taxonID	type	description	language	source
03AC87C4FFF3FFF957B9FDA3FCBA06E7.taxon	description	Lectotype: (³) “ bilineatus ” (Lund), type not examined. syn. nov. Stictopisthus sacromontis SCHWENKE, 1999: 30. H o l o t y p e: (♀) “ Italia-Piemonte AL Sacro Monte di Crea, T. M. 29. VII. 1986 Scaramozzino P. L. leg. ” (ZSM), type examined. D e s c r i p t i o n: ♀. Body length 2.5 - 4.0 mm. Flagellum with 20 - 24 segments; 1 st flagellar segment 3.2 - 3.6 × as long as wide and 0.4 - 0.5 × as long as eye; 2 nd segment 2.3 - 2.8 × and preapical segment c. 2 × as long as wide. Temple moderately narrowed behind eye, dorsally 0.7 × as long as eye. OED 1.4 - 1.8 × and OOD 1.6 × ocellar diameter. Occipital carina complete medially. Frons with very fine transverse granulation. Face coarsely punctate, with ± distinct transverse striation, its width 1.2 - 1.3 × combined length of face and clypeus and 1.0 - 1.1 × eye length, lateral margins convergent ventrally. Mandible with two equally sized teeth. MI 0.7 - 0.8. Mesosoma moderately depressed, 1.9 - 2.0 × as long as high. Mesoscutum densely punctate, shining. Mesopleuron and metapleuron densely and coarsely punctate. Scuto-scutellar groove smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia 2.0 × as long as wide; costula reaching at its middle. Area petiolaris hexagonal, slightly as long as wide. Hind femur 3.0 - 3.1 × as long as wide. Inner apical spur of hind tibia 0.62 × as long as hind metatarsus. Hind claws without visible teeth. Areolet sessile frontally; vein 2 m-cu reaching ± proximad its middle. Vein 1 cu-a strongly postfurcal by 0.5 - 0.8 × its length. Postnervulus intercepted in its middle. Pterostigma 3.1 × as long as wide. Anterior margin of radial cell 0.9 × as long as pterostigma; distal part of metacarpus very short or entirely absent. Hind wing with 4 distal hamuli. 1 st tergite 2.1 - 2.4 × as long as wide; postpetiole ± strongly aciculate. 2 nd tergite 0.7 - 0.9 × as long as wide. Ovipositor sheath 6.0 - 7.1 × as long as wide and 0.9 - 1.0 × as long as hind metatarsus, slightly narrowed in apical 0.2, with long setae. Color: black. Clypeus, face, frons, gena, temple, tegula and subtegular ridge yellow; stemmaticum and occiput, and sometimes frons medially brown to black. Flagellum yellow, fuscous apically. Mesosoma black; pronotum brownish, with wide yellowish margins; mesoscutum with yellow stripes laterally and sub-medially, confluent frontally. Scutellum yellowish or reddish, with baso-central fuscous spot. 1 st tergite black, often with yellowish spot or band apically; 2 nd tergite black, yellow in the apical 0.3 - 0.4; 3 rd tergite brown, yellowish in the basal 0.5 - 0.7; following tergites brown with narrow yellowish apical margins. Ovipositor sheath black. Pterostigma hyaline to ochreous. Legs yellowish; hind coxa reddish or brownish; hind femur sometimes with diffuse brownish suffusion; hind tibia narrowly black at base and narrowly infuscate apically; hind metatarsus narrowly brown at apex. ³. Body length 3.5 - 4.0 mm. Flagellum with 21 - 24 segments; 1 st flagellar segment 3.9 × and 2 nd segment 2.9 × as long as wide. OED 1.3 - 1.5 × and OOD 1.5 - 1.7 × ocellar diameter. Face width 1.2 × combined length of clypeus and face and 1.0 - 1.1 × eye length. Mesosoma 1.7 - 1.9 × as long as high. Mesopleuron densely punctate. Hind femur 3.7 - 3.8 × as long as wide. Vein 1 cu-a strongly postfurcal by 0.5 - 1.0 × its length. Area basalis and area superomedia confluent; costula weak. Area petiolaris wider than long. 1 st tergite 2.3 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite 0.8 - 0.9 × as long as wide. Stylet 1.1 - 1.5 × as long as 2 nd hind tarsomere, distinctly clubbed apically. Color: Pronotum yellow-red, blackish laterally. Mesopleuron sometimes reddish-brown. Hind tibia narrow at base and apex brownish. Hind tarsus ± brownish. Color otherwise as in ♀. D i s t r i b u t i o n: Transpalaearctic; examined material from Bulgaria *, France, Italy, Kazakhstan *, Mongolia *, Russia * (Volgograd district), Turkey *.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFF0FFF857B9FCD6FC750589.taxon	description	H o l o t y p e: (♀) “ Italia, Piemonte La Cassa (Torino) VIII 82, Scaramozzino legit ” (ZSM), type examined. A d d i t i o n a l m a t e r i a l: France: Dordogne, Ste. Alvère, Malaise trap, 1 ♀ 26. ix. - 5. x. 1994, leg. R. R. Askew (EDI). D e s c r i p t i o n: ♀. Body length 2.0 - 2.3 mm. Flagellum with 24 - 25 segments; 1 st flagellar segment 5.7 × as long as wide and 0.60 - 0.63 × as long as eye; 2 nd segment 4.6 × and preapical segment c. 2 × as long as wide. Temple moderately narrowed behind eye, dorsally 0.7 × as long as eye. OED 1.6 - 1.7 × and OOD 1.2 × ocellar diameter. Frons finely and transversely aciculate laterally. Face coarsely punctate, its width 1.0 - 1.1 × combined length of face and clypeus and eye length. Ventral third of facial orbit with some oblique striae. Mandible with two equally sized teeth. MI 0.6. Mesosoma not depressed, 1.7 - 1.8 × as long as high. Mesopleuron with coarse but sparse punctures ventrally. Scuto-scutellar groove rather wide, smooth. Propodeum completely carinate, area basalis and area superomedia confluent. Hind femur 3.5 - 4.3 × as long as wide. Inner apical spur of hind tibia 0.63 × as long as hind metatarsus. Hind claws with 2 visible teeth basally. Areolet sessile frontally; vein 2 m-cu reaching slightly distad its middle. Vein 1 cu-a strongly postfurcal by slightly more than its length; postnervulus intercepted slightly proximad its middle. Distal part of metacarpus about as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus slightly reclivous. 1 st tergite 2.6 × as long as wide. 2 nd tergite 0.9 - 1.0 × as long as wide. Ovipositor sheath 7.7 × as long as wide and about as long as hind metatarsus, strongly narrowed and almost pointed apically, slightly bent upwards apically. Color: black. Head yellowish or reddish; face, stemmaticum and occiput brownish. Mesosoma blackish; pronotum and fronto-dorsal third of mesopleuron yellowish or brownish; mesopleuron otherwise dark brown. 1 st tergite black, yellow basally; 2 nd tergite black, yellow in apical 0.4; following tergites brownish. Legs yellowish-red; hind coxa reddish or brown; hind tibia yellow, narrowly fuscous at apex (0.5 - 1.0 × its width). Pterostigma hyaline. Ô unknown. D i s t r i b u t i o n: Europe; examined material from Italy and France *.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFF1FFF857B9FE43FD760142.taxon	description	H o l o t y p e: (♀) “ 34.12, Türkei [Turkey], Cukorova Citrus - Plant. ” (ZSM), type examined. D e s c r i p t i o n: ♀. Body length 2.8 - 3.5 mm. Tips of flagella broken off; 1 st flagellar segment 3.8 - 4.0 × as long as wide and 0.50 - 0.56 × as long as eye; 2 nd segment 3.5 × as long as wide. Temple moderately and roundly narrowed behind eye, dorsally 0.7 × as long as eye. OED 1.6 - 1.8 × ocellar diameter. Face coarsely and densely punctate, its width 1.2 - 1.3 × combined length of face and clypeus and 1.1 - 1.2 × eye length, sides slightly convergent ventrally. MI 0.6 - 0.7, finely striate. Mesosoma moderately depressed, 2.0 - 2.2 × as long as high. Mesoscutum densely punctate, shining. Mesopleuron densely or rather densely and coarsely punctate. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia short; costula reaching at its middle. Area petiolaris hexagonal, about as long as wide. Hind femur 2.9 - 3.2 × as long as wide. Areolet shortly sessile frontally. Vein 1 cu-a strongly postfurcal by about its length. Pterostigma 2.9 × as long as wide. Distal part of metacarpus 0.7 - 0.9 × as long as width of pterostigma. 1 st tergite 2.3 - 2.5 × as long as wide, postpetiole striate. 2 nd tergite 0.8 - 0.9 × as long as wide. Ovipositor sheath slender, 6.9 - 7.2 × as long as wide and 1.0 - 1.1 × as long as hind metatarsus, almost bare and strongly narrowed in apical half. Color: black. Head yellowish; face and occiput brownish. Basal flagellomeres yellowish. Mesosoma brownish; sometimes pronotum reddish and mesoscutum with H-shaped central red spot. Propodeum in basal 2 / 3 blackish. 1 st tergite dark brown, basally and apically yellowish; 2 nd tergite yellow, with brownish fronto-lateral spots; 3 rd tergite yellowish at base and brownish in apical third; following tergites brownish and slightly vespoid. Ovipositor sheath black. Legs brownish-yellow; hind coxa and hind femur with ± fuscous suffusion; hind tibia yellow, fuscous in apical 0.15 - 0.2 (0.7 - 1.0 × tibial width). Pterostigma hyaline. Ô unknown. D i s t r i b u t i o n: Only known from Turkey.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFF1FFF657B9FA7BFC9806A5.taxon	description	syn. Mesochorus pungens SCHWENKE, 1999: 58, synonymized by RIEDEL (2018). H o l o t y p e: (Ô) “ Dessau-Anh. 117 / 88 4.7. leg. Zoerner ” (SDEI, Müncheberg), type examined. syn. nov. Stictopisthus hispanicus SCHWENKE, 1999: 32, Ô. H o l o t y p e: (³) “ El Soldado, Sierra Morena, 26.7.26, Seyrig ” (Paris), photos of type [MNH Paris] studied. D e s c r i p t i o n: ♀. Body length 3.0 - 3.5 mm. Flagellum with 24 - 26 segments; 1 st flagellar segment 3.7 - 4.3 × as long as wide and 0.50 × as long as eye; 2 nd segment 3.0 × and preapical segment 1.5 - 1.7 × as long as wide. Temple moderately and roundly narrowed behind eye, dorsally 0.6 - 0.7 × as long as eye. OED 1.4 - 1.8 × ocellar diameter. Frons and occiput with sparse punctures. Face coarsely punctate, its width 1.3 - 1.4 × combined length of face and clypeus and 1.1 - 1.2 × eye length, with ± parallel sides. Mandible with two equally sized teeth, sometimes upper tooth slightly larger. MI 0.4 - 0.6. Mesosoma strongly depressed, 2.2 - 2.3 × as long as high. Mesopleuron with coarse but sparse punctures ventrally, shining. Metapleuron with slightly denser punctures, shining. Pronotum almost smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area petiolaris wider than long. Hind femur 2.9 - 3.1 × as long as wide. Areolet sessile or pointed frontally. Vein 1 cu-a strongly postfurcal by 0.7 - 1.0 × its length. Pterostigma 2.8 × as long as wide. Apical part of metacarpus long, about as long as width of pterostigma. 1 st tergite 2.3 - 2.7 × as long as wide; postpetiole coarsely striate or aciculate. 2 nd tergite 0.9 × as long as wide. Thyridium comma-shaped, transverse. Ovipositor sheath densely pilose, stout, 5.6 - 6.2 × as long as wide and about as long as hind metatarsus, slightly narrowed apically. Color: black. Head reddish-yellow; occiput brownish. Two to three basal flagellomeres yellow, flagellum otherwise ochreous. Pronotum and mesopleuron reddish; mesoscutum brownish, with H-shaped central reddish mark or reddish with brownish lateral stripes and fronto-medial spot; scutellum, propodeum and metapleuron blackish. 1 st tergite black, sometimes 1 st sternite dark reddish. 2 nd tergite yellow, basolateral with dark brown medially confluent stripes; 3 rd tergite yellow, brownish laterally; following tergites yellowish-brown basally and yellowish apically. Legs reddish-yellow; hind tibia pale yellow, at narrow base and apical 0.1 - 0.2 (0.5 - 1.0 × tibial width) ± brownish. Pterostigma hyaline or pale ochreous, with slightly darker margins. ³. Body length 3.5 - 4.5 mm. Flagellum with 27 - 29 segments; 1 st flagellar segment 5.9 - 6.0 × as long as wide and 0.60 - 0.63 × as long as eye; 2 nd segment 4.1 × and preapical segment 2.2 × as long as wide. Temple moderately narrowed behind eye, dorsally 0.7 - 0.8 × as long as eye. OED 1.4 - 1.8 × and OOD 0.9 × ocellar diameter. Occipital carina complete medially. Width of face 1.1 - 1.2 × combined length of face and clypeus and 1.0 - 1.1 × eye length, with parallel sides. Mandible with two equal teeth. Mesosoma slightly or moderately depressed, 1.8 - 2.1 × as long as high. Mesoscutum densely punctate. Mesopleuron with rather dense to dense punctures. Scuto-scutellar groove smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Hind femur 3.5 - 4.2 × as long as wide. Areolet pointed to sessile frontally; vein 1 cu-a strongly postfurcal by 0.5 - 0.8 × its length. Pterostigma wide, 2.3 - 2.5 × as long as wide. Distal part of metacarpus long, length 1.0 × width of pterostigma. 1 st tergite 2.6 - 2.8 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite 0.9 - 1.0 × as long as wide. Thyridium comma-shaped, at base of tergite. Stylet long, stick-shaped or slightly clubbed apically, 1.4 - 1.8 × as long as 2 nd hind tarsomere. Color: Head yellow. Palps, gena, mandible (except teeth), face, frontal margin and hind edge of pronotum, tegula, wing base, and fore and mid coxae and trochanters cream-yellow. Flagellum yellow basally, ± infuscate distally. Mesosoma reddish-yellow; mesoscutum with two brownish to blackish lateral stripes and blackish fronto-median spot; propodeum black in frontal 1 / 2 - 2 / 3. 1 st sternite dark reddish; 1 st tergite black, sometimes reddish basally; 2 nd tergite black, with triangular or arched yellow spot in apical ½; 3 rd tergite brown, with tongue-shaped yellow spot in basal 2 / 3; following tergites brown or vespoid. Legs yellow, hind femur with brownish suffusion apically, hind tibia cream-yellow, brownish in apical 0.15 - 0.2 (1.0 - 1.5 × tibial width); hind tarsomeres yellowish, with ± brown tips. Pterostigma brown, pale yellow proximally and sometimes distally. R e m a r k s: The correlation of sexes was confused by SCHWENKE (1999) who described the stylets (e. g. parameres) of ³ as apically pointed, but the parameres are stick-shaped and slightly clubbed apically (see photos of HT from Mus. Nat. Hist. Naturelle / Paris). It should be noted here that all known European ³³ with apically pointed parameres belong to Mesochorus unicinctor (THUNBERG). D i s t r i b u t i o n: West Palaearctic; examined material from Belgium *, Bulgaria, Corsica *, Czech Republic (Moravia) *, Germany, Greece *, Poland *.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFFFFF557B9FD18FDC201AA.taxon	description	Lectotype: (♀) [Great Britain] (Norwich), type not examined. syn. Mesochorus convexicollis THOMSON, 1886: 344, ♀ ³. Lectotype: (♀) “ Hbg., convexicollis ” (LUND), synonymized by MEYER (1935), type not examined. syn. Mesochorus turbidus SCHWENKE, 1999: 39, synonymized by RIEDEL (2019). H o l o t y p e: (♀) “ I, BZ, Villanders 1000 m, 21.9.1978, E. Haeselbarth ” (ZSM), type examined. syn. nov. Stictopisthus polonius SCHWENKE, 1999: 32, ³. H o l o t y p e: (³) “ 399 ” (ZSM), type examined. D e s c r i p t i o n: ♀. Body length 2.0 - 3.0 mm. Flagellum with 20 - 24 segments; 1 st flagellar segment 6.5 - 7.0 × as long as wide and 0.62 - 0.65 × as long as eye; 2 nd segment 4.5 - 5.0 × and preapical segment 1.7 - 2.0 × as long as wide. Temple parallel or slightly widened behind eye, moderately narrowed apically, dorsally 0.8 × as long as eye. OED 1.8 × ocellar diameter. Occipital carina sometimes weak medially. Face coarsely punctate, its width 1.1 - 1.2 × combined length of face and clypeus and 1.0 - 1.1 × eye length, sides parallel. Malar space and ventral 0.3 of facial orbit finely striate. Dorsal mandibular tooth often slightly larger than ventral tooth. MI 0.3 - 0.4. Mesosoma moderately depressed, 1.8 - 2.0 × as long as wide. Mesoscutum densely punctate. Mesopleuron with sparse punctures or almost smooth ventrally. Scuto-scutellar groove smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia 2 × as long as wide; costula carina reaching at its middle. Area petiolaris hexagonal, as long as wide. Hind femur 3.5 - 3.6 × as long as wide. Areolet pointed frontally; vein 2 m-cu reaching at its middle. Vein 1 cu-a moderately postfurcal by 0.4 - 0.6 × its length. Pterostigma c. 3.3 × as long as wide. Apical part of metacarpus long, about as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus vertical. 1 st tergite 2.8 - 3.1 × as long as wide; postpetiole aciculate. 2 nd tergite 0.9 - 1.0 × as long as wide. Thyridium comma-shaped. Ovipositor sheath 5.5 - 6.6 × as long as wide and 0.8 - 0.9 × as long as hind metatarsus, not distinctly narrowed apically, slightly bent upwards. Color: black. Palps and tegula yellow. Flagellum yellowish proximally, ± infuscate distally. Face brownish; stemmaticum and occiput black. Mandible, gena, clypeus apically and orbits ± yellowish-red. Mesosoma black; mesoscutum sometimes with H-shaped dark reddish mark. Metasoma black; 1 st sternite sometimes with reddish base; 2 nd tergite with yellow band or arched spot in apical 0.25; 3 rd tergite yellow in the basal part (length 0.5 centrally and 0.25 laterally). Legs yellow; hind coxa brown to blackish; hind femur with some brownish suffusion; hind tibia with narrow brown apex (0.5 - 1.0 × tibial width). Pterostigma hyaline, with fuscous margins. ³. Body length 3.0 mm. Flagellum with 22 - 23 segments; 1 st flagellar segment 7.8 - 8.0 × as long as wide and 0.65 - 0.75 × as long as eye; 2 nd segment 5.4 × as long as wide. Temple slightly to moderately narrowed behind eye, dorsally 0.7 - 0.78 × as long as eye. OED 1.4 - 1.6 × and OOD 0.9 × ocellar diameter. Face coarsely punctate, its width 1.0 × combined length of face and 1.0 × eye length, sides parallel. Mandible with two equal teeth. MI 0.4. Mesosoma moderately depressed, 1.8 - 2.0 × as long as high. Mesoscutum rather densely punctate medially, with sparse punctures laterally. Mesopleuron with sparse to rather dense punctures ventrally. Propodeum carinate as in ♀. Hind femur 4.0 - 4.4 × as long as wide. Inner apical spur of hind tibia 0.55 × as long as hind metatarsus. Hind claws without visible teeth. 1 st tergite 2.5 - 3.1 × as long as wide; postpetiole with longitudinal striation. 2 nd tergite 1.0 - 1.1 × as long as wide. Thyridium comma-shaped. Stylet 1.2 - 1.4 × as long as 2 nd hind tarsomere, slightly clubbed apically. Color: Head yellowish; stemmaticum brown. Scape, pedicel and basal flagellomeres yellow, flagellum infuscate in distal 3 / 4. Mesosoma yellowish or reddish; mesoscutum with two lateral and one fronto-median brown to blackish stripes, sometimes completely reddish-yellow; scutellum brown, sometimes reddish-yellow; propodeum blackish or brown. Metasoma blackish; 1 st tergite reddish basally; 2 nd tergite with a transversal band or triangular yellow spot in apical 0.2 - 0.3; 3 rd tergite yellow in basal 0.5; following tergites brown or slightly vespoid. Legs yellowish; hind tibia infuscate in apical 0.1 - 0.2. Pterostigma hyaline. H o s t s: Apanteles s. lat. (Hym., Braconidae) in Phyllonoryctes blancardella (FABRICIUS, 1781) (Lep., Gracillariidae) (ZSM), Pholetesor circumscriptus (NEES) in Phyllonorycter lantanella (EDI), Pholetesor nanus (REINHARD) in Phyllonorycter strigulatella (EDI),? Pholetesor nanus (REINHARD) in Phyllonorycter anderidae (EDI), Pholetesor nanus (REINHARD) in Phyllonorycter spinolella (EDI), Pholetesor nanus (REINHARD) in Phyllonorycter hilarella (EDI), Pholetesor nanus (REINHARD) in Phyllonorycter dubitella (EDI), Phyllonorycter salicolella (EDI), Pholetesor sp. in Catoptilia rufipennella (ÜBERNER, 1813) (Lep., Gracillariidae) (EDI), Pholetesor laetus (MARSHALL) in Caloptilia semifascia (EDI), Pholetesor nanus (REINHARD) in Salicidella aspinolella (EDI), [primary host] Bucculatrix thoracella (THUNBERG, 1794) (Lep., Bucculatricidae) (ZSM) D i s t r i b u t i o n: West Palaearctic; examined material from Czech Republic, Germany, Poland, Sweden, and United Kingdom.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFCFFF457B9FA23FD5C07C4.taxon	description	H o l o t y p e: (³) “ Harrlach / N-Bay, 17.7.72 Schwenke ” (ZSM), type examined. D e s c r i p t i o n: Ô. Body length 2.8 mm. Flagellum with 25 segments; 1 st flagellar segment 7.5 × as long as wide and 0.65 × as long as eye; 2 nd segment 5.0 × as long as wide. Temple short, but only slightly narrowed behind eye, dorsally 0.6 - 0.7 × as long as eye. OED 1.5 × ocellar diameter. Face coarsely punctate, its width 1.0 × combined length of face and clypeus and 0.9 × eye length, sides slightly divergent ventrally. Subantennal transverse carina slightly dipped centrally. Dorsal mandibular tooth slightly larger than ventral tooth. MI 0.3 - 0.4. Mesosoma not depressed, 1.7 × as long as high. Mesopleuron with sparse punctures ventrally, speculum smooth and shining. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia c. 2 × as long as wide; costula reaching at its middle. Area petiolaris slightly as long as wide. Hind femur 4.3 × as long as wide. Areolet sessile frontally; vein 1 cu-a slightly postfurcal by 0.2 × its length; distal part of metacarpus as long as width of pterostigma. 1 st tergite 2.9 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite as long as wide. Thyridium transverse, comma-shaped. Stylet slightly clubbed at apex, 1.3 × as long as 2 nd hind tarsomere. Color: yellowish. Stemmaticum blackish. Basal flagellomeres yellowish; flagellum fuscous distally. Mesoscutum yellowish, with brown spot fronto-medially and pale brownish lateral stripes. Propodeum blackish; metapleuron yellowish. Legs yellow; hind tibia and hind tarsomeres narrowly brownish at apices. Pterostigma hyaline. ♀ unknown. R e m a r k s: The only known Ô is closely related to M. (St.) formosus. It differs by the stouter mesosoma, very slender flagellum, and slightly clubbed tip of paramere. The transverse carina below antennal sockets appears slightly dipped medially, but the morphology is otherwise typical for the subgenus Stictopisthus. D i s t r i b u t i o n: Only known from Germany.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFDFFF257B9FBF8FBEC0049.taxon	description	D e s c r i p t i o n: Ô. Body length 4.5 mm. Flagellum with 37 segments; 1 st flagellar segment 5.0 × as long as wide and 0.7 × as long as eye; 2 nd segment 3.7 × as long as wide. Temple moderately and roundly narrowed behind eye, dorsally 0.4 × as long as eye. OED 1.8 × and OOD 0.8 × ocellar diameter. Face punctate, its width 1.1 × combined length of face and clypeus and 1.1 × eye length, with parallel sides. Ventral 0.4 of facial orbit and malar space striate. Mandible with two equal teeth. MI 0.9. Mesosoma moderately depressed, 1.7 × as long as high. Mesoscutum with rather dense punctures. Mesopleuron with finer dense punctures dorsally and with rather dense coarse punctures ventrally. Scuto-scutellar groove with c. 7 blunt longitudinal ridges. Propodeum completely carinate. Area superomedia 1.8 × as long as wide and 1.2 × as long as area petiolaris; costula reaching at its middle. Area petiolaris about as long as wide. Hind femur 4.6 × as long as wide. Hind claws without visible teeth. Areolet shortly sessile frontally; vein 2 m-cu reaching slightly proximad its middle. Vein 1 cu-a postfurcal by 0.5 × its length. Pterostigma rather narrow, c 3.0 × as long as wide. Distal part of metacarpus long, length 1.3 × width of pterostigma. 1 st tergite slender, 3.4 × as long as wide; postpetiole with rather coarse longitudinal rugae. 2 nd tergite 1.0 × as long as wide. Thyridium transversal-oval, at base of tergite. Stylet long, slightly clubbed apically, 1.6 × as long as 2 nd hind tarsomere. Color: Head with scape and pedicel yellow. Flagellum blackish. Frons medially, stemmaticum and occiput brownish. Mesoscutum and propodeum blackish, scutellum brown. Pronotum yellowish-red, mesopleuron and metapleuron reddish. Hind edge of pronotum and tegula yellow. 1 st tergite black, red basally. 2 nd tergite black, with triangular reddish spot in apical half; 3 rd tergite blackish, with reddish band in basal 0.2. Following tergites blackish. Fore and mid legs reddish-yellow; hind coxa red with brown dorsal spot; hind femur reddish, with brown stripe externally; hind tibia cream-yellow, blackish in basal 0.1 and apical 0.2; hind tarsus black. Pterostigma brown. ♀ unknown. R e m a r k s: The ³ of this new species is characterized by superficially ridged scuto-scutellar groove, vein 2 m-cu reaching areolet slightly proximad its middle, black flagellum, red base of 1 st tergite, brown spot at hind coxa, basally and apically black hind tibia, and black hind tarsomere. D i s t r i b u t i o n: Only known from Italy.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFDFFF257B9FBF8FBEC0049.taxon	description	D e s c r i p t i o n: ♀. Body length 4.5 - 5.5 mm. Flagellum with 28 segments; 1 st flagellar segment 3.1 - 3.5 × as long as wide and 0.45 × as long as eye; 2 nd segment 2.2 × and preapical flagellomere 1.7 × as long as wide. Head wider than mesosoma. Temple slightly widened or slightly narrowed behind eye, moderately narrowed caudally, dorsally 0.7 - 0.9 × as long as eye. OED 1.6 - 2.1 × and OOD 1.1 × ocellar diameter. Occipital carina complete. Mandible and face strongly swollen. Face coarsely punctate, its width 1.2 × 1.3 × combined length of face and clypeus and 1.2 - 1.3 × eye length. Clypeus centrally impressed, apical margin with short lateral lamella. Gena with sparse punctures ventrally. MI 0.2 - 0.3. Mesosoma strongly depressed, 2.1 - 2.4 × as long as high. Pronotum with fine punctures dorsally, almost smooth ventrally. Mesopleuron with rather sparse punctures ventrally, denser in dorsal parts; metapleuron rather densely punctate. Scutellum with sparse punctures. Scuto-scutellar groove smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia c. 2.0 × as long as wide; costula reaching at its middle. Area petiolaris 1.0 - 1.2 × as wide as long. Hind femur 2.9 - 3.2 × as long as wide. Areolet sessile frontally; vein 2 m-cu reaching slightly proximad its middle. Vein 1 cu-a strongly postfurcal by 0.5 - 0.8 × its length. Pterostigma 3.1 × as long as wide; distal part of metacarpus rather short, 0.5 - 1.0 × as long as width of pterostigma. 1 st tergite 2.2 - 2.4 × as long as wide; postpetiole finely aciculate. 2 nd tergite 0.9 - 1.0 × as long as wide. Thyridium transverse and comma-shaped. Ovipositor sheath short, 4.2 - 5.0 × as long as wide and 0.7 - 0.9 × as long as hind metatarsus. Color: black. Head yellowish; occiput centrally brownish. Pronotum yellowish; mesoscutum black, with H-sized yellow-brownish spot; scutellum brownish; mesopleuron reddish-yellow, with diffuse brownish suffusion dorsally; metapleuron and propodeum blackish. 2 nd tergite with triangular yellow spot in apical 1 / 3 - 1 / 2; 3 rd tergite reddish-yellow, blackish laterally and apically; 4 th to 7 th tergites blackish, often slightly vespoid. Hind coxa brownish or reddish, hind femur sometimes with brownish suffusion apically; hind tibia completely yellowish or infuscate in apical 0.2 (1.0 × tibial width). Pterostigma hyaline frontally, caudal margin often brownish. ³ (holotype). Body length 5.0 mm. Head missing. Mesosoma moderately depressed, 2.0 × as long as high. Mesoscutum densely punctate; mesopleuron with fine dense punctures fronto-dorsally and with coarser dense punctures ventrally. Scuto-scutellar groove 2.6 × as wide as long, smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia rather slender; costula reaching at its middle. Area petiolaris wider than long. Hind femur 3.9 × as long as wide. Areolet shortly sessile frontally; vein 2 m-cu reaching slightly proximad its middle; vein 1 cu-a strongly postfurcal by 0.7 × its length. Pterostigma 2.7 × as long as wide. Distal part of metacarpus long, length 1.0 × width of pterostigma. Postnervulus intercepted in its middle. Nervellus of hind wing inclivous. 1 st tergite 2.6 × as long as wide; postpetiole coarsely striate. 2 nd tergite 1.5 × as long as wide. Thyridium comma-shaped. Stylet long, stick-shaped, 1.4 × as long as 2 nd hind tarsomere. Color: Mesosoma blackish; mesoscutum with H-shaped central reddish-yellow spot; scutellum brownish; pronotum and mesopleuron reddish-brown. Hind edge of pronotum and tegula yellow. 1 st tergite black. 2 nd tergite black, with yellowish band in apical 0.25. 3 rd tergite yellow in basal half, blackish apically. Following tergites black. Legs reddish-yellow; hind coxa reddish-brown; hind femur with diffuse reddish-brown suffusion in apical half; hind tibia yellowish, infuscate in apical 0.2. Pterostigma hyaline, margins slightly darker. R e m a r k s: The head of the holotype is apparently lost. A head glued on a small card and placed to this type does not belong to a Mesochorinae species. I have not seen any other ³³ of this species. D i s t r i b u t i o n: West Palaearctic; examined material from Austria and Germany.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFBFFEF57B9FB83FC31060D.taxon	description	Paratype: (³) “ Mongolia, G. - Altai, Mt. Khasagt Kharkan, 15 km S Jargalan, Kerzner, 14.8.1970 ” (St. Petersburg). D e s c r i p t i o n: ♀. Body length 4 mm. Flagellum with 26 segments; 1 st flagellar segment 4.3 × as long as wide and 0.57 × as long as eye; 2 nd segment 2.9 × and preapical flagellomere 2.2 × as long as wide. Temple roundly narrowed behind eye, dorsally 0.8 × as long as eye. OED 2.2 × ocellar diameter. Occipital carina complete. Face with coarse punctures and transverse aciculation, its width 1.5 × combined length of face and clypeus and 1.2 × eye length, with parallel sides. Clypeus impressed, almost smooth. Mandible strongly swollen in apical half, with two equal teeth. MI 0.5. Mesosoma strongly depressed, 2.2 × as long as high. Side of pronotum smooth; mesoscutum, mesopleuron, and metapleuron rather densely punctate. Scuto-scutellar groove smooth. Hind femur 3.2 × as long as wide. Areolet sessile frontally; vein 1 cu-a strongly postfurcal by 0.8 × its length. Pterostigma 2.5 × as long as wide. Distal part of metacarpus short, c. 0.7 × as long as width of pterostigma. 1 st tergite 2.3 × as long as wide; postpetiole finely aciculate. 2 nd tergite 0.8 × as long as wide. Thyridium transverse, comma-shaped. Ovipositor sheath 4.2 × as long as wide and 0.6 × as long as hind metatarsus, not distinctly narrowed and slightly bent upwards apically. Color: black. Head reddish; mandible except teeth, facial orbit and gena yellowish. Flagellum reddish, slightly infuscate in distal third. Mesosoma reddish; mesoscutum with two blackish lateral stripes and blackish fronto-medial spot; propodeum blackish, brownish in apical third. 1 st sternite basally reddish; 1 st tergite black, with reddish apical spot; 2 nd tergite red, with basolateral black stripes; 3 rd tergite reddish, brownish in apical half; following tergites brownish, slightly vespoid. Legs reddish-yellow; hind femur more brownish-yellow; hind tibia cream-yellow, narrowly brown at apex (0.5 × tibial diameter). Pterostigma yellowish, margins brownish. ³. Body length 3.5 mm. Flagellum with 24 segments; 1 st flagellar segment 5.3 × as long as wide and 0.61 × as long as eye; 2 nd segment 3.9 × and preapical segment 2.5 × as long as wide. Temple roundly narrowed behind eye, dorsally 0.8 × as long as eye. OED 1.4 × ocellar diameter. Occipital carina complete. Face with coarse and irregular transverse aciculation, its width 1.2 × combined length of face and clypeus and 1.1 × eye length, with parallel sides. Clypeus slightly impressed, almost smooth. Mandible slightly swollen in apical half, with two equal teeth. MI 0.5. Mesosoma moderately depressed, 2.0 × as long as high. Side of pronotum smooth. Mesoscutum, mesopleuron, and metapleuron rather densely punctate. Scuto-scutellar groove smooth. Areolet sessile frontally; vein 1 cu-a strongly postfurcal by 0.8 × its length, distal part of metacarpus c 0.7 × as long as width of pterostigma. 1 st tergite 2.1 × as long as wide; postpetiole almost smooth, with central rim. 2 nd tergite 0.8 × as long as wide. Thyridium comma-shaped. Stylet stick-shaped, slightly clubbed apically, 1.2 × as long as 2 nd hind tarsomere. Color: Head reddish; mandible except teeth, facial orbit and gena yellowish. Flagellum reddish, slightly infuscate in distal third. Mesosoma reddish; mesoscutum with two blackish lateral stripes and blackish fronto-median spot; propodeum blackish, in apical third brownish. 1 st sternite with reddish base. 1 st tergite black, with reddish apical spot; 2 nd tergite red, with basolateral black spots; 3 rd tergite reddish, more brownish in the apical half; following tergites brownish, slightly vespoid. Legs reddish-yellow; hind femur more brownish-yellow; hind tibia cream-yellow, narrowly brown at apex (1.0 × tibial diameter); hind metatarsus cream-yellow, apically brown; following hind tarsomeres brownish. Pterostigma yellowish, margins brownish. R e m a r k s: This species is closely related to Mesochorus macrocephalus STROBL and probably represents a subspecies of the latter. It differs by longer basal flagellar segments, wider malar space and a slightly different color pattern. D i s t r i b u t i o n: Only known from Mongolia.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFFBFFEF57B9FB83FC31060D.taxon	description	H o l o t y p e: (♀) “ Maroc, Dariet Aoua, 20.7.58 ” (American Entomological Institute), type not examined. D e s c r i p t i o n: ♀. Body length 2.9 - 3.3 mm. Flagellum with 20 - 23 segments; 1 st flagellar segment 3.5 - 3.8 × as long as wide and 0.43 - 0.45 × as long as eye; 2 nd segment 2.7 - 2.8 × and preapical segment 1.7 × as long as wide. Temple moderately to strongly and roundly narrowed behind eye, dorsally 0.6 - 0.8 × as long as eye. OED 1.4 - 1.8 × and OOD 1.4 × ocellar diameter. Occipital carina complete medially. Frons finely granulated laterally. Face with coarse but superficial punctures, its width 1.0 × eye length and 1.2 × combined length of clypeus and face. Mandible with two equal teeth. MI 0.5 - 0.7. Mesosoma slightly or moderately depressed, 1.8 - 2.0 × as long as high. Mesopleuron coarsely and rather densely punctate; metapleuron with finer and denser punctures. Scuto-scutellar groove slit-shaped, smooth. Area basalis and area superomedia confluent; costula reaching at its middle. Area petiolaris 0.9 × as long as wide. Hind femur 3.1 - 3.3 × as long as wide. Inner apical spur of hind tibia 0.65 × as long as hind metatarsus. Hind claws without visible teeth. Areolet oblique, slightly sessile frontally; vein 2 mc-u reaching at its middle; vein 1 cu-a strongly postfurcal by 0.6 × its length. Postnervulus intercepted in its middle. Pterostigma 2.9 × as long as wide; distal part of metacarpus short, 0.1 - 0.5 × of pterostigma width. Hind wing with 4 distal hamuli; nervellus slightly inclivous. 1 st tergite 2.0 × as long as wide; postpetiole aciculate. 2 nd tergite 0.7 × as long as wide. Ovipositor sheath 5.5 - 6.5 × as long as wide and 0.8 - 0.9 × as long as hind metatarsus, sometimes slightly narrowed and bent upwards apically. Color: Black. Face, clypeus, gena, frontal orbit and vertex yellow; frons medially and temple reddish, outer orbit sometimes red; occiput brown, sometimes also stemmaticum. Pronotum, mesopleuron and metapleuron centrally reddish; mesoscutum with four lateral and submedian yellowish stripes, confluent frontally; mesosternum often ± brownish, scutellum with yellowish sides, brown centrally; propodeum blackish. Base of 1 st sternite rufous. 1 st tergite black, reddish basally and apically; 2 nd tergite reddish-yellow, with basolateral infuscate stripes; 3 rd tergite yellowish in basal 0.6, brown apically; following tergites completely brown or with narrow apical yellow margins (slightly vespoid). Legs yellowish; hind tibia cream-yellow, not or indistinctly and narrowly darkened basally and apically. Pterostigma hyaline, with darker margins. ³. Body length 3.0 - 3.2 mm. Flagellum with 22 - 24 segments; 1 st flagellar segment 4.3 - 4.9 × as long as wide and 0.60 × as long as eye; 2 nd segment 3.3 - 3.4 × and preapical segment c. 2.0 × as long as wide. Temple moderately and roundly narrowed behind eye, dorsally 0.8 × as long as eye. OED 1.4 - 1.5 × and OOD 1.5 × ocellar diameter. Facial width 1.2 × eye length and 1.2 × combined length of face and clypeus. MI 0.7. Mesosoma not or slightly depressed, 1.7 - 2.0 × as long as high. Mesopleuron with coarse and dense but somewhat superficial punctures. Areolet oblique; vein 2 m-cu reaching proximad its middle. Vein 1 cu-a postfurcal by 0.4 × its length, strongly inclivous. Pterostigma wide, 2.5 × as long as wide. Stylet 1.3 × as long as 2 nd hind tarsomere. Color: Flagellum yellowish, fuscous distally. Head yellowish; stemmaticum and occiput brownish. Pronotum and mesopleuron rufous; mesosternum partly and metapleuron completely brownish; mesoscutum brownish, with four longitudinal yellow stripes, confluent frontally; scutellum brownish, with lateral yellow stripes; propodeum black basally and reddish in apical 1 / 3, sometimes entirely red. 1 st tergite black, with basal and apical yellow bands; 2 nd tergite blackish, with large triangular apical spot (2 / 3 of tergite length) or yellow with blackish latero-basal stripes; 3 rd tergite yellowish, apical margin and sides brownish; following tergites brown, with narrow yellowish apical margins. Fore and mid coxae and trochanters, hind tibia and tarsus cream-yellow; legs otherwise reddish-yellow. Pterostigma pale yellow, with darker margins. Var.: 1 ♀ from Kirgizhia: Hind tibia slightly red apically, and hind tarsus pale. H o s t s: Apanteles sp. (Hym. Braconidae) in Pempelia genistella DUPONCHEL, 1837 (Lep., Pyralidae) (EDI). D i s t r i b u t i o n: Transpalaearctic; examined material from Bulgaria *, Croatia *, Iran *, Jordan *, Kyrgyzstan *, Morocco, Mongolia *, Spain *, Tunisia *, Turkey.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE6FFEE57B9FDC0FD220562.taxon	description	Petersburg). D e s c r i p t i o n: ♀. Body length 3.9 mm. Flagellum with 27 segments; 1 st flagellar segment 6.9 × as long as wide and 0.59 × as long as eye; 2 nd segment 4.7 × and preapical segment 2.0 × as long as wide. Temple slightly widened behind eye and slightly narrowed apically, dorsally as long as eye. OED 2.0 × and OOD 1.1 × ocellar diameter. Occipital carina complete. Vertex with sparse punctures, gena coarsely and densely punctate. Frons almost smooth, Face with coarse dense punctures, its width 1.1 × combined length of face and clypeus and 1.1 × eye length, with parallel sides. Clypeus impressed, almost smooth. Mandible not swollen, with two equal teeth. MI 0.5. Mesosoma strongly depressed, 2.1 × as long as high. Side of pronotum with fine sparse punctures dorsally, almost smooth ventrally. Mesoscutum with fine rather dense setiferous punctures. Scuto-scutellar groove slit-shaped, smooth. Mesopleuron densely punctate dorso-frontally, with very sparse punctures ventrally. Metapleuron with dense and coarser punctures. Propodeum with complete carination, but area basalis and area superomedia confluent. Costula reaching area superomedia at its middle. Area petiolaris about as long as wide. Hind femur 3.4 × as long as wide. Inner apical spur of hind tibia 0.58 × as long as hind metatarsus. Hind claws without visible teeth. Areolet pointed frontally; vein 2 m-cu reaching proximad its middle. Vein 1 cu-a moderately postfurcal by 0.3 × its length. Pterostigma 3.0 × as long as wide; distal part of metacarpus long, c. 1.0 × as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus vertical, not intercepted. 1 st tergite 2.5 × as long as wide; postpetiole with rather coarse longitudinal rugae. 2 nd tergite 0.9 × as long as wide. Thyridium transverse-oval. Ovipositor sheath pilose, 6.3 × as long as wide and 0.9 × as long as hind metatarsus, not distinctly narrowed and slightly bent upwards apically. Color: black. Head reddish; face except red facial orbit brownish. Mandible except teeth and palps yellow. Stemmaticum and occiput brown. Flagellum blackish; three basal flagellomeres, scape and pedicel yellowish. Mesosoma black; hind edge and ventral spot on pronotum and tegula yellow. Tergites black; 2 nd tergite with reddish-yellow band in apical 0.3; 3 rd tergite reddish-yellow antero-medially, black laterally and apically. Legs yellow; hind coxa reddish; hind tibia cream-yellow, brown at apical 0.15 (1 × tibial diameter); hind tarsomeres yellowish, with reddish tips. Pterostigma hyaline. ³ unknown. R e m a r k s: This new species resembles Mesochorus macrocephalus STROBL but differs by its sparsely punctate mesopleuron, ± widened temple and normal mandible which is not distinctly swollen as in Mesochorus macrocephalus STROBL. D i s t r i b u t i o n: Only known from Far East Russia.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE7FFEE57B9FE5BFCAC009A.taxon	description	H o l o t y p e: (³) “ Litovel (Moravia) 6.58 ex Archips cr. ” (ZSM), type examined. D e s c r i p t i o n: ³. Body length 3.4 mm. Flagellum missing. Temple moderately and roundly narrowed behind eye, dorsally 0.8 × as long as eye. OED 1.3 × ocellar diameter. Face coarsely punctate, its width 1.2 × combined length of face and clypeus and 1.1 × eye length, sides convergent ventrally. Mandible with two equal teeth. MI 0.5. Mesosoma moderately depressed, c 2.1 × as long as high. Mesopleuron coarsely and rather densely punctate, speculum smooth and shining. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia slender, 2.3 × as long as wide, costula reaching at its middle. Area petiolaris as long as wide. Hind femur 3.8 × as long as wide. Areolet sessile frontally. Vein 1 cu-a postfurcal by 0.4 × of their length; distal part of metacarpus length c. 0.8 × width of pterostigma. 1 st tergite 2.3 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite 0.9 × as long as wide. Thyridium transverse, comma-shaped. Stylet long, not clubbed apically, c. 1.7 × as long as 2 nd hind tarsomere. Color: Body reddish-yellow. Mesoscutum with brownish spot antero-medially and with brownish lateral stripes; propodeum brown in basal 2 / 3. 1 st tergite black; 1 st sternite yellow basally; 2 nd tergite brown, with yellow band in apical 0.4; 3 rd tergite completely yellow; following tergites brownish. Pterostigma hyaline. ♀ unknown. Host: Archips crataegana (HÜBNER, 1799) (Lep., Torticidae) (ZSM). D i s t r i b u t i o n: Only known from Czech Republic (Moravia).	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE7FFEC57B9FB53FE49071C.taxon	description	H o l o t y p e: (♀) “ Dessau 4 SW-SSW 18.5.1993 100 / 93 H. Zoerner ” (SDEI, Müncheberg), type examined. syn. Mesochorus roccanus SCHWENKE, 1999: 59, synonymized by RIEDEL (2019). H o l o t y p e: (³) “ I, VR, Garda Rocca, 100 - 250 m, 20.5.83 Haeselb. ” (ZSM), type examined. syn. nov. Stictopisthus madeirensis SCHWENKE, 1999: 31, ♀ ³. H o l o t y p e: (♀) “ Madeira Machico V. 82, ex Palpita unionalis via Choeras suffolkiensis ” (ZSM), type examined. D e s c r i p t i o n: ♀. Body length 3.0 - 3.5 mm. Flagellum with 26 - 27 segments; 1 st flagellar segment 3.6 - 4.6 × as long as wide and 0.50 - 0.70 × as long as eye; 2 nd segment 2.6 - 2.8 × and preapical segment 1.7 - 2.0 × as long as wide. Temple roundly narrowed behind eye, dorsally 0.7 - 0.8 × as long as eye. OED 1.4 - 1.8 × and OOD 0.9 - 1.0 × ocellar diameter. Frons almost smooth. Face with coarse and irregular transverse rugosepunctation, its width 1.2 - 1.3 × combined length of face and clypeus and 1.1 - 1.2 × eye length, with parallel sides. Clypeus impressed centrally, almost smooth. Mandible with two equal teeth. MI 0.4. Mesosoma moderately to strongly depressed, 2.3 - 2.5 × as long as high. Mesoscutum densely punctate. Scuto-scutellar groove slit-shaped, smooth. Mesopleuron coarsely and rather densely punctate ventrally; speculum smooth and shining. Metapleuron with fine rather dense punctures. Propodeum completely carinate, but area basalis and area superomedia confluent. Sides of area superomedia narrowed in apical half; costula reaching at its middle. Area petiolaris as long as wide or slightly wider than long. Hind femur 3.0 - 3.3 × as long as wide. Inner apical spur of hind tibia 0.65 × as long as hind metatarsus. Hind claws without visible teeth. Areolet sessile frontally; vein 2 m-cu reaching its middle. Vein 1 cu-a strongly postfurcal by 0.8 - 1.0 × its length; postnervulus intercepted slightly distad its middle. Pterostigma 2.4 - 2.7 × as long as wide; distal part of metacarpus 1.0 × as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus slightly inclivous. 1 st tergite 2.3 - 2.9 × as long as wide; postpetiole coarsely aciculate or striate. 2 nd tergite 1.0 - 1.2 × as long as wide. Thyridium transverse, comma-shaped. Ovipositor sheath 4.8 - 5.2 × as long as wide and 0.9 - 1.0 × as long as hind metatarsus, not narrowed and slightly bent upwards apically. Color: Black. Head reddish-brown or yellowish-brown; stemmaticum often and occiput brown to black. Mesoscutum blackish, with H-shaped central fuscous spot or four longitudinal fuscous stripes which are confluent frontally; side of pronotum, mesopleuron and metapleuron reddish-brown, mesopleuron sometimes blackish dorsally; mesosternum with blackish suffusion; propodeum blackish at anterior half, reddish-brown apically. 1 st tergite blackish; 2 nd tergite blackish, with large triangular yellowish spot in apical half; 3 rd tergite with narrow yellow basal band or yellow basally and centrally, brown apically; following tergites brown, with narrow yellowish or greyish apical margins. Legs reddish-brown; hind coxa brownish; hind femur brown or with brown suffusion; hind tibia cream yellow, brownish in apical 0.2 - 0.3 (1 × tibial width); hind tarsus brown or blackish, metatarsus yellow in basal 2 / 3. Pterostigma brownish. ³. Body length 3.5 - 4.5 mm. Flagellum with 27 - 29 segments; 1 st flagellar segment 6.0 × as long as wide and 0.60 - 0.63 × as long as eye. Temple moderately narrowed behind eye, dorsally 0.7 - 0.8 × as long as eye. OED 1.4 - 1.8 × ocellar diameter. Facial width 1.1 - 1.2 × combined length of face and clypeus and 1.1 × eye length, with parallel sides. Mandible with two equal teeth. Mesosoma moderately depressed, 1.9 - 2.1 × as long as high. Mesoscutum densely punctate; mesopleuron with sparse to dense punctures. Propodeum completely carinate, but area basalis and area superomedia confluent. Hind femur 3.5 - 4.2 × as long as wide. Areolet pointed or sessile frontally; vein 1 cu-a strongly postfurcal by 0.8 × its length. Pterostigma wide, 2.3 - 2.5 × as long as wide. Distal part of metacarpus long, length 1.0 × width of pterostigma. 1 st tergite 2.6 - 2.8 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite 0.9 - 1.0 × as long as wide. Thyridium comma-shaped, at base of tergite. Stylet long, stick-shaped or slightly clubbed apically, 1.4 - 1.8 × as long as 2 nd hind tarsomere. Color: head yellow. Palps, gena, mandible (except teeth), face, frontal margin and hind edge of pronotum, tegula, wing base, and fore and mid coxae and trochanters cream-yellow. Flagellum yellow basally, ± infuscate distally. Mesosoma reddish-yellow; mesoscutum with two brownish to blackish lateral stripes and blackish fronto-median spot; propodeum black in frontal 1 / 2 - 2 / 3. 1 st sternite dark reddish; 1 st tergite black; 2 nd tergite black, with triangular or arched yellow spot in apical half; 3 rd tergite brown, with tongue-shaped yellow spot in basal 2 / 3; following tergites brown or vespoid. Legs yellow, hind femur with brownish suffusion apically, hind tibia cream-yellow, brownish in apical 0.1 - 0.2 (1.0 - 1.5 × tibial width); hind tarsomeres yellowish, with ± brown tips. Pterostigma brown, pale yellow proximally and sometimes distally. H o s t s: Carcina quercana (FABRICIUS, 1775) (Lep., Depressariidae) (ZSM), Acleris forsskaleana (LINNAEUS, 1758) (Lep., Torticidae) (ZSM), Apanteles (Choeras) dorsalis (SPINOLA, 1808) (Hym. Braconidae) in Palpita vitralis (ROSSI, 1794) (Lep., Crambidae) (EDI, ZSM). R e m a r k s: This species is closely related to Mesochorus flavescens FONSCOLOMBE. It differs by a darker coloration of hind leg and pterostigma, stouter ovipositor sheath and transversely rugose-punctate face. D i s t r i b u t i o n: West Palaearctic; examined material from Czech Republic *, Germany, Italy, Madeira.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE5FFEB57B9FCD2FD2607EA.taxon	description	Paratypes: (♀) “ Wood, Odessa region, 25 km yu Kaushani, Les, Kasparyan 12 VI 1974 ” (St. Petersburg); (♀) “ SMTP, Trap 50 Coll 1223 ” (Stockholm); (3 ³³) “ Bylyia, Chit. Region, birch 22 УI 975 ” (St. Petersburg), (♀ 2 ³³) “ Turkey: Samsun University campus 41 ° 22´N 36 ° 11´E, 22.6. - 4.7.2014 Barták, Kubik ” (Linz and coll. Riedel); (♀) “ 25 - 28 VI 1999, Taman vill., Krasnodar reg., NNW Caucasus, leg. Osipov ” (coll. Riedel). D e s c r i p t i o n: ♀. Body length 2.5 - 3.0 mm. Flagellum with 23 - 26 segments; 1 st flagellar segment 5.8 - 6.0 × as long as wide and 0.6 - 0.7 × as long as eye; 2 nd segment 4.8 × and preapical segment c. 2 × as long as wide. Temple strongly and roundly narrowed behind eye, dorsally 0.7 - 0.8 × as long as eye. OED 2.0 - 2.2 × ocellar diameter. Occipital carina complete. Face punctate, its width 1.1 - 1.2 × combined length of face and clypeus and 1.2 - 1.3 × eye length, with parallel sides. Malar space and ventral 0.3 of facial orbit striate. Mandible with two equally sized teeth. MI 0.8 - 1.0. Mesosoma not depressed, 1.7 - 1.8 × as long as high. Mesoscutum densely punctate medially, but almost smooth and shining laterally. Mesopleuron with ± extended fine rugosity centrally, with very sparse coarse punctures ventrally and dorsally. Scuto-scutellar groove moderately widened, sometimes with fine longitudinal ridges. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia 2 × as long as wide; costula reaching at its middle. Area petiolaris hexagonal, as long as wide or slightly longer. Hind femur 4.0 - 4.4 × as long as wide. Areolet sessile frontally; vein 1 cu-a strongly postfurcal by 0.7 - 1.3 × its length. Pterostigma 3.0 × as long as wide; distal part of metacarpus about as long as width of pterostigma. 1 st tergite 2.3 - 2.7 × as long as wide; postpetiole coarsely aciculate. 2 nd tergite 0.8 - 0.9 × as long as wide. Thyridium large, transversely oval, at base of tergite. Ovipositor sheath stick-shaped, 8.2 - 8.7 × as long as wide and 0.8 - 0.9 × as long as hind metatarsus, slightly bent upwards at apex. Color: black. Face, stemmaticum and occiput brownish; orbits widely yellowish; malar space and mandible (except teeth) yellow to cream-yellow. Scape, pedicel, and 1 st flagellomere (sometimes also 2 nd flagellomere) yellowish, following flagellomeres fuscous. Mesosoma black; pronotum brownish, its margins paler. Metasoma brownish; 1 st tergite black; 1 st sternite rufous basally; 2 nd tergite with a triangular yellowish spot in the apical 0.3 - 0.4. 3 rd tergite brown to black, following tergites blackish, 6 th and 7 th tergites sometimes brownish. Legs yellowish; hind coxa brown; hind femur sometimes slightly darkened; hind tibia in apical 0.15 infuscate; hind tarsomeres yellowish, with brownish tips. Pterostigma hyaline to ochreous-yellow. ³. Body length 2.2 mm. Flagellum with 26 - 27 segments; 1 st flagellar segment 0.73 × as long as eye. Temple strongly narrowed behind eye, dorsally 0.8 × as long as eye. OED 1.3 × ocellar diameter. Facial width 1.0 × combined length of face and clypeus and 1.1 × eye length. MI 0.8. Mesosoma 1.7 - 1.8 × as long as high. Mesopleuron punctate, with a small finely rugose central area. Hind femur 4.4 × as long as wide. Pterostigma 3.0 × as long as wide; vein 1 cu-a strongly postfurcal by 0.8 × its length. Stylet slightly clubbed at apex. Color: Black. Face, mandible, clypeus, gena and orbits, scape, pedicel and basal two flagellomeres yellowish or reddish-yellow. Stemmaticum, occiput, vertex and flagellum distally brown. Mesosoma dark brown; pronotum, mesopleuron and metapleuron brownish-yellow. Metasoma brown; 1 st sternite reddish at base; 2 nd tergite pale yellow, with basolateral brown stripes; 3 rd tergite with central yellow spot in the basal 2 / 3. Legs yellow; hind coxa reddish-yellow; hind tibia and tarsomeres with narrow darkened apices; distal hind tarsomere brown. Pterostigma hyaline. R e m a r k s: This new species is closely related to Mesochorus (Stictopisthus) formosus BRIDGMAN, but differs by the strongly narrowed temple and partly rugose mesopleuron. D i s t r i b u t i o n: Sweden, Russia, Turkey, Ukraine.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE2FFEB57B9FBE3FBED018F.taxon	description	H o l o t y p e: (³) “ Serooskerke / NL, 24.8.67, De Jong ” (ZSM), type was initially glued on card but the labeled card in the ZSM is actually empty. The type is apparently lost. Description (translated from SCHWENKE 1999: 32): ³. 2.8 mm. As tenuigaster, but: temple as long as eye width; 2 nd and 3 rd tergites wider than long. 1 st tergite red basally, widely whitish apically; 3 rd tergite in apical half and following tergites black (- brown). Color of metasoma: red-black-whitish-black. Host: Adoxophyes orana (FISCHER VON RÖSLERSTAMM, 1834) (Lep., Tortricidae). D i s t r i b u t i o n: Only known from Netherlands. Mesochorus (Stictopisthus) persicus RIEDEL, AMERI, TALESHI & EBRAHIMI, 2019,	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE0FFE957B9FDC8FD65020D.taxon	description	K. Schönitzer ” (ZSM). D e s c r i p t i o n: ♀. Body length 2.1 mm. Flagellum with 32 segments; 1 st flagellar segment 7.0 × as long as wide, 0.62 × as long as eye and 1.4 × as long as 2 nd segment; 2 nd segment 5.0 × and preapical segment 1.5 × as long as wide. Temple distinctly and roundly narrowed behind eye, dorsally 0.4 × as long as eye. OED 1.8 × and OOD 0.8 × ocellar diameter. Occipital carina widely obsolete medially. Frons with transverse microsculpture. Face coarsely punctate, its width 1.0 × combined length of face and clypeus, lateral margins slightly convergent Mandible with two equally sized teeth. MI 0.8. Mesosoma not depressed, 1.6 × as long as high. Mesoscutum densely punctate, shining. Mesopleuron densely and coarsely punctate. Scuto-scutellar groove with 5 coarse longitudinal ridges. Propodeum completely carinate. Area basalis trapezoid, c. 2 × as wide as long. Area superomedia 1.5 × as long as wide and 1.0 × as long as area petiolaris; costula reaching at its middle. Area petiolaris hexagonal, 1.2 × as long as wide. Hind femur 4.2 × as long as wide. Areolet sessile frontally and wider than long, vein 2 m-cu reaching at its middle; vein 1 cu-a strongly postfurcal by 0.5 × its length. Postnervulus intercepted far basad its middle. Distal part of metacarpus long, as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus slightly reclivous. 1 st tergite 2.8 × as long as wide; postpetiole with some longitudinal rugae. 2 nd tergite 1.2 × as long as wide. Thyridium transverse, comma-shaped. Ovipositor sheath 8.2 × as long as wide and 0.9 × as long as hind metatarsus, moderately narrowed in apical 0.5 and slightly upcurved apically, pilose. Color: reddish-yellow. Flagellum brownish in distal half. Palps, mandible except teeth, malar space, tegula and fore and mid legs yellowish. 2 nd tergite yellowish, with brownish triangular stripes antero-laterally. 3 rd tergite yellowish, slightly darkened in apical half. Hind tibia yellowish, slightly infuscate basally and in apical 0.1. Pterostigma hyaline. ³ unknown. R e m a r k s: The species is characterized by the stout mesosoma, densely punctate mesopleuron, reclivous nervellus of hind wing and strongly striate scuto-scutellar groove. D i s t r i b u t i o n: Only known from Pakistan.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFE1FFE757B9FF23FBDC06B7.taxon	description	A d d i t i o n a l m a t e r i a l: (³) Russia, East Siberia, lake Baikal, Cape Shartlai, 20 - 21 VI 2004, leg. O. Berlov (coll. Riedel). D e s c r i p t i o n: ♀. Body length 2.4 - 2.6 mm. Flagellum with 20 segments; 1 st flagellar segment 2.9 × as long as wide and 0.40 × as long as eye; 2 nd segment 2.1 × and preapical segment 1.5 × as long as wide; distal segments ± moniliform. Temple roundly narrowed behind eye, dorsally 0.7 × as long as eye. OED 2.4 - 2.6 × ocellar diameter. Facial width 1.3 - 1.4 × combined length of face and clypeus and 1.1 × eye length, transversally rugosestriate, sides slightly convergent ventrally. Mandible with two equal teeth. MI 0.6 - 0.7. Mesosoma slightly depressed, 2.1 × as long as high. Mesopleuron punctate dorsally and finely rugose-punctate ventrally. Area basalis and area superomedia confluent. Area superomedia c. 2 × as long as wide; costula reaching at its middle. Area petiolaris 0.8 × as long as wide and 0.31 - 0.33 × as long as propodeum. Hind femur 3.3 - 3.4 × as long as wide. Hind metatarsus 0.45 - 0.50 × as long as hind tibia. Hind claws without visible teeth. Areolet pointed frontally, vein 2 m-cu reaching at its middle. Vein 1 cu-a postfurcal by 0.5 × its length. Pterostigma wide, 2.7 × as long as wide; distal part of metacarpus short, stub-shaped, less than 0.5 × as long as width of pterostigma. 1 st tergite 2.4 × as long as wide; postpetiole with longitudinal rugae. 2 nd tergite 0.8 - 0.9 × as long as wide. Ovipositor sheath 5.0 - 5.5 × as long as wide and 0.8 - 0.9 × as long as hind metatarsus, with few setae, slightly bent upwards apically. Color: Face, clypeus, malar space and mandible except teeth reddish. Orbits brownish-yellow. Frontal orbit with widened spot opposite to lateral ocellus. Genal orbit narrowly yellow, outer orbit otherwise reddish. Palps brownish. Frons medially, ocellar field and occiput black. Scape brownish black, pedicel and flagellum pale brownish, slightly infuscate distally. Mesosoma black. Tegula brownish yellow, base of wing pale yellow. Mesoscutum with faint reddish stripes. Metasoma black; 2 nd tergite with reddish brown band in basal half and with narrow yellow apical band; apical tergites with narrow pale apical margins. Ovipositor sheath blackish. Legs brownish, base of mid coxa and entire hind coxa blackish, hind femur brownish infuscate, except apically. Hind tibia pale, basally and apically slightly infuscate, distal hind tarsomeres slightly infuscate. Wings subhyaline, veins pale brown, pterostigma brownish, slightly paler proximally and distally. ³. Body length 2.9 - 3.1 mm. Flagellum with 21 - 22 segments; 1 st flagellar segment 4.0 × as long as wide and 0.65 × as long as eye; 2 nd segment 3.0 × and preapical segment c. 2 × as long as wide. Temple roundly narrowed behind eye, dorsally 0.7 × as long as eye. OED 1.3 - 1.7 × ocellar diameter. Frons finely granulated. Face coarsely but superficially punctate, partly with fine transverse aciculation, its width 1.2 - 1.3 × combined length of face and clypeus and 1.2 × eye length, with parallel lateral margins. Mandible with two equally sized teeth. MI 0.5 - 0.7. Mesosoma slightly depressed, 1.9 - 2.0 × as long as high. Mesopleuron coarsely and densely punctate, speculum smooth and shining. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia c. 2 × as long as wide; costula reaching at its middle. Area petiolaris as long as wide, finely rugulose. Hind femur 3.6 - 4.0 × as long as wide. Hind claws with three visible basal teeth. Areolet sessile frontally, very oblique; vein 2 m-cu reaching proximad its middle. Vein 1 cu-a almost interstitial. Distal part of metacarpus very short, stub-like, 0.5 × as long as width of pterostigma. 1 st tergite 2.0 - 2.4 × as long as wide; postpetiole with coarse striation. 2 nd tergite 0.8 - 1.0 × long as wide. Thyridium transverse, comma-shaped. Stylet slightly clubbed at apex, 1.0 × as long as 2 nd hind tarsomere. Color: black. Face reddish-yellow. Mandible, gena, facial and frontal orbits cream-yellow. Vertical orbit with large wide yellowish spot, almost reaching lateral ocelli. Outer orbit more yellowish-red. Flagellum brown. Mesosoma black, mesoscutum with an indistinct dark reddish H-sized spot. Fore coxa sometimes and mid coxa brown; hind coxa black. Legs otherwise reddish-yellow; hind femur brownish or blackish; hind tibia yellow, fuscous in apical 0.15 (1 × tibial width). Metasoma black, 2 nd tergite with narrow cream-yellow apical margin. Pterostigma pale ochreous. Hosts unknown. D i s t r i b u t i o n: Transpalaearctic; studied material from Finland and East Siberia *.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFEEFFE657B9FD26FD27050A.taxon	description	H o l o t y p e: (³) “ Kishinev / UdSSR [Moldavia] 20. VI. 08, Talitzkij ” (ZSM), type examined. D e s c r i p t i o n: ³. Body length 4.0 mm. Flagellum with 24 - 28 segments; 1 st flagellar segment 0.63 × as long as eye; preapical segment 2.0 × as long as wide. Temple moderately narrowed behind eye, dorsally 0.7 × as long as eye. OED 1.2 - 1.3 × and OOD 1.4 × ocellar diameter. Face densely punctate, its width 1.1 - 1.2 × combined length of face and clypeus and 1.1 - 1.2 × eye length, sides parallel or slightly divergent ventrally. Mandible with two equal teeth. MI 0.6 - 0.8. Mesosoma moderately depressed, 1.8 - 2.1 × as long as high. Mesoscutum densely punctate. Mesopleuron coarsely and densely punctate, shining. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia 1.5 × as long as wide; costula reaching at its middle. Area petiolaris large, hexagonal, as long as wide. Hind femur 3.3 - 3.6 × as long as wide. Areolet sessile frontally. Vein 1 cu-a strongly postfurcal by 0.5 - 0.8 × its length. Pterostigma 2.5 - 3.5 × as long as wide. Distal part of metacarpus c 0.8 × as long as width of pterostigma. Hind wing with 5 distal hamuli. 1 st tergite 2.2 × as long as wide; postpetiole coarsely striate. 2 nd tergite 0.8 - 0.9 × as long as wide. Thyridium transverse, comma-shaped. Stylet stick-shaped, not clubbed or pointed apically, 1.2 - 1.5 × as long as 2 nd hind tarsomere. Color: Head, pronotum and tegula yellow. Flagellum yellow basally, distal flagellomeres ± ochreous or brownish. Mesosoma reddish-yellow; mesoscutum with a median and two lateral ochreous or brownish stripes; propodeum brownish in basal 2 / 3. 1 st tergite black, usually reddish basally, 1 st sternite rufous in basal half. 2 nd tergite blackish, with large triangular yellow mark in apical 2 / 3. 3 rd tergite yellow, brown in apical 1 / 3 - 1 / 4; following tergites brownish, slightly vespoid. Legs yellow; hind tibia ivory, brownish in apical 0.1 - 0.2; hind tarsomeres ivory, with ± brownish tips. Pterostigma pale brownish, sometimes hyaline centrally. ♀ unknown. D i s t r i b u t i o n: Transpalaearctic; examined material from Moldavia, and Russia * (St. Petersburg, Arkhangelsk region, Primorje region).	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFEFFFE657B9FEC3FC94016F.taxon	description	H o l o t y p e: (³) “ München / D 5.6.69, W. Schwenke ” (ZSM), type examined. A d d i t i o n a l m a t e r i a l: (³) Turkey: Akyaka, 37 ° 03´N 28 ° 20´E, 3 m, pasture & salty meadow, V. Bartak, ix. 2012 (Linz). D e s c r i p t i o n: ³. Body length 4.0 mm. Flagellum with 31 - 33 segments; 1 st flagellar segment 5.0 - 5.5 × as long as wide and 0.58 - 0.66 × as long as eye; 2 nd segment 3.8 - 4.7 × and preapical flagellomere 2.5 × as long as wide. Temple strongly narrowed behind eye, dorsally 0.6 × as long as eye. OED 1.2 × and OOD 0.9 × ocellar diameter. Occipital carina complete. Frons with fine transverse aciculation laterally. Face coarsely punctate, its width 1.0 × combined length of face and clypeus and 0.9 - 1.1 × eye length, sides slightly convergent ventrally. Mandible with two equal teeth. MI 0.3 - 0.4. Mesosoma not depressed, 1.7 - 1.8 × as long as high. Mesopleuron with sparse punctures ventrally, speculum smooth and shining. Scuto-scutellar groove with 7 longitudinal ridges. Propodeum completely carinate. Area basalis closed apically. Area superomedia short, 1.5 × as long as wide; costula reaching at its middle. Area petiolaris longer than wide. Legs slender; hind femur 4.5 × as long as wide. Inner apical spur of hind tibia 0.51 × as long as hind metatarsus. Areolet sessile or shortly stalked frontally, oblique; vein 2 m-cu reaching proximad its middle. Vein 1 cu-a postfurcal by 0.5 - 1.0 × its length. Postnervulus intercepted slightly basad its middle. Distal part of metacarpus long, 1.5 × as long as width of pterostigma. Hind wing with 4 distal hamuli; nervellus slightly reclivous. Metasoma very long and slender; 1 st tergite with fine lateral carinae, 3.4 × as long as wide; postpetiole with coarse aciculation. 2 nd tergite 2.2 - 2.5 × as long as wide. Thyridium triangular. Stylet slightly clubbed at apex, 0.9 - 1.0 × as long as 2 nd hind tarsomere. Color: reddish-yellow. Mesoscutum with two indistinct submedian yellowish longitudinal stripes; propodeum brown in basal 2 / 3. 1 st sternite yellowish in basal half, 1 st tergite yellowish apically; 2 nd tergite with brownish sides; 3 rd tergite brownish in apical 2 / 3; following tergites with indistinct median brownish spots. Legs yellowish; hind tibia with wide brownish-yellow rings at base and apex. Pterostigma hyaline. ♀ unknown. R e m a r k s: The ³ resembles the Eastern Palaearctic Mesochorus chinensis (UCHIDA, 1942). I was not able to study the type material of M. chinensis, but both species are probably synonymous. D i s t r i b u t i o n: Examined material from Germany and Turkey *.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
03AC87C4FFEFFFE457B9FA5EFD1507C0.taxon	description	Lectotype: (³) “ Uppsala Univ. Zool. Mus. Thunbergsaml. nr. 25273 Ichneumon unicinctor Sv. Typ ” (Uppsala), designated by Horstmann, 2004, type not examined. syn. Cryptus (Mesochorus) complanatus HALIDAY, 1838: 114, ♀. Lectotype: (♀) “ 3450 ” (Dublin), synonymized by SCHWENKE (1999: 31), type not examined. syn. Mesochorus aciculatus BRIDGMAN, 1881: 162, ♀. Type lost (FITTON 1976), synonymized by SCHWENKE (1999: 31). syn. Mesochorus laticeps THOMSON, 1886: 344, ♀. Lectotype: (♀) “ Bök 8 / 84 ” (Lund), synonymized by SCHWENKE (1999: 31), type not examined. D e s c r i p t i o n: ♀. Body length 3.0 - 3.9 mm. Flagellum with 23 - 28 segments; 1 st flagellar segment 3.1 - 3.7 × as long as wide and 0.45 - 0.50 × as long as eye; 2 nd segment 2.2 - 2.6 × and preapical flagellomere 1.8 × as long as wide. Head wide, 2.2 × as wide as long. Temple parallel or slightly widened behind eye, moderately narrowed apically, dorsally 0.8 × as long as eye. OED 1.9 - 2.3 × and OOD 1.0 × ocellar diameter. Occipital carina complete medially. Frons punctate medially, almost smooth laterally. Face punctate centrally, with some transverse irregular striae laterally, its width 1.4 - 1.5 × combined length of clypeus and face and 1.2 - 1.3 × eye length. Dorsal mandibular tooth often larger than ventral tooth. Clypeus slightly impressed, coarsely punctate. MI 0.6. Mesosoma strongly depressed, 2.5 - 2.9 × as long as high. Mesoscutum with moderately dense punctures (intervals as long as their diameter), with finer sparse punctures laterally. Mesopleuron with rather dense to dense punctures ventrally; punctures of metapleuron finer and denser. Scuto-scutellar groove slit-shaped, smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia c. 2 × as long as wide; costula reaching at its middle. Area petiolaris hexagonal, as long as or slightly as long as wide. Fore tibia swollen, 2.2 - 2.3 × as long as wide. Hind femur stout, 2.8 - 3.0 × as long as wide. Inner apical spur of hind tibia 0.63 × as long as hind metatarsus. Hind claws without visible teeth. Areolet sessile frontally; vein 2 m-cu reaching its middle. Vein 1 cu-a strongly postfurcal by 0.7 - 1.0 × its length; distal part of metacarpus about as long as width of pterostigma. Hind wing with 4 - 5 distal hamuli. Nervellus of hind wing vertical or slightly inclivous. 1 st tergite 2.2 - 2.4 × as long as wide; postpetiole aciculate. 2 nd tergite 0.9 × as long as wide. Thyridium comma-shaped, transverse. Ovipositor sheath 4.2 - 5.7 × as long as wide and 0.9 - 1.2 × as long as hind metatarsus, not distinctly narrowed and slightly bent upwards apically. Color: black. Palps, mandible and tegula yellow. Flagellum brownish, basal flagellomeres yellowish. Face yellowish or reddish-yellow; frons and wide orbits reddish-yellow; stemmaticum and occiput brown or black. Mesosoma black; mesoscutum sometimes with dark reddish H-shaped central spot; pronotum, mesopleuron and metapleuron in Eastern Palaearctic specimens ± reddish. 1 st tergite black; 2 nd tergite with yellow band in apical 0.3 - 0.4; 3 rd tergite yellow baso-medially, brown laterally and apically; following tergites brownish. Legs yellowish; mid coxa reddish, sometimes brownish; hind coxa often brown dorsally or ± black, hind femur sometimes with brownish suffusion, hind tibia usually narrowly brown apically (0.5 × tibial width). Pterostigma hyaline or yellowish. ³. Body length 4.0 mm. Flagellum with 23 - 28 segments; 1 st flagellar segment 5.6 × as long as wide and 0.57 - 0.62 × as long as eye; 2 nd segment 4.2 × and preapical segment 2.0 × as long as wide. Temple moderately and roundly narrowed behind eye. OED 1.5 × ocellar diameter. Frons and occiput with sparse punctures. Face densely punctate, its width 1.3 × combined length of face and clypeus and 1.1 × eye length, sides convergent ventrally. Mandible with two equally sized teeth, sometimes dorsal tooth slightly larger. MI 0.5. Mesosoma moderately depressed, 1.9 - 2.0 × as long as high. Mesoscutum and mesopleuron with coarse rather dense punctures, shining; pronotum smooth. Propodeum completely carinate, but area basalis and area superomedia confluent. Area superomedia c. 2 × as long as wide; costula reaching at its middle. Area petiolaris large, hexagonal, as long as or slightly as long as wide. Hind femur 3.5 - 3.9 × as long as wide. Wing venation as in ♀. 1 st tergite 2.2 - 2.5 × as long as wide; petiole and postpetiole coarsely aciculate, striae almost appearing as dorso-lateral carinae. 2 nd tergite 0.8 - 1.0 × as long as wide. Thyridium large, transverse, on base of tergite. Stylet pointed apically, 1.6 - 1.7 × as long as 2 nd hind tarsomere. Color: face yellow; orbits cream-yellow; head otherwise yellowish-red. Mesosoma yellow; mesoscutum with brownish spots laterally and frontal-medially. Propodeum brown, apical 1 / 3 yellowish. 1 st tergite black, 1 st sternite sometimes rufous basally; 2 nd tergite brown, with yellow band in the apical 0.3 - 0.4; 3 rd tergite yellow, with apical brownish band; following tergites yellowish-brown and slightly vespoid. Legs yellow, hind tibia and hind tarsomeres slightly fuscous apically. Pterostigma hyaline. H o s t s: Catoptilia falconipennella (ÜBERNER, 1813) (Lep., Gracillariidae) (EDI), Pholesetor sp. (Hym. Braconidae) in Catoptilia rufipennella (ÜBERNER, 1813) (Lep., Gracillariidae) (EDI), Microgastrinae (Hym. Braconidae) in Ancylis upupana (TREITSCHKE, 1835) (Lep., Torticidae) (ZSM). R e m a r k s: The specimen reared from Ancylis upupana in the ZSM determined as “ macrocephalus ” and mentioned under this species in SCHWENKE (1999: 29) belongs to M. unicinctor. D i s t r i b u t i o n: Transpalaearctic; examined material from Austria, Azerbaijan *, Belgium, Byelorussia *, Germany, Russia (Murmansk region, Karelia, Tuva region, Far East Russia), Slovakia *, Sweden, and United Kingdom.	en	Riedel, Matthias (2025): Contribution to the knowledge of Palaearctic species of Mesochorus GRAVENHORST: Subgenus Stictopisthus THOMSON (Hymenoptera, Ichneumonidae, Mesochorinae). Linzer biologische Beiträge 56 (2): 669-710, DOI: 10.5281/zenodo.16956925
