Nemeritis legasovi, Vas, 2020

Vas, Zoltán, 2020, Contributions to the taxonomy and biogeography of Nemeritis Holmgren (Hymenoptera: Ichneumonidae: Campopleginae), Zootaxa 4758 (3), pp. 486-500 : 495-496

Nemeritis legasovi sp. nov.

Material examined. Holotype: female, Mongolia, Bajan-Ölgij aimak, in Tal des Flusses Chavcalyn gol, 25 km O von Somon Cagannuur, 1850m, 3.VII.1968, leg. Z. Kaszab (Nr. 1056); specimen pinned, Id. No. HNHM-HYM 153206 .— Paratypes: three females and one male, same locality and collecting data as holotype; specimens pinned, Id. No. HNHM-HYM 153207–153210 , respectively.—The holotype and paratype specimens are deposited in the Hymenoptera Collection of HNHM (Budapest, Hungary) .

Diagnosis. Nemeritis legasovi sp. nov. can be identified by the combined presence of the following characteristics: second flagellomere ca 3.0× as long as wide apically; gena in dorsal view 0.65–0.7× as long as eye width, moderately narrowed behind eye; face slightly narrower than width of frons below median ocellus; clypeus granulate, matt, with few indistinct punctures, its apical margin weakly convex, medially almost straight, sharp, medially smooth and shiny; mandibular teeth of equal length; mesosoma not elongate; propodeal carinae well developed; area basalis trapezoidal, almost as long as its basal width; area superomedia granulate, not conspicuously shiny, with weak diagonal wrinkles along its lateral margins and with distinct diagonal wrinkles apically, little longer than wide, almost flat to slightly impressed, its lateral carinae parallel behind costulae, apically opened, confluent with area petiolaris, little shorter than area petiolaris; area petiolaris granulate with distinct, laterally diagonal, medially almost transverse wrinkles, little impressed, lying in the same level with area superomedia; fore wing with areolet; second tergite 1.2–1.4× as long as its apical width; ovipositor sheath ca 2.4–2.5× as long as hind tibia; scapus dark brown, ventrally yellowish brown; tegula yellow; second tergite in female black to dark brown with a relatively wide apical reddish band occupying posterior 0.15–0.2× tergite length, in male reddish with a pair of subapical blackish patches; third tergite dark brown to black; hind femur reddish brown to chestnut brown, basally little darkened; hind tibia basally and externo-medially yellowish brown, subbasally and apically darker brown. Nemeritis legasovi sp. nov. is similar to N. elegans (Szépligeti) , which species can be distinguished from the new species by its longer ovipositor sheath (ca 2.8× as long as hind tibia), area superomedia (about as long as wide, its lateral carinae slightly converging behind costulae), shorter and more strongly narrowed gena (in dorsal view 0.5–0.55× as long as eye width), more elongate second tergite (about 1.5× as long as its apical width), and by distinctly lighter coloured hind femur and tibia. The new species is also similar to N. caudata (Szépligeti) , which species can be readily distinguished from the new species by its area superomedia (conspicuously shiny, very finely sculptured, its lateral carinae weakly but distinctly converging behind costulae), shorter and more strongly narrowed gena (in dorsal view 0.5–0.55× as long as eye width), and in female by its distinctly narrower (at most 0.1× tergite length), yellowish apical band of second tergite.

Description. Female ( Figs 13–16 ). Body length ca 5.0–6.0 mm, fore wing length ca 4.0 mm.

Head: Antenna with 28–30 flagellomeres; basal flagellomeres slender, first flagellomere ca 4.0–5.0× as long as wide apically; second flagellomere ca 3.0× as long as wide apically; preapical flagellomeres slightly longer than wide. Head granulate with some very weak, inconspicuous, superficial punctures and with dense, greyish hairs, transverse, moderate sized, ca 1.4–1.5× as wide as maximum width of mesoscutum. Ocelli small, ocular-ocellar distance 1.6–1.8× as long as ocellus diameter, posterior ocellar distance 1.4–1.8× as long as ocellus diameter. Inner eye orbits almost parallel, inconspicuously convergent ventrally, not indented. Frons little impressed above toruli. Gena (temple) moderately long, in dorsal view 0.65–0.7× as long as eye width, moderately narrowed behind eye. Occipital carina complete, reaching hypostomal carina little but distinctly behind mandibular base; hypostomal carina not elevated. Malar space 0.6–0.7× as long as basal width of mandible. Face about flat in profile, slightly narrower than width of frons below median ocellus. Clypeus flat, wide, very weakly separated from face, granulate, matt, with few indistinct punctures; apical margin of clypeus weakly convex, medially almost straight, sharp, medially smooth and shiny. Mandible relatively long, lower margin of mandible with relatively low carina from teeth toward base, mandibular teeth of equal length.

Mesosoma: Mesosoma granulate with relatively dense weak, superficial punctures and with dense, short greyish hairs, not elongate, ca 2.2–2.4× as long as wide. Pronotum with transverse wrinkles in ventral two-third and along anterior side; epomia distinct. Mesoscutum convex in profile, about as long as wide, notaulus not developed. Scuto-scutellar groove wide, moderately deep. Scutellum convex in profile, without lateral carina. Mesopleuron granulate, matt; speculum largely smooth and shiny; mesopleural suture with weak transverse costae. Pleural part of epicnemial carina strong, bent to anterior margin of mesopleuron reaching it below its middle height; transversal part of epicnemial carina (i.e. part at the level of sternaulus running through the epicnemium to the ventral edge of pronotum) not developed; ventral part of epicnemial carina (behind fore coxae) strong, not elevated. Sternaulus indistinct. Posterior transverse carina of mesosternum complete. Metanotum 0.4–0.5× as long as scutellum. Metapleuron granulate; basal part of juxtacoxal carina rather weak but more or less discernible; submetapleural carina complete. Pleural carina of propodeum complete; propodeal spiracle small, circular, separated from pleural carina by about its length, connected to pleural carina by a weak ridge. Propodeum granulate; propodeal carinae well developed, costulae complete, sometimes little weakened. Area basalis trapezoidal, almost as long as its basal width. Area superomedia granulate, matt, not conspicuously shiny, with weak diagonal wrinkles along its lateral margins and with distinct diagonal wrinkles apically, hexagonal, almost flat to slightly impressed, little longer than wide, its lateral carinae parallel behind costulae, apically opened, confluent with area petiolaris, little shorter than area petiolaris, costulae connected to lateral margins of area superomedia at or little above its middle. Area petiolaris granulate with distinct, laterally diagonal, medially almost transverse wrinkles, little impressed, lying in the same level with area superomedia. Fore wing with relatively large, subsessile or short-stalked areolet, second recurrent vein (2 m-cu) strongly distal to its middle, 3 rs-m pigmented; distal abscissa of Rs straight, its distal part slightly curved toward anterior wing margin; distal abscissa of M weakly pigmented; nervulus (cu-a) interstitial, inclivous; postnervulus (abscissa of Cu 1 between 1 m-cu and Cu 1a + Cu 1b) intercepted at or slightly above middle by Cu 1a; lower external angle of second discal cell about right-angled or nearly so. Hind wing with nervellus (cu-a + abscissa of Cu 1 between M and cu-a) broken and intercepted by discoidella (distal abscissa of Cu 1) at about anterior 0.6× its length, anterior section about vertical, posterior section reclivous; discoidella spectral, connected to nervellus. Coxae granulate. Hind femur ca 4.5× as long as high. Inner spur of hind tibia about 0.4–0.5× as long as first tarsomere of hind tarsus. Tarsal claws small and thin, little longer than arolium, with few indistinct basal pecten.

Metasoma: Metasoma finely granulate to shagreened with moderately dense greyish hairs. First tergite relatively stout, ca 2.3–2.5× as long as its apical width, ca 1.0–1.1× as long as second tergite, without glymma; dorsomedian carina of first tergite basally distinct. Second tergite 1.2–1.4× as long as its apical width; thyridium short oval, very weak, its distance from basal margin of tergite about 1.5–2.0× as long as its length. Third tergite ca 0.85× as long as its apical width. Metasoma from third tergite onward weakly compressed, posterior margin of apical tergites medially very weakly, shallowly excised. Ovipositor sheath long, ca 2.4–2.5× as long as hind tibia; ovipositor thin, compressed, subapically slightly swollen.

Colour: Antenna dark brown, scapus ventrally and pedicellus apically yellowish brown. Head black, palpi yellowish, mandible yellow except dark reddish brown teeth. Mesosoma black except tegula yellow. Metasoma: first tergite black with a very narrow pale apical band; second tergite black to dark brown with a relatively wide apical reddish band occupying posterior 0.15–0.2× tergite length; third tergite dark brown to black; following tergites black with a very narrow, inconspicuous pale apical band on each tergite; ovipositor sheath dark brown. Wings hyaline, wing veins brown, pterostigma brown, medially yellowish brown. Fore and middle legs: coxae black; trochanters dorsally and apically yellow, ventrally extensively reddish or brownish; trochantelli yellow; femora reddish; tibiae reddish, basally and externally somewhat lighter, yellowish; tarsi reddish to brownish. Hind leg: coxa black; trochanter black, apically narrowly reddish brown; trochantellus brownish, ventrally and apically yellowish; femur reddish brown to chestnut brown, basally little darkened; tibia brownish, basally and externo-medially somewhat lighter yellowish brown, subbasally and apically darker brown; tarsus brownish, extreme base of first tarsomere weakly and narrowly yellowish brown.

Male: Similar to female in all characters described above, except: head ca 1.3× as wide as maximum width of mesoscutum; first tergite little slenderer, ca 2.7× as long as its apical width, ca 1.2× as long as second tergite; third tergite about as long as its apical width; posterior margin of apical tergites not excised; second tergite reddish with a pair of blackish patches on its posterior half, blackish patches starting at about 0.6× tergite length and extending to about 0.75× tergite length, medially not touching each other; fore and middle coxae predominantly yellow, basally blackish, trochanters and trochantelli yellow; hind trochantellus yellow; basal and externo-medial yellowish brown colouration of hind tibia little lighter yellowish brown than in female.

Distribution. Currently known from Mongolia.

Ecology. No host is known.

Etymology. The new species is dedicated to Valerij A. Legasov for his key role in reducing the effects of the nuclear disaster of Chernobyl, saving the life and health of millions of people in Europe, and for his commitment to honesty regarding the management and investigation of the disaster.

Remarks. The new species belongs to the N. elegans species group sensu Horstmann (1975, 1994). It can be distinguished from all species of the group by the combined presence of the characters given in the Diagnosis section. Species of this group are known to be parasitoids of Raphidiidae (Raphidioptera) .

Figures

FIGURES 13–16. Nemeritis legasovi sp. nov., holotype female: 13, lateral habitus; 14, head in dorsal view; 15, propodeum in dorsal view; 16, colouration of basal tergites.