In this taxonomical study, one new genus and 41 new species of the subfamily Mesochorinae (Hymenoptera, Ichneumonidae) are described from Southeast Asia, namely from Indonesia, Malaysia, Thailand and Vietnam. The new genus is Orientochorus n. gen., the new species are Orientochorus tonkinensis n. sp., Astiphromma bicoloratus n. sp., Mesochorus achterbergi n. sp., Mesochorus anamnesis n. sp., Mesochorus brevipunctatus n. sp., Mesochorus cariniscuta n. sp., Mesochorus controversus n. sp., Mesochorus diversidens n. sp., Mesochorus flavator n. sp., Mesochorus flavopronotalis n. sp., Mesochorus fuscomaculatus n. sp., Mesochorus halmaherae n. sp., Mesochorus harlequinus n. sp., Mesochorus kinabaluensis n. sp., Mesochorus lamdongensis n. sp., Mesochorus longimurus n. sp., Mesochorus longistylus n. sp., Mesochorus longivalvator n. sp., Mesochorus malaysiacus n. sp., Mesochorus malucutus n. sp., Mesochorus nigripleuris n. sp., Mesochorus nigrofemur n. sp., Mesochorus nigromaculatus n. sp., Mesochorus paratenebris n. sp., Mesochorus pictiloides n. sp., Mesochorus pterostigmator n. sp., Mesochoprus rufator n. sp., Mesochorus sabahensis n. sp., Mesochorus sapaensis n. sp., Mesochorus semifuscus n. sp., Mesochorus semipunctatus n. sp., Mesochorus siamensis n. sp., Mesochorus stigmaticolor n. sp., Mesochorus striatofacies n. sp., Mesochorus sulaensis n. sp., Mesochorus sumaterae n. sp., Mesochorus templator n. sp., Mesochorus tenebris n. sp., Mesochorus tonkinensis n. sp., Mesochorus train n. sp., and Mesochorus vietnamensis n. sp. All species are illustrated and described in detail. In addition, a key for the females of the known Mesochorus species of Southeast Asia is presented.
In this study, new distributional records are given for 98 species and subspecies of Darwin wasps of the subfamily Ichneumoninae (Hymenoptera, Ichneumonidae) from Maritime Southeast Asia, namely from Indonesia and Malaysia: Sabah. Four genera, 31 species and three subspecies are described as new. The new genera are: Atanyjoppoides n. gen., Moluccarches n. gen., Orientodromus n. gen. and Platylaboides n. gen. The new species are: Achaius sabahensis n. sp., Allonotus rufiventris n. sp., Amblyjoppa nigra n. sp., Amblyjoppa striata n. sp., Atanyjoppoides mandibulator n. sp., Benyllus mesonotator n. sp., Benyllus rufostriatus n. sp., Benyllus sundaensis n. sp., Celebarches albifrons n. sp., Celebarches nigritor n. sp., Celebarches sabahensis n. sp., Celebarches tricolor n. sp., Coelichneumon (Exephanides) nigropropodealis n. sp., Compsophorus (Xenojoppa) quadrimaculatus n. sp., Deniya scutellaris n. sp., Eccoptosage nigrifemur n. sp., Eccoptosage sabahensis n. sp., Heresiarches simile n. sp., Lareiga nigrita n. sp., Lissosculpta albifrons n. sp., Lissosculpta malucuensis n. sp., Lissosculpta seramensis n. sp., Losgna baliensis n. sp., Losgna rufobasalis n. sp., Moluccarches albimaculatus n. sp., Orientodromus thyridialis n. sp., Platylaboides javanicus n. sp., Pseudoplatylabus rufoniger n. sp., Setanta albimaculata n. sp., Stirexephanes albicoxis n. sp., and Stirexephanes rufopetiolaris n. sp. The new subspecies are: Allonotus rufus sumatrensis n. ssp., Amblyjoppa rufobalteata sumatera n. ssp., and Anisobas vietnamensis sabahensis n. ssp. Vulgichneumon stegemanni (Heinrich, 1934) is transferred to the genus Virgichneumon Heinrich, 1977, n. stat.. For the following species the hitherto unknown are described: Barichneumonites properans (Tosquinet, 1903), Celebarches unicus Heinrich, 1934, Celebichneumon egregius Heinrich, 1934, Coelichneumon (Coelichneumon) lineiscutis Heinrich, 1966, Eccoptosage quadridentata (Cameron, 1905), Menkokia major (Heinrich, 1934), Nesostenodontus formosanus Cushman, 1937, Stenichneumonopsis albifasciatus Heinrich, 1934, Stirexephanes impictus Heinrich, 1934, Ulesta plagiata Heinrich, 1934, and Virgichneumon stegemanni (Heinrich, 1934). All new species are described in detail and illustrated. For the known species of Celebarches Heinrich, a determination key is provided.