Polemistus pediflavidus Ma et Li, 2020

Ma, Li & Li, Qiang, 2020, The genus Polemistus de Saussure in China with descriptions of four new species (Hymenoptera: Crabronidae), Zootaxa 4852 (4), pp. 475-484 : 482-483

4. Polemistus pediflavidus Ma et Li , sp. nov.

( Figure 4 )

urn:lsid:zoobank.org:act:D935CE7E-8F67-4930-A5EA-03748A01F2AE

Material examined. Holotype: ♀, China: Yunnan: Jinghong: Xishuangbanna National Forest Park, 21°58'N 100°51'E, 2003.VII.31, coll. Peng Wang ; Paratype: 8 ♀, same data as the holotype, 2003.VII.31, coll. Peng Wang, Zhenshan Geng, Tingjing Li, Qian Jiang. All specimens are deposited in the Insect Collections of Yunnan Agricultural University, Kunming, Yunnan Province, P. R. China .

Diagnosis. Unlike the other Chinese Polemistus , this species and P. sumatrensis lack the hypersternaulus, and have a short frontal median carina, a round or triangular labrum, and a triangular lateral teeth on clypeus. P. pediflavidus differs from P. sumatrensis ( Maidl, 1925) by the following combination of characters: labrum round; clypeus with a strong triangular lateral tooth on each side ( Fig. 4a ); gena near mandible base without rugae; underside of head coarsely coriaceous, and with fine, dense punctures, without rugae; mesoscutum without rugae posteriorly; mesopleuron coarsely coriaceous, posteriorly with dense, short, longitudinal rugae; propodeal enclosure without delimiting carina ( Fig. 4c ); dorsal surface of petiole without groove ( Fig. 4e ).

P. sumatrensis ( Maidl, 1925) is characterized as follows: labrum triangular; clypeus with small triangular lateral tooth on each side; gena near mandible with dense, sturdy, transverse rugae; underside of head distinctly coriaceous, densely, conspicuously, longitudinally rugose; mesoscutum with dense, short, longitudinal rugae posteriorly; mesopleuron finely coriaceous, not rugose posteriorly; propodeal enclosure well defined by U-shaped carina; dorsal surface of petiole with longitudinal groove medially.

Description. Female. Body length 4.5–5.5 mm. Black; apical third of mandible and labrum reddish brown; palpi yellow; scape ivory to yellowish; pedicel, tegula, and forewing veins fulvous; flagellomeres I–IX beneath and flagellomere I above reddish brown; pronotal lobe ivory; legs yellowish to reddish brown except coxae black. Setae on clypeus sparse, short, silvery.

Mandible bidentate apically, outer tooth small, inner tooth broad and truncate ( Fig. 4a ). Labrum round. Clypeus flat, with fine, dense punctures, free margin nearly truncate medially, laterally with large, triangular tooth ( Fig. 4a ). Interantennal tubercle narrow, short. Median and lower frons slightly concave, lower frons with short, slender frontal median carina ( Fig. 4a ), densely, transversely striate medially, lateral area and median frons with contiguous, large punctures and dense, sturdy and curving rugae. Upper frons with midsize to large, dense punctures. Ocellar triangle slightly convex, with midsize, dense punctures. Vertex behind ocelli with fine, dense punctures, densely, finely, transversely striate. Gena with large, contiguous punctures, coarsely coriaceous. Head underside coarsely coriaceous, finely, densely punctate. Occipital furrow much narrowed, distinctly crenate. Inner orbital furrow narrow, marginal carina sturdy, finely crenate, inner orbits markedly convergent toward clypeus ( Fig. 4a ). Outer orbital furrow narrow, marginal carina sturdy, coarsely crenate. Ratio of HW: HLD: HLF = 71: 34: 68; HW: EWd: IOW: EW: OOW: TW: OCW: EL = 71: 18: 3: 25: 1: 17: 1: 62; AOD: WAS: IAD = 3: 6: 6; POD: OOD: OCD = 9: 9: 13. Length of scape: of pedicel: of flagellomere I: width of flagellomere I: length of flagellomere II: width of flagellomere II = 28: 6: 6: 5.5: 6: 6.

Pronotal collar incomplete, with just lateral corner. Mesoscutum coarsely coriaceous, with contiguous, midsize punctures, anterior slope nearly vertical and very high; admedian line impressed, extending to one fourth of mesoscutum length; notaulus shallowly grooved and crenate, reaching one third of mesoscutum length; parapsidal line slightly impressed. Scutellum coarsely coriaceous, with midsize, dense punctures. Metanotum coarsely coriaceous, finely, densely punctate. Mesopleuron coarsely coriaceous, with midsize to large, dense punctures, posteriorly with dense, short, slender, longitudinal rugae, scrobal sulcus shiny, omaulus and episternal sulcus distinctly crenate, hypersternaulus lacking ( Fig. 4d ). Propodeal enclosure without delimiting carina, medially with sturdy reticulation, laterally with sparse, slender, oblique longitudinal rugae ( Fig. 4c ); posterior surface with narrow groove medially, shiny, sides of groove large, nearly smooth, with fine, sparse punctures and some inconspicuous striae or finely coriaceous ( Fig. 4c ), laterally and posteriorly irregularly reticulate. Lateral surface of propodeum with dense, sturdy, longitudinal rugae except irregularly rugose ventrally and reticulate posteriorly.

Petiole short, slightly longer than wide, dorsal surface shiny, smooth ( Fig. 4e ). Gastral segments half mat, with fine, dense punctures, finely coriaceous. Gaster somewhat constricted between segments I and II. Pygidial area lacking.

Male. Unknown.

Distribution. China (Yunnan).

Etymology. The name, pediflavidus , is derived from the Latin words pes, genitive pedis (= leg) and flavidus (= yellowish), referring to the legs yellowish to reddish brown except coxae black, one of the main recognition characters of this species.

Figures

FIGURE 4 Polemistus pediflavidus Ma et Li, sp. nov. (Holotype, female). a. Frontal view of head; b. Dorsal view of head; c. Dorsal view of propodeum; d. Mesopleuron; e. Dorsal view of petiole and gastral tergum I (scale line for b and d: 1 mm; for a, c and e: 1.31 mm).