Polemistus de Saussure, 1892

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 : 476-477

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.