Perileptus pusilloides Deuve and Liang, 2016

Deuve, Thierry, Kavanaugh, David H. & Liang, Hongbin, 2016, Inventory of the Carabid Beetle Fauna of the Gaoligong Mountains, Western Yunnan Province, China: Species of the Tribe Trechini (Coleoptera: Caraboidea), with Descriptions of Four New Genera, One New Subgenus and 19 New Species., Proceedings of the California Academy of Sciences 63 (12), pp. 341-455 : 348-352

Perileptus pusilloides Deuve and Liang sp. nov.

( Figs. 6 , 46–48 )

TYPE MATERIAL.— Holotype, a male, in IOZ, labeled: “CASENT 1039259”/ “ CHINA, Yunnan, Tengchong County, Hehua Township, 5.4 km S of Hehua at Dengman village along Daying Jiang , N24.92346° / E98.38612°,”/ “ 1105 m, 2 June 2006, Stop # DHK-2006-053, D.H. Kavanaugh , R.L. Brett & D.Z. Dong collectors”/ “ HOLOTYPE Perileptus pusilloides Deuve & Liang , sp. nov. designated 2016” [red label] . Paratypes (a total of 4): 2 males and 1 female (in CAS, IOZ, MNHN)

labeled same as holotype except first label “CASENT 1039257” and “CASENT 1039260” and “CASENT 1039258”, respectively; 1 female (in IOZ) labeled: “CASENT 1036294”/ “ CHINA, Yunnan, Longyang County, Bawan Township, Kunhong He at Bingmen , N25.09065° / E98.83721°,”/ “ 680 m, 1 June 2005, Stop# 2005-039, D.H. Kavanaugh & H.B. Liang collectors”. All paratypes also bear the following label: “ PARATYPE Perileptus pusilloides Deuve & Liang , sp. nov. designated 2016” [yellow label] .

TYPE LOCALITY.— China, Yunnan, Tengchong County, Hehua Township, 5.4 km S of Hehua at Dengman village along Daying Jiang , N24.92346° / E98.38612°, 1105 m .

ETYMOLOGY.— The species epithet, pusilloides , is a combination of the species epithet, pusillus , and the Greek suffix, –ΕΙδής (transliterated into Latin as –oides), meaning resembling, in reference to the similarity of members of this species to those of T. pusillus Jeannel (1923) .

DIAGNOSIS.— Adults of this species ( Fig. 6a ) can be distinguished from those of all other species in the region by the following combination of character states: size very small (BL = 2.3 mm), fully-winged; body color light yellowish brown, elytra concolorous throughout; microsculpture of elytra irregularly isodiametric and moderately impressed; dorsal pubescence dense and rather short; pronotum slightly transverse (ratio PW/PL = 1.32) only slightly convex, with lateral margins moderately rounded in anterior half, straightened just anterior to basal angles, the latter acute and sharp but small, median basal area rugulose; elytra alutaceous, distinctly flattened, striae finely punctate.

DESCRIPTION.— Size very small, BL = 2.3 mm. Color of dorsum pale yellowish brown, head and pronotum slightly pale reddish in some specimens, appendages pale yellow, antennomeres 3 to 11 slightly darker yellowish brown; dorsal surface covered with dense but short pubescence.

Head. Relatively large, with eyes large and convex. Tempora very short. Frons flattened, nearly smooth, shiny but finely punctate; frontal furrows arcuate and deeply impressed to posterior margin of tempora; two pairs of supraorbital setae present and distinctly longer than setae of pubescence. Labrum broad with apical margin distinctly emarginate or concave. Mandibles small, slen- der. Mentum deeply concave, with median tooth broad and truncate. Submentum with a transverse row of ten setae anteriorly. Gula broad. Antennae of moderate length, antennomeres 2 and 3 of equal length.

Pronotum. Slightly transverse (ratio PW/PL = 1.32) and flattened, widest at anterior one-fourth, with lateral margins markedly rounded anteriorly, less so posteriorly, briefly and deeply sinuate just anterior to basal angles, the latter acute and sharp but small; basal margin projected posteriorly as a short, truncate lobe medial to lateral sinuations. Disc moderately punctate, flattened medially and slightly convex laterally; median basal area rugulose, only faintly defined anteriorly; median longitudinal impression distinct throughout, narrow anteriorly, widened toward base. Lateral margination slender throughout, slightly reflexed dorsally. One lateral seta (at anterior one-fifth) and one basolateral seta (on basal angle) present on each side.

Elytra. Alutaceous, moderately elongate, with humeri very distinct, rectangular but broadly rounded; elytral disc flattened, only moderately convex laterally; lateral margination slender and slightly reflexed dorsally; basal margin terminated medially at the origin of stria 5; striae 1 to 4 or 5 dinstinctly impressed and moderately punctate, striae 5 or 6 to 8 effaced. Recurrent stria absent. Umbilicate setal series with setae of humeral group equidistance from each other, those of the median group inserted posterior to middle.

Legs. Short. Male protarsomeres 1 and 2 dilated and apicomedially toothed.

Venter. Ventral surface of head and thoracic pleurae, prosternum, metasternum, metepisterna and abdominal ventrites punctate. Pubescence denser on abdominal ventrites than on thoracic venter.

Male aedeagus. Median lobe ( Fig. 6b ) with apex narrowly lobate, apically rounded.

COMMENTS.— Based on features of form and structure, this species appears to be closely relat- ed to P. pusillus , described from northern Vietnam. Its members can be distinguished from those of the latter in having their elytra wider, less shiny, more alutaceous, and with more finely punctate striae, and the pronotum relatively larger, with a less smooth surface, and with the greatest pronotal width more anterior. The type series of P. pusillus originally consisted of ten syntypes, seven of which are in the Jeannel Collection in MNHN, each with a “Type” label. Among these, six specimens match Jeannel’s description of P. pusillus very closely. The seventh specimen, a male, instead may be a member of our new species, P. pusilloides . Consequently, in order to properly establish the identity to P. pusillus , we here designate a lectotype as follows: a male, in MNHN, labeled: “ Hoa Binh, Tonkin ”/ “ Perileptus pusillus Jeannel , lectotype, design. 2016, ex coll. R. Jeannel, in coll. MNHN, Paris”. The remaining six MNHN syntypes are all paralectotypes of P. pusillus , including the lone possible male of P. pusilloides , which we are not including in the type series of the latter species.

HABITAT DISTRIBUTION.— Members of this species have been found in daytime on sandy flats, in gravel and under stones along the open, unshaded banks of small to large streams running through agricultural areas with subtropical crops at elevations ranging from 680 to 1105 m. Most specimens were driven from their hiding places by splashing the banks with water from the stream. At the collecting site in Longyang County (see below), members of this species were found syntopic with members of Perileptus imaicus .

GEOGRAPHICAL DISTRIBUTION WITHIN THE GAOLIGONG SHAN.— Fig. 6c . We examined a total of 5 specimens (3 males and 2 females) from low elevations on both western and eastern slopes of the southern part of the Gaoligong Shan in Tengchong and Longyang Counties , (see Type material above for exact collection data), which are in Core Areas 6 and 7, respectively .

OVERALL GEOGRAPHICAL DISTRIBUTION.— This species currently is known only from the southern part of the Gaoligong Shan region in western Yunnan Province, China.

Figures

FIGURE 6. Perileptus pusilloides sp. nov.; a. Dorsal habitus (CASENT1039260). b. Median lobe of aedeagus of male (CASENT1039259), left lateral aspect. c. Map of locality records (red circles) for P. pusilloides in the Gaoligong Shan region. Scale lines a, b = 0.5 mm, c = 100 km.

FIGURE 46. Chart showing the representation of trechine species in project-designated Core Areas (see Fig. 3) in the Gaoligong Shan region.

FIGURE 47. Chart illustrating the altitudinal ranges of trechine species represented in the Gaoligong Shan region.

FIGURE. 48. Chart illustrating the co-occurence (syntopy) of trechine species in samples from the same habitats and at the same sites in the Gaoligong Shan region.