Mesochorus ( Stictopisthus ) ranini VIKBERG , 2017

Mesochorus ( Stictopisthus) ranini VIKBERG, 2017 (figs 14, 17, 36, 51, 70, 78, 84)

H o l o t y p e: ( ♀) “Fennia Li Utsjoki KK 18.6.1960, leg. V. Vikberg” (Helsinki), type examined.

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; 1st 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 2m-cu reaching at its middle. Vein 1cu-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 2m-cu reaching proximad its middle. Vein 1cu-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*.