Diapus orientalis, Knížek, M., Beaver, R. A. & Liu, Y., 2015

Knížek, M., Beaver, R. A. & Liu, Y., 2015, A new species of Diapus Chapuis from South-West China and North Thailand (Coleoptera: Curculionidae: Platypodinae), Zootaxa 4058 (2), pp. 296-300 : 297-299

Diapus orientalis n. sp. (Figs 1–6, 8)

Male: 4.0– 4.4 mm long (4.1 in holotype), 2.9–3.0 times as long as wide (2.9 in holotype).

Colour: Head black, pronotum dark brown, base of elytra yellowish becoming dark brown posteriorly, antennal scape and first two segments of funicle and legs yellow, segments 3–5 of antennal funicle and club black.

Head: Frons flat, dull, irregularly punctured with large and small punctures, largest and densest above epistoma, bearing moderately long, upwardly curved, semierect hairs on upper part of frons; median line raised between antennal insertions which are located at sides of frons about 2/5 from the epistoma margin. Antennal scape clavate with scattered hairs, a few much longer, forwardly directed hairs in apical half; club oval, narrow testaceous strip present on outer margin, median testaceous strip absent.

Pronotum: 1.0–1.1 times longer than wide (1.0 in holotype), shining, alutaceous, with a few scattered fine punctures, a row of semierect backwardly pointed hairs close to anterior margin and anterolateral parts mainly, median line extending about 1/3 from base; a band of numerous, small mycangial pores extending 9/10 of width of pronotum at its base, the band 5–7 pores deep antero-posteriorly.

Scutellum: triangular, depressed below level of elytra, with a median longitudinal groove between lateral carinae.

Elytra: 1.8–2.0 times as long as wide (1.9 in holotype). 2.0–2.2 times as long as pronotum (2.1 in holotype), widest about 2/3 from base then slightly narrowed; disc with interstriae 1 carinate for most of its length, running directly onto declivity without a spine at discal apex; interstriae 2 forming a very fine carina, ending in a minute spine at discal apex; interstriae 3, 5 and 7 raised and more broadly carinate, tapering towards apex, each ending in a long, sharply pointed spine extending over declivity, and beyond elytra apex, spines on interstriae 5 and 7 equal in length and usually slightly longer than spine on interstriae 3; interstriae 4 and 6 flattened, ending in minute spines at discal apex; interstriae 7 and 8 fused at apex of disc; striae impressed, with fine, widely spaced punctures; declivity obliquely sloping, apex transverse, with 2 very large spines beneath interstriae 5 extending well beyond the spines on intertriae 3, 5, 7; vestiture of scattered, long hairs, more abundant and longer at tips of longer spines, and minute strial and interstrial hairs.

Metaventrite: with a row of stiff, short, setae along anterior margin of metaventral impression.

Abdomen: Abdominal ventrites 2 to 4 moderately finely punctured, each with irregular rows of erect posteriorly curved hairs, longest on ventrite 4; ventrite 5 as long as ventrites 2 to 4 together, strongly concave, dull, sparsely punctured with a few long hairs on surface and at margins.

PLATE 1. Dorsal and lateral views of Diapus orientalis n. sp. Figures 1–2. Male. Figures 3–4. Female.

PLATE 2. Head of Diapus orientalis n. sp. and Diapus quadrispinatus Chapuis. Figure 5. D. orientalis anterior view of male head. Figure 6. D. orientalis anterior view of head of young female with hair brushes. Figure 7. D. quadrispinatus postero-dorsal view of head of young female showing Y-shaped antennal scape and hair brushes. Figure 8. D. orientalis anterior view of head of old female without hair brushes. Figure 9. D. quadrispinatus anterior view of head of young female with hair brushes. Figure 10. D. quadrispinatus anterior view of head of female with hair brushes partially removed.

Female: 4.3–4.7 mm long (4.3 mm in allotype), 3.0–3.2 times as long as wide (3.0 in allotype).

Colour: Similar to male, but elytra brown becoming darker towards apex.

Head: Frons flat, sub-shining, coarsely punctured, lower half more shining and with a median carina separating a very shallow impression on each side concealed below frontal hairs; lateral to the impression on each side, a large, deep, circular fovea; sides of epistoma and frons below antennal insertions with long, forwardly-directed hairs, the hairs denser and forming a distinct brush of long, forwardly directed hairs curving ventrally and medially at level of antennal insertions. Mandibular appendages absent. Antennae inserted on lateral edges of frons at level of upper end of median carina and lower part of eyes; scape very broadly widened, the basal half bearing dense, fairly short, forwardly directed hairs, largely concealed below a thick, ventrally and medially curved brush of much longer hairs on the upper half; second funicular segment much longer than in male; club resembling that of male.

Pronotum: 1.1 times longer than wide. Similar to male, including the band of mycangial pores, but lateral emarginations deeper.

Elytra: 2.0–2.1 times as long as wide (2.0 in allotype). 2.0–2.2 times as long as pronotum (2.0 in allotype). Striae impressed, dull; interstriae convex, shining; interstriae 2, 4, and 6 not reaching apex of disc; interstriae 3, 5, and 7+8 ending rather abruptly at apex of disc, apex of disc and declivity sulcate at suture; declivity short, vertical, irregularly rugose, dull, sparsely hairy, without spines, apex transverse.

Abdomen: Similar to male, but the fifth ventrite weakly convex, shining

Type material. Holotype: male, CHINA, Yunnan, 1-19.VII.; HEISHUI 27.13N 100.19E; 35 km N of Lijiang; lgt. S. Becvar, 1992. (Deposited in National Museum, Prague).

Allotype: female, the same data as holotype. (Deposited in National Museum, Prague)

Paratypes: 42 specimens: 8 males, 5 females: same data as holotype (1 male, 1 female in in Naturhistorisches Museum, Wien; 7 males, 4 females in M. Knížek’s collection); 4 males, 1 female: CHINA, SICHUAN, 1991; LIZIPING, Shimian; 200km SW YA’AN; Kejval lgt., 27.VI.–3.VII.; 3 males: THAILAND bor.; Doi Inthanon Nat. Res.; 19.-21.- V.2008, 2550m; S. Murzin leg. (all in M. Knížek’s collection); 12 males, 8 females: Chiang Mai, Doi Inthanon NP, 18°35.361'N, 98°29.157'E, summit forest, 2500 m, malaise trap, various dates from 29.vi.–15.xii.2006, 29.iv.–6.v.2007, Y. Areeluck leg. (6 males, 4 females in Division of Entomology, Queen Sirikit Botanic Garden, Chiangmai; 3 males, 2 females in Natural History Museum, London; 3 males, 1 female in R. A. Beaver’s collection); 1 female: as previous except: Kew Mae Pan, 18°33.163'N, 98°28.8'E, 2200 m, malaise trap, 5–12.x.2006, Y. Areeluck leg. (in R. A. Beaver’s collection)

Diagnosis. Diapus orientalis is similar to D. quadrispinatus , and both males and females will key to that species ( Beaver 2002). It can be distinguished from the latter species using the following key:

1 Male: frons with a division between a lower, more shining, more strongly punctured area of variable extent above epistomal margin, and a larger, matt, smoother area with scattered small punctures above; antennal club with a long median testaceous strip lacking sensillae on anterior face; elytral declivity steep, due to very long spines on ending of interstriae 3, 5 and 7, the pair of large declivital spines only slightly longer than those on apex of elytral disc. Female: Antennal scape Y-shaped (Fig. 7) when viewed from in front, its inner (median) margin concave, the basal half with a medianly directed flange with a broadly rounded apex; lower half of frons with impressions on either side of median carina deeper (Fig. 10); middle part of frons above carina very sparsely punctured; brushes of hairs on lateral margin of frons, and below apex of scape less dense (Fig. 9) .................................. ....................................................................................................................................................................... quadrispinatus Chapuis

– Male: frons weakly shining throughout without a division into lower, shining and upper, matt areas, with strong punctures on both upper and lower parts (Fig. 5); antennal club without a median testaceous strip lacking sensillae on anterior face; elytral declivity more oblique, due to shorter spines on ending of interstriae 3, 5 and 7, the pair of large declivital spines much longer than those on apex of elytral disc. Female: Antennal scape very broadly widened, not Y-shaped, its inner margin slightly convex (Fig. 8); lower half of frons with very shallow impressions on either side of median carina; middle part of frons above carina more densely punctured (Fig. 8); brushes of hairs on lateral margin of frons, and below apex of scape much thicker (Fig. 6). ..... orientalis n. sp.

Etymology. The Latin species name refers to its eastern distribution.

Biology. Unknown. Some Thai specimens were taken from malaise traps, and specimens from Sichuan were dissected from wood of an unknown tree species. The biology is likely to be similar to other species of the genus (see above, and Browne 1961, Roberts 1993, Beaver 2000). As with D. quadrispinatus , it is likely to be polyphagous ( Beaver & Liu 2013).

Distribution. D. orientalis has a slightly more easterly distribution than D. quadrispinatus . The latter is known from Northeast India, Nepal, Bhutan and Myanmar between approximately 84o–95o E. The currently known collection sites of D. orientalis lie between 98o–100o E. Like D. quadrispinatus it appears to be a montane species. In Thailand, it is apparently confined to the peak of the highest mountain in the country (Doi Inthanon) at 2200–2500 m altitude, with all except one specimen collected at the higher altitude.