Pareumenes, de Saussure, 1855

Nguyen, Lien Thi Phuong, 2020, A new Vietnamese species and a key to the Oriental species of Pareumenes (Nortonia) de Saussure, 1855 (Hymenoptera: Vespidae: Eumeninae), Raffles Bulletin of Zoology 68, pp. 588-594 : 592-593

Key to species of the genus Pareumenes occurring in

Oriental region

The characters are applicable to both sexes unless the sex is specified. The characters are taken from the description of the species following Liu (1941), van der Vecht (1963), Kim (2014), and Selis (2016).

1. Parastigma of forewing shorter or slightly longer than stigma, metasomal petiole shorter and wider........................................ ..........................................2 (subgenus Nortonia de Saussure )

– Parastigma of forewing much longer than stigma (slightly greater than 1.5 times as long as stigma), metasomal petiole longer and narrower ... 3 (subgenus Pareumenes de Saussure )

2. Clypeus with coarse punctures, border between punctures raised to form longitudinal reticulation, in frontal view as wide as high; lateral side of propodeum deeply emarginate at apex. Clypeus entirely yellow; tergum II with a broad apical yellow band ............................................... P. taiwanus ( Sonan, 1937)

– Clypeus with sparse and strong punctures, border between punctures smooth, in frontal view 1.1 times as wide as high; lateral side of propodeum shallowly emarginate at apex. Clypeus black with irregular yellow mark in the middle; tergum II entirely black.................................. P. caoduong , new species

3. Dorsal face of propodeum with coarse punctures (except in P. obtusus with sparser and shallower punctures); tergum III with raised apical lamella, the lamella narrowed laterally; apical teeth of propodeum short, approximately rectangular or round, separated from the valvulae by a semi-circular emargination. .................................................................................................4

– Dorsal face of propodeum with sparse and strong punctures; tergum III with slightly raised apical lamella, evanescent at lateral sides, or without raised apical lamella; apical teeth of propodeum very sharp and long, separated from the valvulae by a very deep emargination, much greater than a semi-circular. .................................................................................................6

4. Vertex with a few distinct punctures near the top of the eyes; prescutal furrow extending about one-fourth the length of the mesoscutum; lateral face of propodeum largely smooth, with very few coarse punctures ...................... P. obtusus Liu, 1941

– Vertex with coarse and dense punctures near the top of the eyes; prescutal furrow extending about one-fifth the length of the mesoscutum; lateral face of propodeum with coarse striae.........................................................................................5

5. Male with last antennal segment in recurved position reaching the apex of the tenth segment; clypeus with apical margin wide (slightly greater than one-third of the maximum width of clypeus); propodeum with apical teeth short, approximately rectangular ............................ P. bengalensis ( Fabricius, 1804)

– Male with last antennal segment in recurved position not quite reaching the apex of the tenth segment; clypeus with apical margin narrower (one-fourth of the maximum width of clypeus); propodeum with apical teeth sharper, forming an angle of about 60 ° ................................. P. brevirostratus ( de Saussure, 1855)

6. Sternum II strongly swollen at about one-third of the sternum from base.................................................................................7

– Sternum II gradually convex from base to apical margin .....8

7. Vertex and gena strongly developed; postocellar area raised; semicircular impression on vertex present; mesosoma smooth and shiny, without punctures; tergum I with proportion between long and maximum width shorter and less curved laterally; sternum I with strong transverse striations; tergum II weakly reflexed apically; basal convexity of sternum II bearing a central hump .............................................. P. impunctatus Selis, 2016

– Vertex and gena normally developed; postocellar area flattened; vertex without semicircular impression; mesosoma with deep well impressed punctures; tergum I longer and strongly curved in lateral view; sternum I with fine and weak striations; tergum II strongly reflexed apically; basal convexity of sternum II normally rounded ............. P. nigerrimus van der Vecht, 1963

8. Punctures on head, mesoscutum, and mesepisternum very coarse; metanotum with distinct punctures; mesosoma covered with dense black pubescence. Body entirely black, with small yellow spots between antennae and antennal scape; wings yellowish.......................................... P. pullatus ( Smith, 1864)