. Endophallus ( Fig. 73 ) with sparse longitudinal dentiform spicules near the base, and a dentiform spiculate field in the middle.

Female. LB: 2.21–2.60 mm (mean, 2.48 mm); LR: 0.49–0.53 mm (0.52 mm); WP: 0.80–0.84 mm (0.83 mm); LP: 0.51–0.62 mm (0.58 mm); WE: 1.26–1.45 mm (1.37 mm); LE: 1.37–1.63 mm (1.52 mm). N = 4 for all measurements.

FIGURES 21–32. Heads of Pelenomus spp. (21–24) P. waltoni . (25–28) P. canaliculatus . (29–32) P. quadricorniger . (21–22, 25–26, 29–30) Male. (23–24, 27–28, 31–32) Female. (21, 23, 25, 27, 29, 31) Dorsal view. (22, 24, 26, 28, 30, 32) Lateral view. Scale bars: 0.50 mm.

FIGURES 33–40. Heads of Pelenomus spp. (33–36) P. ro e l o f s i. (37–40) P. c u r v a t u s. (33–34, 37–38) Male. (35–36, 39–40) Female. (33, 35, 37, 39) Dorsal view. (34, 36, 38, 40) Lateral view. Scale bars: 0.50 mm.

Rostrum (Figs. 39–40) shorter than pronotum, 0.86–0.96 times longer than pronotum. Pronotum 1.37–1.42 times wider than long. Elytra 1.04–1.18 times longer than wide. Tibiae not mucronate. Ventrite I and II moderately inflated and punctured; ventrite V slightly inflated, without concavity.

Pygidium 1.57 times wider than long. Sternite VIII ( Fig. 79 ) with several minute setae near the apex; arms wide, nearly 0.7 times as long as apodemes, nearly half as long as the coxite and stylus combined, with inner margins strongly arcuate, with outer margins broadly arcuate; apodemes weakly broadened at the base. Coxites ( Fig. 80 ) robust, 1.5 times wider than long, nearly four times longer than styli; styli apicolaterally inserted, moderate in length, nearly three times longer than wide. Spermatheca ( Fig. 81 ) with cornu robust, strongly curved; collum evenly and moderately convex; ramus less-marked; insertions of the duct and gland close to each other.

Distribution. China (Yunnan; Fig. 88 ).

Type Specimens. HOLOTYPE: male (ZAFU), [ China: Yunnan] / Tengchong / Mangbang / Dahaoping / 2417 m / N 24°55.592ʹ E 98°45.148ʹ / 22-V-2009 / J. Huang / on Polygonum thunbergii Sieb. et Zucc. / CU00001. PARATYPES: 2 males and 3 females, same data as holotype [CU00002–00006] (ZAFU); 1 female, Tengchong, Mangbang, Dahaoping, Taipingpu, 2259 m, N 24°57.569ʹ E 98°44.291ʹ, 22-V-2009, J. Huang [CU00007] (ZAFU); 1 male, Tengchong, Beihai, Shuanghai vill, 1760 m, 29-V-2006, C. Yin, IOZ(E) 1803571 (IZCAS).

Etymology. The species is named after its apically strongly curved aedeagal body, from the Latin adjective curvatus , meaning curved.

Biological note. Adults of this species were collected from Polygonum thunbergii Sieb. et Zucc. in the semiaquatic rainforest habitat in Tengchong, Yunnan ( Figs. 86–87 ).

Remarks. The new species is close to P. ro e lo fs i as shown by the black body, middle and hind tibiae mucronate and male ventrite V with small median concavity. Pelenomus curvatus differs from P. ro e l o f s i by the shining elytra, elytral intervals strongly convex and as wide as striae, and frons distinctly narrower than the base of rostrum, versus the quite opaque elytra, intervals moderately convex and much wider than striae, frons clearly narrower than the base of rostrum of P. ro e l o f s i. In addition, the strongly curved aedeagal body is unique among the Chinese Pelenomus .

Figures

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

FIGURES 17 – 20. Pelenomus curvatus sp. nov., male. (17) Dorsal habitus. (18) Lateral Habitus. (19) Venter. (20). Pygidium. Scale bar: 0.50 mm for 17 – 19; 0.25 mm for 20.

FIGURES 5 – 8. Pelenomus canaliculatus, male. (5) Dorsal habitus. (6) Lateral Habitus. (7) Venter. (8). Pygidium. Scale bar: 0.50 mm for 5 – 7; 0.25 mm for 8.

FIGURES 73 – 81. Male and female genitalia of Pelenomus curvatus from Yunnan, China. (73 – 77) Male. (73) Aedeagus, dorsal view. (74) Apex of the aedeagal body, dorsal view. (75) Aedeagus, lateral view. (76) Tegmen. (77) Sternites IX. (78 – 81) Female. (78) Terminalia. (79) Sternite VIII. (80) Coxite and stylus. (81) Spermatheca. Scale bar: 0.20 mm for 73 – 79, 0.10 mm for 80 – 81.

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.