Polemistus clypeisinuatus 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 : 477-478

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

( Figure 1 )

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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.

Figures

FIGURE 1 Polemistus clypeisinuatus Ma et Li, sp. nov. (Holotype, male). a. Frontal view of head; b. Dorsal view of head; c. Ventral view of antennal segments I–XIII; d. Dorsal view of propodeum; e. Mesopleuron; f. Dorsal view of petiole and gastral tergum I; g. Dorsal view of male genitalia; h. Lateral view of male genitalia; i. Lateral view of gonostyle (scale line for e: 1 mm; for b: 1.25 mm; for a, d and f: 1.31 mm; for c, g–i: 1.63 mm).