A new species of Poemenia Holmgren with a key to species known from China and the Eastern Palaearctic Region (Hymenoptera, Ichneumonidae, Poemeniinae)

Abstract A new species of Poemeniinae, Poemenia quercusia Sun & Sheng, sp. n., is described and illustrated. Specimens were reared from twigs of Quercus wutaishanica Blume in Haicheng, Liaoning province, P.R. China. A key to species known from China and the Eastern Palaearctic Region is provided.

In the last two years the authors have been exploring mountains in Haicheng, Liaoning Province, situated near the southern border of the Eastern Palaearctic part of China, and gathered many wood and tree branches infested by woodborers, and have collected large numbers of ichneumonids. In this article a new species of Poemenia is described. The species was reared from twigs of Quercus wutaishanica Blume.
The type locality is a forest comprised of mixed deciduous angiosperms and evergreen conifers, mainly including Quercus wutaishanica, Quercus sp., Larix sp., Castanea spp. and Pinus tabulaeformis Carr.

Material and methods
Rearing parasitoids. Trunks and twigs of naturally infested Q. wutaishanica trees were brought to the laboratory and maintained in a large nylon cage at room temperature. Water was sprayed over the trunks and twigs twice a week and emerged insects collected daily.
Type specimens are deposited in the Insect Museum, General Station of Forest Pest Management (GSFPM), State Forestry Administration, People's Republic of China.

Diagnosis.
Interior margins of eyes ventrally subparallel. Clypeus approximately 2.0 times as wide as long, evenly convex. Mandible with two teeth, lower tooth rather elongate. Upper portion of gena not or finely sculptured. Mesoscutum without transverse wrinkles or with fine wrinkles associated with notauli. Epicnemial carina absent. Areolet present or absent. Hind wing vein 1-cu distinctly shorter than cu-a. Claw simple. Second tergite without anterolateral grooves. Diagnosis. Face (Fig. 8) with dense long opalescent hairs. Hind wing vein 1-cu almost vertical, nearly 0.3 times as long as cu-a; cu-a strongly reclivous. Propodeum (Fig. 11) evenly longitudinally convex, without carinae, with dense opalescent hairs. Propodeal spiracle circular. First sternite extending to 0.5 length of tergite. Second tergite approximately 1.5 times as long as apical width. Hind coxa and femur red brown, basal portions of tarsomeres 1 to 4 white.

Key to species of Poemenia from China and the Eastern Palaearctic Region
Description. Female. Body length approximately 8.5 mm. Fore wing length approximately 5.5 mm. Ovipositor sheath length approximately 4.5mm.
Head. Inner margins of eyes slightly convergent ventrally. Face (Fig. 8) with dense long opalescent hairs; upper margin with a small median tubercle. Clypeus 2 times as wide as long, with dense fine punctures; apical margin slightly concave, with dense light brown hairs. Mandible with dense fine punctures. Malar space approximately 0.2 times as long as basal width of mandible. Gena in lateral view 0.5 times as long as width of eye, with even, fine punctures. Vertex (Fig. 9)   cal, approximately 0.3 times as long as cu-a; cu-a strongly reclivous. Ratio of length of hind tarsomeres 1:2:3:4:5 is 10.0:4.0:2.6:1.7:2.0. Propodeum (Fig. 11) evenly longitudinally convex, without carinae, with dense opalescent hairs; apical-median portion with indistinct transverse rugae. Propodeal spiracle circular.
Metasoma. First tergite (Figs 6, 12) approximately 2.7 times as long as apical width, 1.3 times as long as second tergite (Fig. 13), subcylindrical; with dense indistinct punctures and shallow median longitudinal groove; spiracle located at basal 0.38 of first tergite. First sternite extending to 0.5 length of tergite. Tergites 2 to 6 with dense punctures. Second tergite approximately 1.5 times as long as apical width. Tergites 3 to 6 parallel-sided. Third tergite approximately 1.4 times as long as apical width. Ovipositor sheath 0.88 times as long as fore wing, 0.9 times as length of metasoma.
Color (Fig. 7). Black, except following. Maxillary and labial palpi, ventral profiles of scape and pedicel, anterior margin of pronotum, tegula, fore and mid coxae and trochanters white. Basal-dorsal profile of flagellum slightly yellowish brown. Fore and mid legs yellowish white, dorsal profiles slightly yellowish brown. Tarsomeres 4 and 5 of fore tarsus dark brown. Apical portion of tarsomeres 1 to 3, and entire 4 and 5 of mid tarsus brownish black. Hind coxa and femur red brown. Apex of hind femur black. Apex of hind coxa and trochantellus mainly, basal end of femur, basal portions of tibia, basal halves of tarsomeres 1 to 3 and base of tarsomere 4 white. Pterostigma and veins brown.
Host. Unknown, but reared from twigs of Quercus wutaishanica Blume. Many specimens of Carcilia sp. (Coleoptera: Curculionidae) were also reared from these twigs. But confirmed hosts of Poemenia are solitary aculeate wasps such as Passaloecus species (Hymenoptera: Crabronidae) (e.g. Shaw 2006) and it is possible that the hosts of P. quercusia sp. n. were nesting in beetle burrows in these twigs.
Remarks. This new species is similar to P. taiwana Sonan, 1936, but can be distinguished from the latter by the following combinations of characters: apical margin of clypeus evenly concave, with dense light brown hairs; first tergite approximately 2.7 times as long as apical width; third tergite distinctly shorter than second tergite; hind coxa reddish brown; basal halves of tarsomeres 1 to 3 and base of tarsomere 4 white. Poemenia taiwana: apical margin of clypeus rounded, without dense light brown hairs; first tergite nearly 3.0 times as long as apical width; third tergite as long as second tergite; hind coxa with only ventral profile reddish-brown; tarsomeres entirely black. They can be distinguished by the key provided above.