Casinaria scalaris, Vas, 2019

Vas, Zoltán, 2019, Contributions to the taxonomy, identification, and biogeography of Casinaria Holmgren and Venturia Schrottky (Hymenoptera: Ichneumonidae: Campopleginae), Zootaxa 4664 (3), pp. 351-364 : 355-356

Casinaria scalaris sp. nov.

Material examined. Holotype: female, Mongolia, Chentej aimak, 15 km O von Öndörchaan, 1 km S vom Kerulen, 1000m, 30.VII.1965, leg. Z. Kaszab, Nr. 327; specimen pinned, Id. No. HNHM-HYM 153114 .— Paratype: male, Mongolia, Cojbalsan aimak, 44 km NW von Cojbalsan, 750m, 17.VIII.1965, leg. Z. Kaszab, Nr. 425; specimen pinned, Id. No. HNHM-HYM 153115 .— Paratype: male, Mongolia , Chövsgöl aimak, 10 km NO vom Fluss Delger mölön, 16 km N von Somon Burenchaan , 1700m, 17.VII.1968, leg. Z. Kaszab, Nr. 1118; specimen pinned, Id. No. HNHM-HYM 153116 .— The holotype and the paratype specimens are deposited in the Hymenoptera Collection of the HNHM (Budapest, Hungary) .

Diagnosis. Among the Palaearctic species of the genus C. scalaris sp. nov. is most similar in colouration and body proportions to C. subglabra Thomson , a Western Palaearctic species. The new species can be distinguished from C. subglabra by the following differences: longitudinal carinae of propodeum complete, strong, lateromedian longitudinal carinae relatively closely spaced, almost parallel to parallel along area basalis and area superomedia, relatively weakly divergent along area petiolaris; hypostomal carina elevated; malar space longer, 0.65× as long as basal width of mandible; apical reddish band of second tergite in dorsal view about as long medially as laterally, not arched medially toward base; hind tibia entirely dark brown in females; area superomedia distinctly longer than wide in both sexes; 2 m-cu reaching areolet distal to its middle in both sexes (while in C. subglabra only propodeal carinae enclosing area basalis and basal half of area superomedia developed; hypostomal carina not elevated; malar space shorter, 0.3× as long as basal width of mandible; apical reddish band of second tergite in dorsal view medially longer than laterally, distinctly arched medially toward base; hind tibia medially reddish in females; area superomedia about as long as wide in males; 2 m-cu reaching areolet at its middle in males).

Description. Female ( Figs 4–5 ). Body length ca 8 mm, fore wing length ca 4.5 mm.

Head: Antenna with 33 flagellomeres; basal flagellomeres relatively slender, first flagellomere ca 3× as long as wide apically; preapical flagellomeres slightly longer than wide. Head transverse, granulate with distinct, dense but superficial punctures, matt, and with dense, greyish hairs. Ocular-ocellar distance slightly shorter than ocellus diameter, posterior ocellar distance almost twice as long as ocellus diameter. Inner eye orbits relatively weakly indented and weakly convergent ventrally. Gena (temple) short, strongly narrowed behind eye, in dorsal view about 0.5× as long as eye width. Occipital carina complete, slightly bent outwards ventrally, reaching hypostomal carina little before mandibular base; hypostomal carina distinctly elevated, about as high as flange on lower margin of mandible. Malar space long, 0.65× as long as basal width of mandible. Face flat in profile, narrowed ventrally, minimal width of face 0.7× as long as eye length and 0.9× as long as width of frons. Clypeus flat, very weakly separated from face, weakly convex in profile, apical margin convex, sharp. Mandible short, high, lower margin of mandible with wide flange from teeth toward base, mandibular teeth of equal length.

Mesosoma: Mesosoma except propodeum granulate with distinct, dense punctures, propodeum rugose-punctate; mesosoma with dense, relatively short, greyish hairs. Pronotum with transverse wrinkles in ventral half; epomia strong. Mesoscutum convex in profile, about as long as wide, notaulus not developed. Scuto-scutellar groove deep. Scutellum convex in profile, lateral carina developed only at extreme basal part. Mesopleuron with relatively weak transverse wrinkles anterior to speculum; speculum granulate with weak transverse wrinkles, matt; mesopleural suture deep with strong transverse costae. Pleural part of epicnemial carina complete, 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) absent; ventral part of epicnemial carina (behind fore coxae) complete, not elevated. Sternaulus indistinct. Posterior transverse carina of mesosternum complete. Metanotum short, less than 0.5× as long as scutellum. Metapleuron without juxtacoxal carina; submetapleural carina complete, strong. Pleural carina of propodeum strong; propodeal spiracle elliptic, separated from pleural carina by less than its length, connected to pleural carina by a short, indistinct ridge. Propodeum rugosepunctate to coarsely rugose, its apex not reaching middle length of hind coxa. Lateral and lateromedian longitudinal propodeal carinae complete and rather strongly developed, transverse carinae missing except apical border of area basalis; lateromedian longitudinal carinae relatively closely spaced, almost parallel to parallel along area basalis and area superomedia, relatively weakly divergent along area petiolaris. Area basalis rectangular, about 0.6× as long as its apical width, only slightly narrower than area superomedia. Area superomedia narrow, long, distinctly longer than wide, covered with transverse wrinkles and transverse rugosity, confluent with area petiolaris. Area petiolaris widely but shallowly impressed with transverse wrinkles all along the impression. Fore wing with relatively small, petiolate areolet, second recurrent vein (2 m-cu) distal to its middle, 3 rs-m weakly pigmented; distal abscissa of Rs straight; nervulus (cu-a) interstitial; postnervulus (abscissa of Cu 1 between 1 m-cu and Cu 1a + Cu 1b) intercepted below middle by Cu 1a; lower external angle of second discal cell right-angled. Pterostigma long and narrow. Hind wing with nervellus (cu-a + abscissa of Cu 1 between M and cu-a) intercepted at its lower third, anterior to interception vertical, posterior to interception reclivous; discoidella (distal abscissa of Cu 1) connected to nervellus, spectral. Coxae finely granulate with dense, weak, superficial punctures. Hind femur 4.5× as long as high. Inner spur of hind tibia about 0.65× as long as first tarsomere of hind tarsus. Tarsal claws small and short, little longer than arolium, with 2–3 basal pecten.

Metasoma: Metasoma finely granulose and weakly, superficially punctate with short greyish hairs. First tergite short, stout, strongly widened apically, 2.2× as long as its apical width, 1.4× as long as second tergite, distinctly shorter than hind femur, without glymma; dorsomedian carina of first tergite indistinct; petiolus shorter than postpetiolus, basally depressed, about 2× as long as high. Suture separating first tergite from first sternite situated little above mid-height at basal third of first metasomal segment. Second tergite stout, 0.9× as long as its apical width; thyridium short oval, its distance from basal margin of tergite less than its length. Third tergite 0.65× as long as its apical width, following tergites all wider than long, medially not excised. Ovipositor sheath short, barely extending metasomal apex.

Colour: Antenna blackish to very dark brown. Head black except palpi brown and mandibular teeth dark reddish brown. Mesosoma (including tegula) black. Metasoma: first tergite black, second tergite black with apical third reddish (apical reddish band in dorsal view about as long medially as laterally, its base not arched), third tergite entirely reddish, fourth tergite almost entirely reddish, fifth and following tergites black; ovipositor sheath dark brown. Wings hyaline, wing veins and pterostigma brown. Fore leg: coxa black; trochanter black; trochantellus predominantly dark brown; femur reddish brown, basally darkened; tibia brownish red; tarsus brownish. Middle leg: coxa, trochanter and trochantellus black; femur blackish to dark brown, apically narrowly yellowish brown; tibia brownish; tarsus brownish. Hind leg: coxa, trochanter and trochantellus black; femur black; tibia entirely dark brown; tarsus dark brown without yellowish base on first tarsomere.

Male ( Fig. 6 ): Body length ca 7–8 mm, fore wing length ca 4.5–5 mm. Similar to female in all characters described above, except: antenna with 32–33 flagellomeres; gena (temple) 0.5–0.6× as long as eye width; malar space 0.7–0.8× as long as basal width of mandible; speculum very finely granulate to smooth; hind femur 4.5–5× as long as high; inner spur of hind tibia about 0.6× as long as first tarsomere of hind tarsus; first tergite ca 2.5× as long as its apical width; second tergite as long as its apical width; clasper dark brown, elongate; apical reddish band of second tergite shorter; third tergite entirely reddish to almost entirely reddish; fourth tergite almost entirely reddish to reddish brown; fore and middle tibia externo-medially more yellowish; fore and middle tarsus yellowish to brownish; hind tibia dark brown with yellowish stripe externo-medially; hind tarsus dark brown with very narrow yellowish base on first tarsomere.

Distribution. Currently known from Mongolia.

Ecology. No host is known. Most probably a koinobiont endoparasitoid of lepidopterous hosts as other Casinaria species.

Etymology. The specific epithet scalaris is the feminine form of the Latin adjective scalaris , -is, -e meaning resembling a ladder; it refers to the ladder-shaped structure of propodeal carination and sculpture (composed by the complete, relatively closely spaced, parallel to weakly divergent lateromedian longitudinal carinae and the transverse wrinkles between them).

Remarks. By using the identification key of the most recent revision of Western Palaearctic Casinaria species ( Riedel 2018), C. scalaris sp. nov. keys out together with C. subglabra at couplet 28. The distinctive characteristics from this species are given in the Diagnosis section.

Figures

FIGURES 4–6. Casinaria scalaris sp. nov.: 4, female, holotype; 5, propodeal carination from dorsal view (only carinae are depicted, surface structures such as rugosity, punctures and wrinkles are not illustrated); 6, male, paratype.