Mesochorus lapponicus

Riedel, Ravenhorst Matthias, 2018, Contribution to the Palaearctic species of Mesochorus G (Hymenoptera, Ichneumonidae, Mesochorinae): 1. The M. fulvus-group, Linzer biologische Beiträge 50 (1), pp. 687-716 : 697-698

Mesochorus lapponicus THOMSON, 1885: 336 ( figs 52-55 )

Lectotypus: (♀) Lap; lapponicus (Lund) , type studied.

Description: ♀: Bodylength 6.5-8 mm. Flagellawith 42-46 segments; 1 st flagellomeres length 6.5x width and 0.64x eye length; 2 nd flagellomeres length 4x width; preapical flagellomeres c.2x longer than wide. Temples strongly narrowed behind eyes, length 0.5x eye width. OOD 0.7-1.0. Face width 1.05x length of clypeus+face and 0.8- 0.9x eye length, punctate, with parallel or slightly convergent sides ventrally. Clypeus

with scattered punctures. MI 0.25-0.3. Mandibles with two equal teeth. Malar spaces, mandibular bases and ventral 0.3 of facial orbits striate. Occipital carina complete medially. Genal carinae reach the hypostomal ones far from mandibular bases, hypostomal carina slightly elevated. Pronotum largely smooth; mesoscutum with dense and coarse punctures caudal-medially and with dense but finer punctures laterally; mesopleura with dense fine punctures dorsally and moderately dense to scattered punctures ventrally; metapleura with fine scattered punctures. Area basalis trapezoid or rectangular, length 1.7-2x width; area superomedia length 2.1-2.3x width and 2.2x length of area petiolaris, costulae in frontal 0.3-0.4; area petiolaris about as long as wide. Hind femora length 5.1-5.3x height; hind metatarsi length 0.46x length of hind tibiae; hind claws with 3-4 short basal teeth; length of distal fore tarsomeres c.2.6-2.7x width. Areolets pointed-sessile, oblique; 2 nd recurrent veins in or slightly proximal to their middle; nervuli interstitial; postnervuli intercepted at basal 0.2; pterostigma length 3.0x width, radial veins in their distal 0.7. 1 st tergite length 3.2-3.6x width; postpetiole smooth, length 1.7x width; 2 nd tergite length 1.05-1.25x width; thyridia transversal-oval. Ovipositor sheaths length 6.8-8.0x height and 0.72-0.76x length of hind metatarsi, slightly narrowed in apical half.

Colour: Reddish including ocellar space and ovipositor sheaths. Palps, mandibles except teeth, malar spaces, inner orbits, hind edges of pronotum, tegulae, wing bases, fore and middle coxae and trochanters completely and fore and middle femora frontally yellowish. Pterostigmata brown, paler proximally and distally. Ovipositor sheaths yellowish.

♂: Claspers pointed apically, length 1.4x length of 2 nd hind tarsomeres.

Hosts unknown.

Distribution: Norway, Russia (Karelia), Sweden.

Figures

Figs 52-55: Mesochorus lapponicus THOMSON ♀: (52) face of lectotype, (53) propodeum of lectotype, (54) ovipositor sheaths, (55) clasper (♂).