The genus Polemistus de Saussure in China with descriptions of four new species (Hymenoptera: Crabronidae) Author Ma, Li 0000-0002-3436-1387 Department of Entomology, College of Plant Protection, Yunnan Agricultural University, Kunming, Yunnan, 650201, P. R. China. & maliwasps @ aliyun. com; https: // orcid. org / 0000 - 0002 - 3436 - 1387 maliwasps@aliyun.com Author Li, Qiang Department of Entomology, College of Plant Protection, Yunnan Agricultural University, Kunming, Yunnan, 650201, P. R. China. text Zootaxa 2020 2020-09-17 4852 4 475 484 journal article 8417 10.11646/zootaxa.4852.4.5 d9a2f10f-7a8b-42b8-8b07-2495ab5b25ee 1175-5326 4410119 486DDE4C-8301-41C7-85EA-57AC12ABB617 Key to the species of Polemistus de Saussure from China (Female, Male) 1. Frontal median carina absent; hypersternaulus lacking........................................................ 2 - Frontal median carina present; hypersternaulus lacking or crenate............................................... 3 2. Mesoscutum with short, longitudinal rugae posteriorly; dorsal surface of petiole without groove; in female, free margin of clypeus with large prominence on each side; in male, flagellomeres I–VIII or IX beneath with tyloids... P. abnormis (Kohl) - Mesoscutum without rugae posteriorly; dorsal surface of petiole with longitudinal groove medially; in female, free margin of clypeus with small tooth on each side; in male, flagellomeres I–VI beneath with tyloids.............. P. gutianus sp. nov. 3. Hypersternaulus present, distinctly crenate................................................................. 4 - Hypersternaulus lacking................................................................................ 7 4. Mesoscutum with six rows of large pits, anterior slope normal; petiole distinctly longer than wide; upper frons with conspicuous longitudinal and oblique carina.................................................... P. mindanaonis Tsuneki - Mesoscutum with contiguous, midsize to large punctures, without rows of pits, anterior slope nearly vertical and very high; petiole equal to or slightly longer than wide; upper frons without carina.......................................... 5 5. Vertex with strong transverse carina on each side, connecting hindocellus to orbital furrow; free margin of clypeus markedly produced, forming long, triangular tooth medially; inner orbit slightly convergent toward clypeus; male unknown............................................................................................ P. divaricatus sp. nov. - Vertex without carina; free margin of clypeus truncate or sinuate medially; inner orbits conspicuously convergent toward clypeus................................................................................................. 6 6. Free margin of clypeus truncate medially, lateral area with triangular tooth on each side; mesopleuron coarsely coriaceous, with midsize to large, dense punctures; dorsal surface of petiole with 2–3 longitudinal grooves; in male, flagellomeres I–V each with curved seta at base near ventral side........................................................ P. fukuitor Tsuneki - Free margin of clypeus sinuate; mesopleuron shiny, slightly leather-like, with sparse, fine punctures; dorsal surface of petiole without groove; in male, flagellomeres I–V beneath with long triangular tyloids; female unknown..................................................................................................... P. clypeisinuatus sp. nov. 7. Female: gaster distinctly constricted between segments I and II; labrum rectangular; free margin of clypeus with large prominence on each side (male unknown)....................................................................... 8 - Female: gaster slightly constricted between segments I and II; labrum round or triangular; free margin of clypeus with triangular lateral teeth (male unknown).......................................................................... 9 8. Posterior surface of propodeum broadly and finely coriaceous medially, nearly smooth; lateral surface of propodeum coarsely reticulate dorsally and posteriorly; gastral tergum with sparse, tiny punctures..................... P. formosus (Tsuneki) - Posterior surface of propodeum with fine, dense and transverse rugae medially; lateral surface of propodeum with oblique rugae dorsally and posteriorly; each gastral tergum with midsize punctures medially and posteriorly except tergum I impunctate..................................................................................... P. alishanus (Tsuneki) 9. Propodeal enclosure well defined by broadly U-shaped carina; dorsal surface of petiole with longitudinal groove medially; posterior area of mesoscutum with dense, sturdy, longitudinal rugae........................... P. sumatrensis (Maidl) - Propodeal enclosure carina lacking; dorsal surface of petiole without groove; posterior area of mesoscutum without rugae; male unknown.......................................................................... P. pediflavidus sp. nov.