Contribution to the taxonomy of the Southeast Asian Mesochorinae (Hymenoptera, Ichneumonidae) Author Riedel, Matthias text Zootaxa 2023 2023-02-24 5245 1 1 72 http://dx.doi.org/10.11646/zootaxa.5245.1.1 journal article 56507 10.11646/zootaxa.5245.1.1 624e6dc0-0ac9-4891-b050-c9f3e95cfe19 1175-5326 7673309 7015E475-56A7-4AF1-8964-A167C672A234 Mesochorus (Mesochorus) flavopronotalis nov. sp. ( Figs 2D , 9C , 14C , 16C, 22H) Holotype . ( ♀ ) NW Vietnam : Tonkin, Hoang Lien N. R . 10 km SW Sa Pa , c. 1550 m , 22–29.x.1999 , Malaise traps , C. v. Achterberg , RMNH´99 (Leiden). Paratype . (♁) similar label (Leiden). Etymology. The species name refers to the yellowish pronotum. Description. ♀ : Body length 4.9 mm . Length of fore wing 4.2 mm . Head . Flagellum with> 26 flagellomeres (tips broken off); 1 st flagellomere 6.7 × longer than wide and 1.6 × longer than 2 nd flagellomere, 0.7 × as long as eye; 2 nd flagellomere 4.1 × longer than wide. Temple short, strongly and roundly narrowed behind eye, dorsally 0.4 × as long as eye. OED 1.7 × and OOD 0.7 × ocellar diameter. Occipital carina complete medially. Frons smooth, with sparse coarse punctures laterally. Face ( Fig. 9C ) densely punctate medially but with sparse punctures on facial orbit, with median ridge, width 1.1 × combined length of face and clypeus and 1.0 × eye length; inner eye margins slightly divergent. Subantennal transverse carina strong, dipped medially. Malar space, mandible and ventral 0.5 of facial orbit widely striate. Malar space 1.0 × as long as width of mandibular base. Mandible with two teeth, ventral tooth slightly larger than dorsal tooth. Genal carina reaching hypostomal carina away from mandibular base, both carinae low. Mesosoma . 1.6 × longer than high. Mesoscutum ( Fig. 14C ) densely punctate, with rather dense punctures postero-medially. Scuto-scutellar groove smooth. Scutellum moderately convex, with fine sparse punctures, without lateral carina, not pointed apically. Mesopleuron ( Fig. 16C ) with rather dense punctures fronto-dorsally, with very sparse fine punctures ventrally. Dorsal end of epicnemial carina separated from frontal margin of mesopleuron. Metapleuron with sparse punctures. Submetapleural carina low. Propodeum completely carinate. Area basalis triangular, 1.5 × longer than wide. Area superomedia 1.7 × longer than wide and 0.8 × as long as area petiolaris; anterior transverse carina (costula) reaching at its middle. Area petiolaris 1.5 × longer than wide. Hind femur 4.5 × longer than wide; hind metatarsus 0.6 × as long as hind tibia and 2.8 × longer than 2 nd hind tarsomere; hind claw with two long basal teeth, basal tooth longer than apical one. Areolet pointed frontally; vein 2m-cu slightly proximad its middle. Vein 1cu-a postfurcal by 0.3 × its length. Postnervulus intercepted basad its middle. Pterostigma 3.3 × longer than wide. Hind wing with 4 distal hamuli. Nervellus of hind wing vertical. Metasoma. 1 st tergite 2.6 × longer than wide. Postpetiolus smooth with few short rugae. 2 nd tergite 1.2 × wider than long. Thyridium transverse-oval. Ovipositor sheath ( Fig. 22H ) with sparse setae in apical 2/3, 7.9 × longer than wide, 0.5 × as long as hind tibia and 1.0 × as long as hind metatarsus, moderately narrowed in apical 0.4. Color. Antenna brown. Head reddish-yellow; face in dorsal third and clypeus brownish. Palps, mandible except teeth, malar space, ventral gena, wide facial orbit and ventral third of frontal orbit cream-yellow; frons medially and stemmaticum black; occiput dorsally brown. Mesoscutum black, with two paramedian reddish-brown stripes. Scutellum black, reddish laterally and apically. Propodeum reddish-yellow; area basalis, area externa and area dentipara black. Propleuron and pronotum yellowish; mesopleuron brown, with some two reddish spots; metapleuron brown. 1 st tergite black, its sternite reddish. 2 nd tergite black, with oval yellowish spot in apical 0.5. 3 rd tergite black, with oval yellow spot in basal 0.4. 4 th and 5 th tergites yellowish, with basal and apical brown bands; following tergites brownish. 3 rd to 6 th sternites brownish laterally. Ovipositor sheath brown. Fore and mid legs cream-yellow. Hind coxa yellow, brownish dorsally; hind femur reddish, with internal and external brown stripes; hind tibia creamyellow, black in basal 0.2 and apical 0.3; hind tarsus brownish. Pterostigma brown. ♁: Body length 4.2 mm . Length of fore wing 4.2 mm . Head. Flagellum with 31 flagellomeres; 1 st flagellomere 7.9 × longer than wide and 1.6 × longer than 2 nd flagellomere, 0.8 × as long as eye; 2 nd flagellomere 4.9 × longer than wide; preapical flagellomere 2.5 × longer than wide. Temple rather short, strongly and roundly narrowed behind eye, dorsally 0.4 × as long as eye. OED 1.6 × and OOD 0.7 × ocellar diameter. Face width 1.0 × combined length of face and clypeus and 0.9 × eye length; inner eye margins slightly divergent. Malar space, mandible and ventral 0.4 of facial orbit widely striate. Mandible with two equal teeth. Mesosoma . 1.6 × longer than high. Mesopleuron with dense punctures fronto-dorsally, ventral part with dense punctures frontally and very sparse punctures posteriorly. Propodeum carinate as in ♀ . Hind femur 4.9 × longer than wide; hind metatarsus 0.6 × as long as hind tibia; hind claw with one short basal tooth. Areolet shortly sessile frontally; vein 2m-cu slightly proximad its middle. Vein 1cu-a postfurcal by 0.3 × its length. Pterostigma 2.8 × longer than wide. Hind wing with 4 distal hamuli. Metasoma. 1 st tergite 2.7 × longer than wide. Postpetiolus smooth with few short rugae. 2 nd tergite 1.0 × as long as wide. Thyridium transverse-oval. Paramere 1.1 × longer than hind metatarsus, slightly bent upwards and slightly clubbed apically. Color. As in ♀ except: Face and clypeus reddish-yellow, face with two small paramedian brownish spots dorsally. Mesoscutum blackish, with two paramedian reddish-yellow stripes. Mesopleuron reddish-yellow, with three brownish spots. Propodeum black in basal 2/3, reddish-yellow in apical third. 2 nd tergite black, with triangular yellow spot in apical 0.5 and with narrow yellow hind margin. 3 rd tergite black, with triangular spot in basal 0.7. Paramere brownish. Hind tarsus except mainly yellowish; metatarsus ochreous. Taxonomical remark. With its sessile areolet, postfurcal vein 1cu-a, stick-shaped ovipositor and short area superomedia, this species belongs to the dispar group sensu Schwenke (1999) . It is characterized by the dorsally brownish face, dark hind femur and largely infuscate hind tibia, and the typical color pattern of meso- and metasoma.