Trieces etuokensis Sheng

Zhang, Ying, Sheng, Mao-Ling & Xiong, Zi-Cheng, 2016, A new species of Metopiinae (Hymenoptera, Ichneumonidae) parasitizing lepidopteran larvae in China, ZooKeys 572, pp. 71-79 : 74-77

Taxon classification Animalia Hymenoptera Ichneumonidae

Trieces etuokensis Sheng sp. n. Figs 3-5, 6-12

Etymology.

The specific name is derived from the holotype locality.

Material examined.

Holotype female reared from pupa of unidentified psychid moth on 27 October 2014, CHINA: Mukainor, 1476m, Etuoke, Inner Mongolia Autonomous Region, Mao-Ling Sheng. Paratypes: 1 male, same data as holotype except 24 October 2014. 1 female reared from pupa of Bazaria turensis (Ragonot, 1887) on 2 October 2013, China: Balong, 2857m, Dulan, Qinghai Province, Mao-Ling Sheng.

Diagnosis.

Malar space approximately as long as basal width of mandible. Ocular-ocellar line as long as diameter of posterior ocellus. Antenna slightly longer than head and mesosoma combined, with 17 flagellomeres. Occipital carina entirely absent. Metapleuron shiny, impunctate, lower posterior portion with distinct wrinkles. Hind femur compressed, 2.5 × as long as maximum width. Face and clypeus yellow. Fore and middle femora and hind tibia mainly black.

Description.

Female. Body length approximately 2.8 mm. Fore wing length approximately 2.2 mm.

Head. Inner margins of eyes distinctly convergent downwards. Face (Fig. 4) with dense fine punctures, distance between punctures 0.2 –0.5× diameter of puncture. Clypeus with denser punctures than that of face, distance between punctures approximately 0.2 × diameter of puncture, apical portion slightly concave; apical margin almost truncate. Mandible small, weakly narrowed toward apex; upper tooth distinctly longer than lower tooth. Malar area flat, with fine punctures. Malar space approximately as long as basal width of mandible. Gena in dorsal view approximately as long as width of eye, almost smooth, with sparse, indistinct fine punctures, scarcely convergent posteriorly. Vertex (Fig. 5) and frons almost shiny, with indistinct fine punctures. Postocellar line 1.2 × as long as ocular-ocellar line. Ocular-ocellar line approximately as long as diameter of posterior ocellus. Upper portion of frons slightly convex, lower portion slightly concave. Antenna (Fig. 6) slightly longer than head and mesosoma combined, with 17 flagellomeres; each flagellomere longer than wide. First flagellomere 2.2 × as long as maximum width, 1.1 × as long as third flagellomere. Occipital carina absent.

Mesosoma. Lateral concavity of pronotum smooth, shiny, upper-posterior portion slightly rough, with dense shallow fine punctures. Epomia indistinct. Mesoscutum (Fig. 7) smooth, shiny, anterior portion slightly convex, posterior flat; with dense distinct punctures, distance between punctures 0.2 –2.0× their diameter. Notaulus absent. Scutellum almost flat, shiny, with sparse, indistinct, fine punctures; lateral carina reaching apex. Postscutellum so short it resembles a transverse carina. Mesopleuron (Fig. 8) with sparse fine punctures. Speculum with fine indistinct punctures. Mesopleural fovea vestigial. Upper end of epicnemial carina reaching anterior margin of mesopleuron, at dorsal 0.75 of posterior margin of pronotum. Metapleuron almost flat, shiny, postero-dorsal portion with few hairs, lower posterior portion with distinct wrinkles. Juxtacoxal carina strong. Wings (Fig. 9) slightly infuscate. Fore wing with vein 1cu-a strongly inclivous, distal to 1-M by about 0.4 × length of 1cu-a. 2m-cu straight, distinctly inclivous, distal to 2rs-m by about 1.4 × length of 2rs-m. Hind wing vein 1-cu 2.0 × as long as cu-a. Hind femur compressed, 2.5 × as long as maximum width. Hind tibia gradually widened apically. Posterior spur of hind tibia approximately 2.75 × as long as anterior spur. Ratio of length of hind tarsomeres 1:2:3:4:5 is 2.8:1.2:1.0:0.8:1.6. Propodeum (Fig. 10) with strong apical transverse and complete longitudinal carinae. Pleural areas with dense, distinct, fine punctures. Area petiolaris with longitudinal wrinkles. Remainder of propodeum smooth, shiny, with indistinct fine punctures. Propodeal spiracle small, circular.

Metasoma (Figs 11, 12). First tergite approximately 0.75 × as long as apical width, with dense punctures; median dorsal, dorsolateral, ventrolateral and sublateral longitudinal carinae complete; apical half with distinct median longitudinal carina. Second tergite (Fig. 11) 1.27 × as long as apical width, densely punctate, median and sublateral carinae complete. Third tergite 0.78 × as long as apical width; basal 0.7 with dense punctures, apical 0.3 with sparser punctures and smoother than basal 0.7; basal 0.4 with median longitudinal carina; basal 0.3 with lateral longitudinal carinae. Basal 0.6 of fourth tergite densely punctate, apical 0.4 shiny, gradually impunctate. Basal 0.4 of fifth tergite with dense punctures, apical 0.6 gradually impunctate. Ovipositor (Fig. 12) tapered from base to apex, with a large, shallow notch.

Color (Fig. 3). Black, except as follows. Face (Fig. 4) except upper median light brown spot, malar area and clypeus yellow. Maxillary and labial palpi yellow brown. Anterior profile of pedicel dark brown; basal ventral profile of antenna red-brown, basal dorsal profile darkish brown; apical portion brownish black. Anterior and posterior profiles of fore femur, tibia and tarsus, basal and apical portions of mid tibia, mid tarsus, all trochanters more or less, tegula brown to dark brown. Pterostigma (Fig. 9) blackish. Wing veins dark brown.

Male. Body length approximately 3.1 mm. Fore wing length approximately 2.5 mm. Antenna with 22 flagellomeres. Very similar to the female, except with hind first tarsomere yellow, apical portion pale brown yellow.

Hosts.

One female was reared from pupa of Bazaria turensis (Ragonot, 1887) ( Lepidoptera : Pyralidae ). One female and one male were reared from unidentified species of Psychidae ( Lepidoptera ) collected as mature larvae but details of development and emergence unknown.

Host plants.

Caragana intermedia Kuang & H.C. Fu ( Leguminosae ), Nitraria tangutorum Bobrov ( Zygophyllaceae ), Kalidium foliatum (Pallas) Moquin-Tandon ( Amaranthaceae ).

Remarks.

This new species is similar to Trieces pumicatus Tolkanitz, 2010 and can be distinguished from the latter by the following combination of characters: antenna slightly longer than head and mesosoma combined, with 17 flagellomeres (female); fore wing with vein 1cu-a distinctly distal of 1-M, distance between them 0.4 × length of 1cu-a; hind femur compressed, 2.5 × as long as maximum width; lateral longitudinal carinae of tergite 3 distinct on anterior 0.3; fore and middle femora, hind tibia mainly black; basal ventral profile of antennae red brown, basal dorsal profile darkish brown; apical portion brownish black. The same characters for Trieces pumicatus Tolkanitz are as follows: antenna not longer than head and mesosoma combined, with 20 flagellomeres (female); fore wing with vein 1cu-a slightly distal of 1-M, nearly interstitial; length of hind femur 2.2 × its width; lateral longitudinal carinae of tergite 3 vanishing behind its middle; fore and mid legs, hind tibia reddish yellow, fore and mid femora slightly darkened on outer side; antenna reddish yellow.