Anterhynchium conformalum, Dang & Tran & Nguyen & Nguyen, 2025

Key to species of the genus Anterhynchium View in CoL View at ENA from the Oriental region

For the key to the species of the subgenus Anterhynchium ( A. abdominale , A. mellyi , A. punctatum ) see Nguyen (2015).

Below is the key to 12 species of the subgenus Dirhynchium van der Vecht, 1963 . The diagnostic characters were taken from the descriptions and figures provided by van der Vecht (1963), Giordani Soika (1973), Kumar (2013), and Yamane & Murota (2015), with additional reference to specimens of A. conformalum sp. nov. and A. flavolineatum from Vietnam, and A. gibbifrons from China.

1. Terga I–II smooth or almost smooth with some small punctures laterally or with small, dense punctures................. 2

- Terga I–II not smooth with large and dense punctures......................................................... 4

2. Female clypeus smooth; terga I–II entirely smooth; head and mesosoma with short and moderately full brown and whitish pubescence. Terga I–II with yellow apical band; fore wing strongly diffusely brown, hind wings almost hyaline..................................................................................... A. basimacula ( Cameron, 1897) View in CoL

- Female clypeus with dense punctures; terga I–II almost smooth with some small punctures laterally or with small, dense punctures; head and mesosoma with black pubescence. All terga black; wings different.............................. 3

3. Terga I–II smooth and shiny with fine and sparse punctures, preapical margin of T2 with bigger and dense punctures; T3 entirely coarsely punctate; mesoscutum with large and shallow flatbottomed punctures; metasoma without pubescence; head and mesosoma with black and sparse pubescence; dorsal carinae of propodeum developed in a triangular tooth behind metanotum. Body entirely black with pale yellow markings on scape, interantennal area; legs entirely black with pale yellow markingson apical segment of fore tarsus; wings strongly fuscous with strong purplish effulgence...................................................................................................... A. astrophilum Giordani Soika, 1996 View in CoL

- All terga entirely covered in small and dense punctures; mesoscutum with small and deep punctures; whole body covered with dense black pubescence; dorsal carinae of propodeum not evident. Body black with reddish-orange scape and yellow spot between antennal insertions; legs more or less reddish-brown; wings orange with black basal half................................................................................................. A. townesi van der Vecht, 1963

4. Mesoscutum with very dense punctures near apical margin, interspaces between punctures tending to run into irregular longitudinal striae..................................................................................... 5

- Mesoscutum with sparse punctures near apical margin, with several interspaces at least as large as the puncture diameter.. 10

5. Frontal area surrounded by eyes, ocelli and antennal insertions distinctly raised; cephalic foveal depression large, with anterior margin deeply emarginate, posterior margin very close to occipital margin.......... A. gibbifrons Yamane & Murota, 2015

- Frontal area surrounded by eyes, ocelli and antennal insertions weakly raised; cephalic foveal depression large, with anterior margin slightly emarginate, posterior margin further to occipital margin than above................................. 6

6. Female clypeus with apical margin deeply emarginate medially, forming a sharp tooth on each lateral side; the excavation semicircle, about 2 × as wide as high; anterior pronotal yellow/orange band developed and not interrupted medially.............................................................................. A. inamurai Yamane & Murota, 2015 View in CoL

- Female clypeus with apical margin shallowly emarginate medially, forming a blunt tooth on each lateral side; the excavation slightly concave; if present, anterior pronotal yellow/orange band less developed and interrupted medially............... 7

7. Female clypeus in frontal view wider than long, nearly 1.1× as wide as long; apical margin deeper emarginate medially, forming a sharper tooth on each lateral side, width of the emargination about 1/3 width of clypeus between inner eye margins; metasoma with larger punctures. Metasoma black with extensive yellow marks, terga I-II with very thick yellow apical band. Wings brown.................................................................... A. flavopunctatum ( Smith, 1852) View in CoL

- Female clypeus in frontal view longer than wide, about 1.1 × as long as wide; apical margin shallower emarginate medially, forming a blunter triagle tooth on each lateral side, width of the emargination about 1/4 width of clypeus between inner eye margins; metasoma with smaller punctures. Metasoma entirely black or black with less yellow marks (terga I-II with much thinner yellow apical band or the yellow band absent). Wings very dark, with strong violet reflections.................. 8

8. Clypeus and mesosoma with dense and finer punctures, which a particular velvety appearance; metasoma also appearing velvety; terga III–IV with dense punctures same as on the tergum II................ A. yunnanensis Giordani Soika, 1973

- Clypeus and mesosoma with dense and stronger punctures, not velvety appearance; metasoma also appearing not velvety; terga III– IV with dense punctures same as on the tergum II, but very coarse and large at apical margin...................... 9

9. Male digitus with swollen round apex. Terga I–II usually entirely black, sometimes with a narrow yellow band at apical margin laterally.......................................................................... A. conformalum sp. nov.

- Male digitus with tapered apex. Terga I–II with thick yellow apical bands.............. A. flavomarginatum ( Smith, 1852) View in CoL

10. Anterior margin of clypeus deeply emarginate, the depth of the incision about one third of its width, the apical teeth sharp; basal half of scutellum sparsely punctate, the interspaces generally larger than the punctures, the median groove absent or only very faintly indicated; punctuation of the metasoma somewhat fine and superficial. Body extensively marked with yellow; eye emarginations black......................................................... A. hamatum van der Vecht, 1963 View in CoL

- Anterior margin of clypeus very shallowly emarginate, the apical teeth bluntly rounded; basal half of scutellum rather densely punctate, except near the distinct median groove, the interspaces rarely larger than the punctures; punctuation of the metasomal segments stronger and deeper. Body less marked with yellow; eye emarginations yellow............................ 11

11. Temple with strong punctures; lower metapleuron with rugose punctures; declivity of propodeum bordered dorsally by a somewhat strong, irregular carina; posterior surface of propodeum with coarsely striations. Metasoma black...................................................................................... A. coracinum van der Vecht, 1963 View in CoL

- Temple with weaker punctures; lower metapleuron almost smooth with very fine punctures; declivity of propodeum without carina dorsally; posterior surface of propodeum with weaker striations. Metasoma black with yellow apical margin on each tergum...................................................................... A. flavolineatum ( Smith, 1857) View in CoL