A new species of Pseudomegischus van Achterberg from China, with a key to the species (Hymenoptera, Stephanidae)

Abstract The genus Pseudomegischus van Achterberg, 2002, is newly reported from China. A new species, Pseudomegischus notiochinensis sp. n., is described and illustrated from southern China. A key to the species of Pseudomegischus is included.


Introduction
The small genus Pseudomegischus van Achterberg, 2002 (Hymenoptera: Stephanidae) has an Indo-Australian distribution and contains four described species. The species were revised by van Achterberg (2002) and the nearest known locality of the genus (compared to China) is the southern Philippine island of Mindanao. Recently, one of us (TL) reared a series obviously belonging to a new species of Pseudomegischus. It is the first host record of a species of this genus and the first species known from the Asian continent. There are several host records of Stephanidae, mainly of the genus Foenatopus Smith, 1860 (Aguiar 2004, Aguiar et al. 2010) and mainly concerning Buprestidae and Cerambycidae (Coleoptera). In China Stephanidae has been reported from Buprestidae by Chao (1964) (Megischus ptosimae Chao, 1964, reared from Ptosima chinensis Marseul, 1867 in peach trees) and Tan et al. (2015) (Schlettererius determinatoris Madl, 1991, reared from Chrysobothris succedana (Saunders) in Larix sp.). Van Achterberg and Yang (2004) reported ovipositing in Buprestid and Cerambycid larvae in various trees by Megischus tridentatus van Achterberg & Yang, 2004. The only case of biological control involving Stephanidae is the Nearctic Schlettererius cinctipes (Cresson, 1880) introduced to Tasmania from California for control of the introduced Sirex noctilio (Fabricius, 1793) (Hymenoptera: Siricidae ;Taylor 1967;van Achterberg 2002).

Material and methods
The specimens studied of Pseudomegischus spp. belong to the collection of the Insect Museum of the General Station of Forest Pest Management, Shenyang (GSFPM), P.R. China, some paratypes are deposited in the insect collection of the Northwest University, Xi'an (NWUX), P.R. China, and the Naturalis Biodiversity Center, Leiden (RMNH), the Netherlands.
The morphological terminology follows van Achterberg (2002) and a key to the genera is present in this paper and in Hong et al. (2011). Observations and descriptions were made with an Olympus SZX11 stereomicroscope and fluorescent lamps. Photographic images were made with the Keyence VHX-5000 digital microscope and processed with Adobe Photoshop CS5. Diagnosis. Temple with pale yellowish streak (Fig. 5); vertex anteriorly and stemmaticum (= ocellar area) with shallow median groove (Figs 10-11); pronotum with weak or strong transverse protuberance (Fig. 3); neck with two strong converging carinae laterally and antero-medially with triangular protuberance (Fig. 6); vein 1-M of fore wing 3.1-4.8 × vein 1-SR; vein 1-SR of fore wing straight (Fig. 4); hind tibia with small round pit at top of depression; outer side of hind tibia with oblique striae or carinae (Fig. 7); hind femur with two large teeth (Fig. 7); pygidial process in both sexes present (Fig. 13); ovipositor sheath without ivory subapical band (Fig. 1).

Key to species of the genus
The new species runs to P. celebensis van Achterberg in the key in van Achterberg (2002), but differs by having the head mainly dark brown (much paler in P. celebensis), the propodeum regularly scrobiculate (partly rugose), the mesopleuron with large smooth interspaces between medium-sized to small punctures (with larger punctures and narrower interspaces) and the ivory streak of the temple distinct (obsolescent).
Description. Holotype, female, length of body 16.7 mm, and of fore wing 8.9 mm. Head. Antenna with 39 segments; frons coarsely obliquely rugose; three anterior coronal teeth large and acute, both posterior ones arcuate and lamelliform, with two small lobe-shaped carinae on each side in front of both posterior ocelli; behind level of coronal area having four curved, progressively smaller carinae followed by rugose area, rugae rather coarse, posteriorly narrowly reaching occipital carina and widely smooth laterally; temple non-angulate (Fig. 10), punctulate but largely smooth and shiny.
Mesosoma. Neck short and robust, transversely rugose, neck at much lower level than middle part of pronotum (Figs 5, 6); middle part of pronotum largely smooth and without a distinct carina posteriorly; propleuron with sparse large punctures, shiny and rather densely setose; mesonotum irregularly foveolate and area between smooth; notauli and median groove distinct; scutellum with some coarse punctures medially, foveolate laterally; axillae coarsely punctate; mesopleuron distinctly convex, convex part foveolate-punctate and covered with long whitish setae, medially convex part of metapleuron rugose and with long whitish setae, anteriorly crenulate and intermediate area smooth; propodeum densely irregularly rugose (Fig. 6).
Wings. Fore wing (Fig. 4): vein 1-M 3.0 × as long as vein 1-SR and curved; vein r ends slightly before level of apex of pterostigma; first subdiscal cell robust, 2.9 × as long as its maximum width, vein cu-a entirely pigmented. Legs. Hind coxa robust, without tubercle dorsally and with strong and sparse rugae (Figs 7,8); hind femur widened, sparsely punctate and with whitish setae ventrally and dark brown setae dorsally, area in between punctures smooth and shiny, ventrally with 2 large acute teeth (the anterior one smaller than posterior one) and several denticles in between (Fig. 7); hind tibia 1.1 × as long as hind femur, basal narrow part of hind tibia about 1.2 × as long as widened part, widened part ventrally distinctly obliquely carinate (Fig. 7); hind basitarsus subparallel-sided, length of hind basitarsus 5.3 × as long as wide medially and 3.6 × as long as second tarsal segment (Fig. 7).
Metasoma. First tergite 6.0 × as long as its maximum width (Fig. 12), 1.4 × as long as second tergite, cylindrical, largely smooth except irregular rugae basally and some oblique aciculation after middle of tergite; remainder of tergites smooth and shiny; setose part of ovipositor sheath 1.1 × as long as body and 2.3 × as long as fore wing.
Colour. Black or blackish brown; tegula and palpi dark brown; scapus, pedicellus, malar space, mandible and patch near basal quarter of hind tibia partly brown; base of femora and of fore and middle tibiae and tarsi pale yellowish brown; remainder of fore and middle tibiae brown; veins and pterostigma largely dark brown, but base of pterostigma ivory; wing membrane slightly brownish but fore wing darkened near vein r and below parastigma; ovipositor sheath blackish apically (Fig. 1).
Male. Similar to female, but in most cases much smaller (Figs 2, 3).
Etymology. Named after the area of origin, "notios" being Greek for "southern".