A taxonomic study of Muscidifurax Girault & Sanders from China (Hymenoptera, Chalcidoidea, Pteromalidae)

Abstract Five species of Muscidifurax Girault & Sanders (Hymenoptera: Pteromalidae) are studied from mainland China, of which three new species, M.similadanacus Xiao & Zhou, sp. n., M.sinesensilla Xiao & Zhou, sp. n., M.neoraptorellus Xiao & Zhou, sp. n., and one newly recorded species, M.adanacus Doganlar, are reported. All species have been reared from pupae of Muscadomestica Linnaeus. A key to Chinese Muscidifurax and illustrations of external features of the species are provided.


Introduction
Muscidifurax was described by Girault and Sanders in 1910 to include M. raptor Girault and Sanders, parasitizing the common house fly (Musca domestica Linnaeus) from Illinois, USA. The genus can be recognized by the female antenna with one anellus and seven funicular segments (two anelli and six funicular segments in male), head protuberant at level of antennal toruli, marginal vein thickened in proximal half and progressively thinner in distal half. Since then, several researchers have studied the genus, including Graham (1969), Dzhanokmen (1978) and Bouček (1991). Kogan and Legner (1970) studied the genus and described four new species from Nearctic region. Doganlar (2007) described a new species of Muscidifurax which probably parasites Fannia sp. Thus, six valid species are described in the genus. All species are parasitoids of species of Calliphoridae and Muscidae (Diptera). Some species, such as M. raptor, were used in the biological control of the house fly (Legner 1971;Doganlar 2007). Until now, only one species, Muscidifurax raptor Girault and Sanders, has previously been recorded in China.

Materials and methods
All specimens were collected in the laboratory where they have been reared from pupae of house flies, and preserved in 75% ethanol. They were subsequently air-dried, point-mounted, and examined with a LEICA M10 stereomicroscope. Photographs were taken by using a Nikon Multizoom AZ100 system, and plates of illustrations were compiled using Adobe Photoshop® software. Five species have been identified, including three new species (M. similadanacus sp. n., M. sinesensilla sp. n., M. neoraptorellus sp. n.) and one newly recorded species (M. adanacus Doganlar). All type specimens are deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZCAS).
Morphological terminology follows that of Graham (1969), Bouček (1988), and Gibson et al. (1997). All specimens were examined and identified based on the studies of Kogan and Legner (1970), Doganlar (2007) and Girault and Sanders (1910). Body length (i.e. the length of body excluding the ovipositor sheaths) is measured in millimeters (mm), other measurements are given as ratios.
Abbreviations of morphological terms used are: Fu n funicular segment number; POL posterior ocellar distance; OOL ocellocular distance; Gt n gastral tergite number.
Description. Holotype. Female. 3.4 mm (Fig. 1). Head and mesosoma dark green, with metallic reflections and white hairs; gaster brown with yellow spot. Antennal scape brown, flagellum dark brown; legs yellow except coxae concolorous with body, femora and pretarsi brown; fore wings hyaline, venation brown except marginal vein dark brown.
Head in frontal view 1.25× as wide as high (Fig. 2); eyes with inner margins parallel, eye height 0.6× head height, eyes separated by 1.5× their height; antennal scrobes deep, reaching anterior ocellus. Antennal insertion on lower ocular line. Clypeal margin slightly protruded, straight; oral fossa 0.44× as wide as head; right mandible with four teeth, left mandible with three teeth. Head in lateral view with malar sulcus inconspicuous, eye height 1.74× malar space. Antennal scape length 1.44× eye height, exceeding vertex (Figs 2, 3); pedicel in lateral view 2.38× as long as broad; anellus transverse; Fu 1 1.8× as long as broad, slightly longer than Fu 2 ; each funicular segment with sensilla except Fu 1 ; clava not clavate, 2.25× as long as broad. Head in dorsal view (Fig. 4), 1.82× as wide as long; vertex convex; eye length 2.86× temple length; POL 1.33× OOL.
Remarks. This new species is similar to M. raptor and M. sinesensilla sp. n., but noticeably different by the absence of a marginal fringe on the fore wing. It is also very close with M. adanacus in having the fore wing without a fringe, but can be recognized with the characters listed in the key. Diagnosis. Fore wing with marginal fringe; inner margins of eyes angularly produced upwards (small angle shape) near the vertex; Fu 1 without sensilla; head 1.82× as broad as long dorsally; propodeum without coarse rugae; gaster 1.8× as long as broad. Description. Holotype. Female. 2.5 mm (Fig. 8). Head and mesosoma dark blue, with metallic reflections; gaster brown with yellow spot. Antennal scape yellowish brown, flagellum dark brown; legs yellow except coxae concolorous with body, and femora and pretarsi brown; fore wings hyaline, venation brown except marginal vein dark brown.
Head in frontal view 1.17× as wide as high; inner margins of eyes angularly produced upwards (small angle shape) near the vertex (Fig. 9); eye height 0.54× head height, eyes separated by 1.53× their height; antennal scrobes deep, not reaching anterior ocellus; reticulation in antennal scrobe smaller than that on parascrobe. Antennal insertion on lower ocular line, distance from upper margin of torulus to lower margin of anterior ocellus 1.78× distance from lower margin of torulus to lower margin of clypeus. Clypeus with longitudinal striation; clypeal margin slightly protruded, straight; oral fossa 0.5× as wide as head; right mandible with four teeth, left mandible with three teeth. Head in lateral view with malar sulcus conspicuous, eye height 1.25× malar space. Antennal scape length 1.34× eye height, reaching anterior ocellus, but not exceeding vertex; length of flagellum and pedicel combined longer than head width (1.2×); pedicel in lateral view 2× as long as broad; anellus transverse; Fu 1 1.67× as long as broad, slightly longer than Fu 2 ; each funicular segment with sensilla except Fu 1 (Fig.  10); clava not clavate, 2.35× as long as broad. Head in dorsal view, 1.82× as wide as long; vertex convex; eye length 2.55× temple length; POL 0.76× OOL.
Male. As female, with the following differences. Body length 2.0 mm (Fig. 13). Antennal insertion above the lower ocular line (Fig. 14), Fu 1 0.44× as long as scape, each funicular segment longer than broad, with 3-4 rows of setae.
Remarks. This new species is very similar to M. raptor having fore wing with marginal fringe and inner margins of eyes angularly produced upwards near the vertex. It differs from M. raptor in having the first funicular segment without sensilla, propodeum without coarse rugae. Etymology. The specific name is derived from the Latin sine-and sensilla, referencing the character of Fu 1 without sensilla. The name is to be treated as a noun in apposition.
Head in frontal view 1.13× as wide as high (Fig. 23); eye height 0.54× head height, eyes separated by 1.63× their height; antennal scrobes deep, not reaching anterior ocellus; reticulation in antennal scrobe smaller than that on parascrobe. Antennal insertion on lower ocular line, distance from upper margin of torulus to lower margin of anterior ocellus 1.56× distance from lower margin of torulus to lower margin of clypeus. Clypeus with longitudinal striation; clypeal margin straight, not protruded; oral fossa 0.46× as wide as head; right mandible with four teeth, left mandible with three teeth. Head in lateral view ( Fig. 24) with malar sulcus inconspicuous, eye height 1.24× malar space. Antennal scape length 1.33× as long as broad, reaching vertex; length of flagellum and pedicel combined longer than head width (1.28×); anellus transverse; each funicular segment longer than broad, Fu 1 1.38× as long as broad, as long as Fu 2 ; each funicular segment with sensilla except Fu 1 and Fu 2 (Fig. 24); clava not clavate, 2.67× as long as broad. Head in dorsal view, 1.75× as wide as long; vertex convex and with coarse reticulation; eye length 2.47× temple length; POL 0.75× OOL.
Male. As female, with the following differences. Body length 2.5 mm. Antennal insertion above the lower ocular line, each funicular segment longer than broad; Fu 1 0.5× as long as scape, longer than other funicular segments, 2.46× as long as wide. Lateral panel of metanotum golden (Fig 27). Gaster dorsum yellow in median area.
Remarks. This new species is very close to M. raptorellus, but noticeably different from M. raptorellus in having the first and second funicular segments without sensilla