The new genus Pheude (Coleoptera, Curculionidae, Cossoninae) with description of a new species from mainland China

Abstract A new weevil, Pheude punctatus gen. et sp. n., of the tribe Dryotribini in Cossoninae, is described from Guangdong Province, South China. It differs from the related genera Dryotribus Horn and Microtribodes Morimoto in having antennae with seven articles and a distinct scutellum, and from Ochronanus Pascoe and Stenomimus Wollaston in having long antennae, a rostrum with a medio-longitudinal furrow beginning at the posterior margin of the eyes and extending approximately midway on the rostrum, and a moderately elevated, medio-longitudinal carina extending the full length of the pronotum. Other diagnostic characters and illustrations are provided. A key to the genera of Dryotribini known from China is given.


Introduction
Cossoninae are small to medium-sized, primarily wood-associated weevils with a worldwide distribution. They are represented in China by six tribes, 32 genera, and 72 species (YMO unpublished data based on collection at Institute of Zoology, Chinese Academy of Sciences, Beijing). All native genera are widely distributed in China except for the monotypic Muschanella Folwaczny, 1964(Folwaczny 1964 and Microtribodes Morimoto, 1973 (Morimoto 1973) which are known only from Zhejiang Province (East China) and Taiwan, respectively. In this study, we describe a new genus and species of Dryotribini LeConte, 1876 from Guangdong Province (South China). Species in this tribe are coarsely sculptured, have an elongate, apically subcylindrical rostrum, funicle with five, six or seven articles, head small with slight post-ocular constriction, dorso-lateral eyes, visible or obscure scutellum, and slender tibiae (LeConte 1876;Voss 1955;Konishi 1962;Decelle and Voss 1972;Folwaczny 1973); the new genus is exceptional in that the elytra narrow slightly from base to apex, whereas they do not narrow apically in the other genera. Dryotribini contain 49 genera in the Palearctic, Neotropical, Afrotropical, Oriental, Neoguinean and Neozelandic Regions (Alonso-Zarazaga and Lyal 1999, regional nomenclature from Cox 2001). In China, Dryotribini are represented by Dryotribus Horn, 1873, Microtribodes, Ochronanus Pascoe, 1885 and Stenomimus Wollaston, 1873 (Csiki 1936;Zhang 1992;Alonso-Zarazaga and Lyal 1999;Kojima and Morimoto 2004).

Materials and methods
The type specimens are deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing, China. Observations were made with a Zeiss Semi SV 11 stereomicroscope. Habitus photographs were taken by Micropublisher 5.0 RTV digital camera model: MP5.0-RTV-CLR-10A-color 10 BIT, attached to a Zeiss Stereomicroscope Discovery V12. SEM images were captured using a LEO 1550 FESEM.
Measurements were taken as follows: antennal club width measured at the widest part of the club; body length measured in lateral view from the apex of the elytra to the anterior end of the rostrum; elytral length measured in lateral view starting from the base to the apex; pronotal length measured along the median line; rostral length measured in lateral view from the anterior edge of the eyes to the apex. Funicular articles are enumerated beginning with the pedicel and including all articles before the club. On the elytra, intervals and striae are numbered beginning from the suture and extending laterally. Hind wing terminology follows Zherikhin and Gratshev (1995 Diagnosis. Rostrum nearly parallel-sided, rostrum without any keel ventrally, longer than wide (more than 2 × width), with longitudinal furrow dorsally; antenna inserted at basal one-third of rostrum; scape extending beyond hind margin of eye, funicle with seven articles; pronotum longer than wide, base bisinuate, with longitudinal median crest from base to apex; scutellum visible; apical margin of elytra expanded and lower than level of venter, elytral apical margin gently rounded and flattened; third tarsomere entire.
Proventriculus as in Figure 18. Rostrum longer than broad, punctures with minute suberect setae, with large, deep, longitudinal furrow beginning behind eyes and extending to point of antennal insertion, forming slight cleft in rostrum; point of antennal insertion at basal 1/3 of rostrum; scrobe well-defined, deep, dorsal margin directed towards middle of eye but not touching eye, subsequently extending ventrally below eye.
Antennae long, stout; scape: clavate, extending slightly beyond hind margin of eyes; funicle with seven articles; article one (pedicel) longer than others, as well as longer than own width; article two small, shorter than others and shorter than own width; club with three articles, appearing to have four with apical constriction, shorter than funicle. Head small, strongly constricted behind eyes; frons as broad as base of rostrum, with long longitudinal furrow extending midway on rostrum. Eyes oval, strongly convex.
Pronotum longer than wide, constricted behind apex. Scutellum visible, deeply sunken, subcircular, finely punctured. Elytra wider than pronotum, transversely concave immediately after antero-dorsal margin; basal margin forming transverse keel from sutural interval to humeri. Humeri umbonate, truncate. Intervals elevated from base to apex; striae wider than intervals, with deep circular punctures, distance between punctures ca. 1.5-2.0 × puncture diameter; apex of elytra (from declivity to apex) expanded laterally and extending slightly below level of abdomen; apices gently rounded and slightly upturned.
Legs. Femur strong, longer than tibia, entirely punctured; tibiae parallel-sided; protibia with distal comb of setae along inner margin; tarsus with five articles, articles one and two equal, three entire, feebly longer and wider than one and two combined; five slightly curved, glossy.
Etymology. The name of the new genus honors Pierre Heude (1836-1902), a French Jesuit and zoologist who came to China in 1868. Heude was a cofounder of the first natural history museum in China, and the oldest insect specimens housed in the CAS Institute of Zoology are from this museum, often collected by Octavie Piel. The gender is masculine.  Integument. Body densely, deeply punctured throughout (Fig. 24); Color brown to dark brown, opaque, one specimen rusty colored, dull (Figs 1-4).
Antenna moderately robust, wide; scape with elongate punctures; long, gently widening from base to apex, shorter than funicle and club combined; funicle slightly glossy, chestnut brown, compact, robust, articles three to five approximately equal in size; articles six and seven approximately equal in size, wider than long (Fig. 26); club glossy, chestnut brown (Figs 26, 27); club article 1 longer than others combined and glabrous; club articles 2 and 3 with yellowish, erect setae (Fig. 27), strongly compact, ovate.
Head oval, coarse, punctures nearly confluent in various circular and oblong shapes. Eyes dark brown to black, with coarse, convex facets (Fig. 25), widely separated dorsally, located laterally at base of rostrum. Temples swelling.
Scutellum fuscous, glossy, large. Elytra arcuate, basal margin slightly concave, apex gently rounded and emarginate laterally; striae with deep circular punctures, diameter longer than distance between punctures; intervals: with evenly shaped and distributed punctures; punctures with median keel dividing each puncture and with minute setae slightly off-center on keel (Fig. 28); first interval dilated behind declivity to apex, with fine punctures and appressed, minute setae from declivity to apex; intervals four and six connate and fused at declivity (Fig. 24); humeri convex, limited by striae six to eight and intervals six to nine. Sclerolepidia along dorsal margin of metaventrite appearing closer to digitate type 2A (Figs 31, 32), in which sclerolepidia are divided into two distinct lobes, with each lobe divided into several short digits (Lyal et al. 2006).
Female terminalia and genitalia (Figs 10-13). Gonocoxites of typical form; coxites oblong, somewhat quadrate; styli elongate, narrow. Spermatheca with globular base; apex strongly curved. Eighth tergite with slight rounded concavity along margin at middle and row of small setae along apical margin. Eighth sternite with base strongly bifurcate; spiculum short, approximately 0.5 × length of base.
Distribution. Guangdong Province, southern China. Host plant. The type series was collected from the tree Aleurites moluccana (L.) Willdenow (Euphorbiaceae), but it is not known if this is a larval host of the weevil.
Etymology. The specific epithet is a Latin past participle and used to refer to the punctate body of the species. Sexual dimorphism. No strong differences are apparent between sexes other than the slightly longer and narrower rostrum of the female and the concave first and second ventrites in the male.

Discussion
Pheude is the third monotypic cossonine genus described from China and differs from other oriental cossonine genera, which have been studied by Morimoto (1973), and other Dryotribini genera (e.g. Lixomimus Voss; Cotasteroloeblia Osella) distributed in adjacent countries (India, Nepal, and Japan) in having the following characters: rostrum nearly parallel-sided, rostrum without any keel ventrally, longer than wide (more than 2 × width), with a longitudinal furrow dorsally; head small; antenna inserted on basal one-third of rostrum; scape extending beyond hind margin of eye, funicle with seven articles; pronotum longer than wide, base bisinuate, with a longitudinal median crest from base to apex; scutellum visible; apical margin of elytra expanded and lower than level of venter, elytral apical margin gently rounded and flattened; third tarsomere entire. Also, Pheude differs from the Chinese genera Muschanella and Microtribodes by the following: Muschanella has a wider head, the rostrum widened towards apex, and the antennae inserted slightly before middle of rostrum. Microtribodes has an antennal funicle of five articles, the basal half of rostrum with a ventral keel, the antennae inserted before middle of rostrum, and tarsomere 3 bilobed.
The tribe Dryotribini is represented in China by five genera. All these genera are distributed in China and adjacent countries except Stenomimus, which is completely Nearctic and Neotropical in distribution, so is presumably introduced into China.
The available distribution of these genera can give an idea that the Chinese cossonine fauna still have so many genera beyond our thinking either to be recorded or to be discovered, so that much more efforts are required for collecting specimens and identification.