Mesochorus ( Stictopisthus ) longistylus, Riedel, 2025

Mesochorus ( Stictopisthus) longistylus nov.sp. (figs 18, 29, 37, 60, 80)

H o l o t y p e: (Ô) “ Lazio, RM. Anticoli, Corrado, 325 m, 14.V.2011, leg. M. Mei, G. Lo Giudice” (ZSM).

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 2m-cu reaching slightly proximad its middle. Vein 1cu-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 2m-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.

Mesochorus ( Stictopisthus) macrocephalus STROBL, 1904 (figs 6, 21, 30, 43, 61, 73, 83) O r i g i n a l: Mesochorus ( Stictopisthus) macrocephalus STROBL, 1904: 106 , ³.

H o l o t y p e: (³) “Styriae alp. Strobl” (Admont), type examined.

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 2m-cu reaching slightly proximad its middle. Vein 1cu-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 2m-cu reaching slightly proximad its middle; vein 1cu-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.