Enaptorhinus shansiensis Han & Zhang, 2007

Han, Kyungduk, Zhang, Runzhi & Pelsue, Frank W., Jr., 2007, Keys To The Species Of The Genus Enaptorhinus Waterhouse (Coleoptera: Curculionidae: Entiminae: Tanymecini) With Description Of A New Species From China, The Coleopterists Bulletin 61 (1), pp. 127-134 : 130-133

Enaptorhinus shansiensis Han & Zhang , new species

( Figs. 1–9 )

Holotype. China. Wutaishan : male. [Wutaishan (38.9uN, 113.3uE) 1,800 m, Shanxi Province, China. 1964.VI.10, collected by Tiesheng Li, (Institute of Zoology, the Chinese Academy of Sciences, Beijing)]

Paratypes. China. Wutaishan : 17 males and 5 females. Same data as the holotype, except 1964.VI.10–14.

Diagnosis. Dorsal surface of the rostrum very tumid compared to frons. Dorsal surface of elytra slightly convex, without keel on 5th interval. Antennal scape reaching middle eye. Antennomere 1 of funicle much longer than 2 (1.7: 1). Elytra densely covered with scales on anterior part of 3rd and 5th intervals and on middle portion of 1st interval. Elytral intervals without peaked granules and with broad, leaf-like, sub-erect setae. Anterior margin of elytral punctures with short, broad, leaf-like seta. Base of mandibular scar more developed than in the other members of Enaptorhinus . Body shape (especially elytral shape) of male similar to that of female ( Fig. 2 ).

Description. Male. BL 6.7 mm; BW 2.5 mm; EL 4.4 mm; EH 1.6 mm; PNL 1.7 mm; PNW 1.8 mm; RL 1.0 mm; RWA 0.8 mm; RWB 0.8 ( Fig. 1 ). Body: color reddish brown, covered with pearly circular or oval scales; ventral surface densely covered with oval scales. Head ( Figs. 3A and 4A ) with mandible covered with many hair-like setae, basal part of mandibular scar projected strongly; epistoma small, V-shape, posterior parts slightly depressed and sparsely covered with small, circular scales; rostrum longer than wide, base of the rostrum as wide as apex; dorsal surface of rostrum strongly tumid, smooth, without punctures or wrinkles, sparsely covered with small, circular scales; pterygium of rostrum undeveloped so that anterior inside of antennal scrobe visible in dorsal view; antennal scape reaching middle of eye; antennal funicle ( Fig. 5A ) as long as scape, antennomeres short, stout, funicular antennomere 1 longer than 2; antennal club cone-shaped; eye circular to elliptical, slightly tumid. Pronotum slightly broader than long; with a narrow, longitudinal groove in middle; dorsal surface with dull granules as wrinkles, sparsely covered with scales; vibrissae slightly developed; basal margin weakly carinate. Elytra ( Figs. 6A and 7A ) elongate oval, sides parallel, dorsal surface of elytra sparsely covered with small or large oval or circular scales, densely covered on some parts (on the central parts of 1st interval, on intervals 3 to 5 of declivity, on intervals 7 to 10); surface of each interval smooth, without peaked granules, covered with narrow leaf-like, sub-erect setae, setae little longer than a scale on the elytral interval, setae arranged in a row from base to middle and arranged in 1–2 rows from middle to declivity area; each anterior part of puncture with a small, short leaf-like seta shorter than scale diameter. Legs: femora and tibiae sparsely covered with small circular and oval scales, or densely on outer surface of femora; inner surface of fore tibia with long bristles and small teeth; tarsomeres without scales densely covered with long, erect setae. Abdomen ( Fig. 8 ) with ventral surface densely covered with oval scales; anterior margin of 2nd sternite strongly bisinuate; 2nd, 3rd and 4th sternites tumid, posterior margin straight; mid-longitudinal length of 2nd sternite as long as 3rd+4th, 5th a little shorter than 3rd+4th. Genitalia: apophysis of tegmen long ( Fig. 9A ).

Female. Body habitus, head and rostrum, and abdominal sternites as illustrated ( Figs. 2C–D, 3B and 8B . Spermatheca simple, slim ( Fig. 9B ).

Size variation: male. BL 5.4–7.2 mm; BW 1.9–2.5 mm; EL 3.6–4.8 mm; EH 1.3–1.8 mm; PNL 1.3–1.7 mm; PNW 1.4–1.8 mm; RL 0.9–1.0 mm; RWA 0.6– 0.8 mm; RWB 0.6–0.8; female. BL 6.0– 6.7 mm; BW 2.4–2.7 mm; EL 4.2–4.8 mm; EH 1.4–1.7 mm; PNL 1.3–1.6 mm; PNW 1.5–1.8 mm; RL 0.88–0.92 mm; RWA 0.7–0.77 mm; RWB 0.7–0.77 mm.

Associated plants. Species of the family Cupressaceae .

Etymology. Named in reference to its geographical distribution ‘‘ shansi -’’ (5 Shanxi) Province.

Discussion. Enaptorhinus shansiensis is very similar to E. argentellus based on the following characters: tumid dorsal surface present on rostrum, peaked granules absent on the elytral intervals, and narrow leaf-like setae present on elytral intervals ( Figs. 4C ; 6C ; 7C ). However, the dorsal surface of the elytra in E. argentellus is flat ( Fig. 7C ), whereas the elytral dorsal surface in E. shansiensis is more convex ( Fig. 7A ). The other members of Enaptorhinus (except E. fallax and E. dispar ) have granules and fine, hair-like setae on the elytral intervals similar to E. sinensis ( Fig. 6B ).

The body shape (especially elytral shape) of male E. shansiensis is similar to that of the female ( Fig. 2 ), while the other members of the genus Enaptorhinus have different types of body shapes between male and female (male slimmer than female), but the sexes of E. shansiensis can be distinguished by the following characteristics: mid-longitudinal length of 2nd sternite as long as 3rd+4th, 5th a little shorter than 3rd+4th in males; 2nd sternite a little longer than 3rd+4th, 5th as long as 3rd+4th in females ( Fig. 8 ).

Enaptorhinus shansiensis has been collected only from northeast China (Shanxi) but E. argentellus is distributed widely in China from Beijing to Hainan. Most specimens of E. argentellus have been collected from Zhejiang and Jiangxi on the border between the Eastern Palaearctic Region and Oriental Region (South East Asia). The other members of Enaptorhinus (except E. fallax and E. dispar ) are distributed only in northeastern China and the Korean peninsula, excluding Far East Russia and Japan ( Han 2002; Han and Zhang 2005).

Figures

Fig. 1. Body measurements. Enaptorhinus shansiensis n. sp. male. BL-body length; BWbody width; ED-elytral declivity; EH-elytral height; EL-elytral length; PNL-pronotal length; PNW-pronotal width; RL-rostral length; RWA-rostral width at apex; RWB-rostral width at base. A) dorsal view of body; B) dorsal view of rostrum; C) lateral view of elytron.

Fig. 2–3. Enaptorhinus shansiensis n. sp. and E. sinensis. 2) Habitus of E. shansiensis n. sp. a) dorsal view of male; b) lateral view of male; c) dorsal view of female; d) lateral view of female. 3) Head and rostrum of E. shansiensis n. sp. a) male; b) female; and E. sinensis c) male; d) female).

Figs. 4–5. Enaptorhinus shansiensis n. sp. and E. sinensis. 4) Lateral view of head. A) E. shansiensis n. sp.; B) E. sinensis; C) E. argentellus. 5) Antenna. A) E. shansiensis n. sp.; B) E. sinensis.

Fig. 6. Dorsal surface of elytron. A) E. shansiensis n. sp.; B) E. sinensis; C) E. argentellus.

Fig. 7–9. Enaptorhinus shansiensis n. sp. and E. sinensis. 7) Cross section of elytra: A) E. shansiensis n. sp.; B) E. sinensis; C) E. argentellus. 8) Abdominal sternites of E. shansiensis n. sp. A) male; B) female. 9) Genitalia of E. shansiensis n. sp. A) male, median lobe; B) female, spermatheca.