Baiocis orientalis Beaver & Liu, 2018

Beaver, Roger A., 2018, A review of the genus Baiocis Browne, 1962 (Coleoptera: Curculionidae: Platypodinae), with new species, new synonymy and a key to males, Zootaxa 4434 (3), pp. 481-501 : 485-487

Baiocis orientalis Beaver & Liu , new species

( Figs. 14, 17 , 26‒27 )

Male: 2.1‒2.5 mm long, 4.6‒5.1 times as long as wide, yellowish brown, the head and posterior third of the elytra darker, the basal half of the elytra paler, vestiture very sparse. Head with frons broadly, shallowly impressed between eyes, weakly granulate-punctate above epistoma and at sides, the punctures with short, erect hairs, the granules sparser in the middle of the frons and the surface alutaceous, median stria moderately long, the frons angularly separated from the vertex by a weak transverse ridge, a little behind this a transverse row of longer, backwardly curved hairs. Eye rounded, slightly longer than deep. Pronotum 1.5‒1.6 times longer than wide, widest behind deep femoral grooves, maximum width about 1.4 times minimum, disc smooth, shining, weakly alutaceous close to apical and basal margins, almost glabrous above, a few short hairs laterally, disc with rather poorly defined scattered punctures of variable size, median line extending from near base to just in front of narrowest part of pronotum. Elytra 2.5‒2.7 times as long as wide, 1.6‒1.7 times longer than pronotum, horizontal, the sides weakly convex, widest about middle, lacking a constriction posteriorly, the lateral margins with a series of serrations in the apical quarter, each serration with a single hair, disc smooth, shining, glabrous except for a row of hairs close to the lateral margin, and a few scattered hairs on the posterior third, striae not impressed, finely punctured, the punctures poorly defined near the base, more distinct towards the apex, interstriae not distinct, their punctures very fine and more widely spaced than on the striae, disc terminating apically in a carinate rim bearing short hairs, the rim forming a shallow re-entrant V, declivity narrow, lunate, concave, shining, posterolateral angle projecting as a short, acute tooth directed posterolaterally and ventrally, not visible from above. Abdomen with ventrite 1 strongly arched, its apical margin slightly projecting over ventrite 2, which is similar but less strongly arched, ventrites 3 and 4 with apical margin slightly thickened, ventrite 5 concave, a row of long hairs just before the apical margin of each ventrite except the last, which bears a single hair on each side near the lateral margin. Anterior margin of impression on metanepisternum and metaventrite with a rather weak costa on metanepisternum. Metacoxa with a small spine on its inner margin projecting posteriorly.

Female: 2.1‒2.6 mm long, 4.7‒5.1 times as long as wide, generally resembling male, but frons not granulate, more shining, more densely punctured, the punctures with longer hairs, not impressed above, somewhat angularly separated from vertex, but without a transverse ridge. Antennal club and eye relatively larger than in male. Pronotum 1.4‒1.5 times longer than wide, femoral grooves a little shallower, maximum pronotal width about 1.3 times minimum, surface alutaceous throughout, consequently less shining than in male. Elytra 2.6‒2.8 times as long as wide, 1.85‒2.0 times longer than pronotum, almost parallel-sided, declivity short, slightly concave, separated from disc at sides by a weak carina which does not extend to suture, declivital sulcus three to four times as wide as deep, densely covered with moderately long, erect hairs. Ventrites not thickened apically, fifth ventrite convex. Metanepisternum with costa represented only by a faint ridge. Inner margin of metacoxa without a spine.

Holotype: Male: MALAYSIA, Sabah, Sipitang , Mendolong. 2.iii.1989 (S.Adebratt). (Deposited in ZMLU)

Allotype: Female. As holotype, except 8.iii.1989. (Deposited in ZMLU)

Paratypes: 59 specimens: 9 males, 9 females: as holotype except various dates from 1.xii.1987, 19.iv.1988 ‒ 13.v.1988, 8.iii.1989 ‒ 16.iii.1989 (ZMLU, RAB); 5 males, 1 female: BRUNEI, Temburong, Nr. K. Belalong Field Stud. Centre , 4°33'N 115°09'E, 250-300 m, various dates from 1.ii.1992 ‒ 7.iii.1992 (R.A.Beaver) ( RAB) ; 4 males, 3 females: INDONESIA, Sulawesi Utara, Dumoga-Bone N.P., Plot C, ca. 400m, lowland forest, flight interception trap, various months from February‒April 1985 ( BMNH, RAB) ; 16 males, 4 females: LAOS-N, (Louangphrabang), 11‒21.v.2002, 19°35′N, 101°58′E, Thong Khan, ~ 750m, Vit Kubáň leg. ; 2 males, 1 female: LAOS, 1.‒16.v.1999, Louangphrabang pr., 20°33‒4′N, 102°14′E, Ban Song Cha (5km W), 1200m, Vit Kubáň leg. ; 1 male: as previous except: 10.‒16.v.1999 (NHMB, RAB); 2 males, 2 females: THAILAND, Chiang Mai, Mae Tang , 8.xi.1970 (R.A. Beaver) (previously determined as Baiocis pernanulus by F.G. Browne) ( RAB) .

Etymology: the Latin name orientalis is a masculine nominative adjective referring to the Oriental region, within which the species is widespread.

Diagnosis: This species was consistently misidentified by F. G. Browne as Baiocis pernanulus (Schedl) , and misidentified specimens are likely to be found in a number of museums. The true B. pernanulus he described under the name Baiocis solomonicus ( Browne 1986) . The male is most easily distinguished from B. pernanulus by the form of the elytral declivity. B. pernanulus belongs to the group of species in which the apical part of the elytral disc is somewhat matt and granulate, the elytral emargination is very shallowly U-shaped, with the basal margin nearly straight, the apical rim is rounded, and does not project over the declivity, while the posterolateral tooth of the elytron is visible from above. In contrast, in B. orientalis , and species related to it, the apical part of the elytral disc is smooth and shining, the elytral emargination is shallowly V-shaped, the elytral rim is carinate and projects over the declivity, and the posterolateral tooth of the elytron is concealed from above. In the female of B. pernanulus , the frons is angularly separated from the vertex by a distinct, continuous transverse ridge or carina, but in B. orientalis there is no ridge, and the frons curves more evenly into the vertex. B. orientalis is most closely related to B. unispineus Roberts. In the male, it can be distinguished from that species by the short posterolateral tooth of the elytra, and the declivital sulcus narrower vertically relative to its width across elytra, about 5 times wider than deep rather than 4 times. The second ventrite lacks a humped transverse ridge across the middle. The male is 2.1‒2.5 mm long relative to 2.8‒2.9 mm in B. unispineus . The females are easily distinguished only by size, 2.1‒2.6 mm in B. orientalis , 3.0‒ 3.1 mm in B. unispineus . B. orientalis is apparently more variable in size and proportions than most of the remaining species of Baiocis , but this may be partly because a greater number of specimens has been available for study. The total geographical range of the species is uncertain because of earlier misidentifications, but probably extends beyond the area from Thailand to Sulawesi.

Biology: It is likely that records given for B. pernanulus by Browne (1961, 1984), Ohno et al. (1987a, b) and Ohno (1990) should be referred to this species. If this is correct, then the species has been recorded from numerous families of trees, and shows no particular host preferences.

Figures

FIGURES 10–17. Baiocis species. 10. B. angustiformis, dorsal view male elytral apex. 11‒12. B. inimicus. 11, dorsal view male elytral apex; 12, lateral view male abdomen and elytral apex. 13. B. pernanulus, dorsal view male elytral apex. 14, 17. B. orientalis. 14, male elytral apex, posterior view; 17, male head, lateral view. 15. B. unispineus, lateral view male abdomen and elytral apex. 16. B. pernanulus, lateral view female head. Scale line = 0.67 mm (Figs 11‒12, 15); 0.5 mm (Figs 10, 13, 16‒17); 0.4 mm (Fig. 14)

FIGURES 26–32. Baiocis species. 26‒27. B. orientalis dorsal view: 26, male (2.3 mm); 27, female (2.4 mm). 28. B. pernanulus male (2.3 mm), dorsal view. 29. B. sumatranus male (3.5 mm), dorsal view. 30‒32. B. laosi. 30, male (2.9 mm), dorsal view; 31, female (3.0 mm), dorsal view; 32, male abdomen, lateral view.