Polemistus clypeisinuatus Ma et Li 2020, sp. nov.

1. Polemistus clypeisinuatus Ma et Li, sp. nov.

(Figure 1)

urn:lsid:zoobank.org:act: 4412BA24-406F-4E54-8D27-EA47B26E1562

Material examined. Holotype: ♂, China: Zhejiang: Longquan: Fengyang Mount, 27°54'N 119°10'E, 2003.VIII.10, NO. 200707979, coll. Jingxian Liu. The specimen is deposited in the Parasitic Hymenoptera Collection of Zhejiang University, Hangzhou, Zhejiang Province, P. R. China.

Diagnosis. Unlike the other Chinese Polemistus, this species and P. fukuitor have the frontal median carina and the hypersternaulus, the free margin of the clypeus truncate or sinuate medially; and the inner orbits conspicuously convergent toward the clypeus.

P. clypeisinuatus differs from P. fukuitor Tsuneki (1992) by the following combination of characters: pronotal lobe dark brown; free margin of clypeus sinuate (Fig. 1a); ocellar triangle markedly convex (Fig. 1b); notaulus shallowly grooved and crenate, reaching one third of mesoscutum length; mesopleuron shiny, slightly leather-like, with sparse, fine punctures; dorsal surface of petiole without groove (Fig. 1f); gastral segments I–II shiny, with fine, sparse punctures; male flagellomeres I–V beneath with long triangular tyloids (Fig. 1c).

P. fukuitor Tsuneki (1992) has the following characters: pronotal lobe ivory to yellowish; free margin of clypeus truncate medially, lateral area with triangular tooth; ocellar triangle moderately convex; notaulus lacking; mesopleuron coarsely coriaceous, with midsize to large, dense punctures; dorsal surface of petiole with longitudinal groove; gastral segments I–II half mat, with fine dense punctures, slightly coriaceous; male flagellomeres I–V each with a curved seta at base near ventral side.

Description. Male. Body length 3.7 mm. Mandible apically reddish brown; labrum dark brown; palpi ivory; antenna above and pronotal lobe dark brown, scape beneath ivory, pedicel beneath yellowish, flagellum beneath, tegula, and forewing veins fulvous to brown; fore and mid legs: trochanters, base and apex of femora and tibiae fulvous, tarsi ivory, remainder of femora reddish brown; hind leg: trochanter and basal half of tibia fulvous, tibia apically and tarsus reddish brown to dark brown; gastral sterna dark brown. Setae on clypeus dense, short and silvery.

Mandible bidentate apically, teeth blunt, outer tooth larger than inner one. Labrum triangular (Fig. 1a). Clypeus flat, with fine dense punctures, free margin sinuate (Fig. 1a). Interantennal tubercle narrow, short. Median and lower frons slightly concave; lower frons with slender frontal median carina (Fig. 1a) and slender, dense, transverse striation medially, laterally with sturdy, dense longitudinal rugae; median frons with large, dense punctures and several inconspicuous, curving rugae. Upper frons with midsize to large, sparse punctures. Ocellar triangle markedly convex (Fig. 1b), with sparse, midsize punctures medially, slightly coriaceous laterally. Vertex behind ocelli with dense, slender, transverse striation. Gena and head underside distinctly coriaceous. Occipital furrow much narrowed, conspicuously crenulated (Fig. 1b). Inner orbital furrow narrow, with distinct marginal carina, slightly crenate, inner orbits conspicuously convergent toward clypeus (Fig. 1a). Outer orbital furrow much narrowed, marginal carina distinct dorsally, inconspicuous ventrally, coarsely crenate. Ratio of HW: HLD: HLF = 61: 29: 54; HW: EWd: IOW: EW: OOW: TW: OCW: EL = 61: 17: 2: 21: 1: 13: 44; AOD: WAS: IAD = 3: 6: 4; POD: OOD: OCD = 10: 9: 10. Length of scape: of pedicel: of flagellomere I: width of flagellomere I: length of flagellomere II: width of flagellomere II = 18: 5: 5: 5: 5: 5.5. Male flagellomeres I–V beneath with long, triangular tyloids, on VI tyloid inconspicuous (Fig. 1c).

Pronotal collar much narrowed, without anterior ridge, shiny, smooth. Mesoscutum coarsely coriaceous, with contiguous, large punctures, anterior slope nearly vertical and very high, posteriorly without rugae; admedian line impressed, extending to one third of mesoscutum; notaulus shallowly grooved and crenate, reaching one third of mesoscutum length; parapsidal line inconspicuously impressed. Scutellum coarsely coriaceous, with large, dense punctures. Metanotum coarsely coriaceous, with fine, dense punctures. Mesopleuron shiny, minutely coriaceous, with sparse, fine punctures; episternal sulcus and omaulus distinctly crenate, scrobal sulcus shiny, incomplete, hypersternaulus very short, crenate (Fig. 1e). Propodeal enclosure without bordering carina, median area coarsely reticulate, lateral area with sparse, slender, oblique longitudinal rugae (Fig. 1d); posterior surface with much narrowed median groove, shiny, sides of groove large, with large, sparse punctures and several irregular rugae, irregularly rugose laterally and posteriorly (Fig. 1d). Lateral surface of propodeum with dense, slender, longitudinal rugae.

Petiole slightly wider than long, dorsal surface shiny, smooth (Fig. 1f). Gastral segments I–II shiny, with fine, sparse punctures, segments III–VI half mat, slightly coriaceous and with fine, dense punctures. Gaster somewhat constricted between segments I and II. Male genitalia (Figs. 1 g–i).

Female. Unknown.

Distribution. China (Zhejiang).

Etymology. The name, clypeisinuatus, is derived from the Latin stem clype - (= clypeus) and the Latin word sinuatus (= sinuate), referring to the free margin of clypeus sinuate medially, one of the main recognition characters of this species.