(Figs 8–15)
Material examined. Holotype, ♀, China, Yunnan prov., Yuxi City, Xinping County, Jiasa Town, Dabinlang Ecological Park, 24°2′21″N, 101°35′26″E, 523 m, 17.VII.2014, Xiaoqian Shi (YNAU); paratype, 1♀, China, Yunnan prov., Puer City, Simao County, Nanping Town, Xinfang Reservoir, 22°42′53″N, 100°57′41″E, 1342 m, 11.VII.2014, Xiaoqian Shi (YNAU).
Diagnosis. This species can be recognized by the following combination of characters: lower frons (Fig. 9) with medial longitudinal narrow groove and coarse punctures; pronotum latero-ventrally (Fig. 12) with irregular areolate sculpture; propodeal areola (Fig. 11) trapezoidal, strongly convergent posteriorly; subposterior area of T1 close to middle and (Fig. 14) medially with one transverse row of short longitudinal striae; tegula 2.1× longer than wide (Fig. 13); inner face of hind basitarsus medially with longitudinal groove.
Description. Female (Fig. 8). Body length 8.8–9.1 mm, forewing length 5.1–5.6 mm.
Color. Body almost black, with pale brown setae; mandible and flagellum reddish brown (Fig. 9); upper part of tegula (Fig. 13) dark brown and lower part brown; pterostigma, veins, tarsi and posterior of pygidium (Fig. 15) brown; wings (Fig. 8) infuscate.
Head. Mandible (Fig. 9) without distinct medial transverse groove and preapical denticle, atmost with obsolete intermittent impressed line; clypeus (Fig. 9) basally with coarse punctures and apically smooth, apex medially truncated; W: OW: L: IOD=10: 5.4: 6: 6.9; OOD: POD: Od=10: 7.8: 3.6; AOD: WAS: IAD: CL: CAW=10: 6: 3.6: 5.8: 6.2; lower frons (Fig. 9) with medial longitudinal narrow groove and coarse punctures, upper frons with relatively sparser punctures; vertex (Fig. 10) with sparse punctures, interspaces smooth; close to occipital carina with sparse punctures mixed with dense minute ones.
Mesosoma. Pronotal anterior carina incomplete, medially weak, anterior half of pronotum with dense punctures, posterior half impunctate; pronotum latero-ventrally (Fig. 12) with irregular areolate sculpture; mesoscutum medially with dense punctures, laterally with sparser ones, anterior medial groove separated from notaulus; mesopleuron (Fig. 12) anteriorly with dense big punctures, elsewhere with a few scattered and small punctures; along margins of mesoscutellum (Fig. 11) with big and dense punctures; metanotum posteriorly with a few big punctures mixed with some minute ones; horizontal area of propodeal dorsal face coriaceous (Fig. 11), oblique area densely pitted and with submarginal carina, posteriorly with short longitudinal striae connecting transverse carina; propodeal areola (Fig. 11) trapezoidal, strongly convergent posteriorly, APWL=4.5: 2.1: 8.2, medial longitudinal carina reaching posterior 3/5 of areola; lateral surface of propodeum dorsally with dense long oblique wrinkles, ventrally with a few minute punctures; posterior surface of propodeum granulate, without short medial longitudinal carina; tegula (Fig. 13) 2.1× longer than wide, posterior margin without transverse impressed line; second intercubital vein of forewing (Fig. 8) strongly sinuous; fore and mid tibiae with one spur apically, hind tibia with 2 spurs apically; inner face of hind basitarsus medially with longitudinal groove.
Metasoma. Anterior half of T1 (Figs 8, 14) with deep and dense punctures; subposterior area of T1 close to middle and with one transverse row of short longitudinal striae, posterior half impunctate; S1 with dense minute punctures, with posterolateral groove and reaching the anterior apex; T2 antero-laterally with costate transverse depression (Fig. 14), medially obsolete; T2 with irregularly dense punctures, postero-medially smooth, with sparse punctures; S2–S5 with irregularly dense punctures; pygidium (Fig. 15) anteriorly and medially with dense punctures, posteriorly coriaceous.
Male. Unknown.
Distribution. China (Yunnan).
Etymology. The specific name longistria is derived from the two latin words: long (= longitudinal) + stria (= striae), referring to subposterior area of T1 close to middle and medially with one transverse row of short longitudinal striae.