A new species, first report of a male and new distributional records for three species of Pteroptrix (Hymenoptera: Aphelinidae) from China

Abstract Background The Chinese fauna of Pteroptrix currently includes 26 species, of wihich 19 species were described originally as new from China: 2 by Howard (1907), 2 by Compere (1953), 1 by Flanders (1966), 1 by Viggiani and Ren (1986), 4 by Huang (1991), 4 by Huang et al. (1992), 1 by Viggiani and Ren (1993), 4 by Huang (1994). New information Pteroptrix pedicellata sp. n. is described in detail and illustrated; the male of P. processa (Huang) is reported for the first time. New distributional data for three species, P. leptocera (Huang), P. orientalis (Silvestri) and P. processa (Huang), are also provided from China.


Introduction
The genus Pteroptrix was established by Westwood (1833) with Pteroptrix dimidiatus Westwood as the type species and currently comprises 71 valid species (Noyes 2016). All the species of the genus are parasitoids of armoured scale insects (Hemiptera: Diaspididae) which are economically important pests. The taxonomy of the genus had been highly controversial for a long time until Viggiani and Garonna (1993) proposed Archenomus Howard and Aphelosoma Nikol'skaya as synonyms of Pteroptrix. Faunal contributions to the systematic study of the genus had been made by several authors, such as Hayat (1979) on the Australian fauna; Prinsloo and Neser (1990) on the southern Afrotropical fauna; Nikol'skaya and Yasnosh (1966), Viggiani and Garonna (1993) Hayat (1998), Hayat and Khan (2010) on the Indian fauna; Huang (1994) on the Chinese fauna.

Materials and methods
All specimens in the present study were collected by sweeping, or yellowpan trapping, then dissected and mounted in Canada balsam on slides following the method described by Noyes (1982). Photographs were taken with a digital CCD camera attached to an Olympus BX51 compound microscope and final modifications to the images were made using Adobe Photoshop. Most measurements were made from slide-mounted specimens using a reticle eyepiece in a microscope, except the total body length (excluding the ovipositor) which was measured from alcohol-preserved specimens before being dissected. All measurements are given in micrometres (μm) except body length which is measured in millimetres (mm). Scale bars are 100μm except those which are specifically indicated. All the specimens listed below are deposited in Northeast Forestry University, Harbin, China.
Terminology follows Hayat (1998) except mesosoma is used for the thorax plus propodeum and metasoma for the petiole plus gaster. The following abbreviations are used in the text:  scutellum 0.40× as long as wide and 0.63× as long as mid-lobe of mesoscutum. Placoid sensilla very close to the anterior scutellar setae; distance between anterior pair of scutellar setae 1.50× as long as the distance between posterior pair. Propodeum 2.60× the median length of metanotum and slightly salient posterior-medially. Mesopostphragma extending to posterior margin of TII. Fore wing (Fig. 1d) 3.55× as long as wide, densely and evenly setose; costal cell 1.58× as long as marginal vein, with 4 setae distally on dorsal surface and 4 relatively shorter setae medially on ventral surface; submarginal vein with 1 seta, marginal vein with 4 long setae along anterior margin; basal cell with 2 setae below apex of submarginal vein; marginal fringe 0.71× as long as the greatest width of disc. Hind wing 8.8× as long as wide, with 3 rows of setae on disc; marginal fringe 2.5× the greatest width of disc. Legs (Fig. 1e) . 1c) with 11−13 setae, each side lobe with 1 seta. Fore wing (Fig. 1d) 3.54−3.58× as long as wide and with its marginal fringe 0.71−0.77× wing width. Ovipositor 1.16−1.23× as long as mid-tibia and with its second valvifer 2.70−3.11× as long as third valvula. The third valvula 1.38 −1.54× as long as mid basitarsus.

Etymology
The specific name refers to the fact that this species is with normal sized pedicel in comparison with Pteroptrix macropedicellata (Malac).

Tibet, Chayu County, Xiachayu Town
Comments: The new species belongs to the dimidiata-group (Viggiani and Garonna 1993) and superficially resembles P. macropedicellata (Malac) in having a similar body colour and setation on the mid-lobe of the mesoscutum. However, the new species can be separated from the latter (according to the description and figures of Nikol'skaya and Yasnosh (1966)) by the following combination of characters. Pteroptrix pedicellata sp. n. with relatively longer antennal scape, about as long as the combined length of pedicel, F1 and F2 (vs about as long as pedicel and F1 combined); normal sized pedicel, 1.58−1.76× as long as wide (vs 2×) and distinctly shorter than F1 + F2 (vs about as long as F1 + F2); shorter F1, 1.22−1.86× as long as wide (vs more than 2×); side lobe of mesoscutum with only 1 seta (vs 2 setae); relatively narrower fore wing, 3.54−3.58× as long as wide (vs about 3.11×).
Pteroptrix leptocera: Viggiani and Ren (1993) Comments: Although this species was adequately described and illustrated by Huang et al. (1992), this is the first record from Yunnan Province, China.

Distribution
China ( Comments: Our specimens agree well with the description of Huang (1994), but the following difference should be noted: in the material from Qingdao City, F3 as in Fig. 2 with one sensillum (sensilla present only on clava segments in Huang s description).

Description
Male. Body length 0.5 mm. Colouration similar to that of female, largely brown to dark brown. Antenna (Fig. 3a) with radicle 2.73× as long as wide; scape 4.33× as long as wide; pedicle slightly longer than wide and 0.63× as long as F1; funicle segments with F2 shortest, F3 a little longer than F1. Mid-lobe of mesoscutum with 2 setae, propodeum distinctly salient posterior-medially and 3.6 × as long as metanotum. Fore wing (Fig. 3b) 2.8 × as long as wide, marginal fringe 0.48 × as long as the greatest width of wing. Genitalia as in Fig. 3c and 0.55 × as long as midtibia.

China (Fujian, Jiangsu, Beijing [new record], Shaanxi [new record]).
Comments: This species is unique for the genus in having the mid-lobe of mesoscutum with only 2 setae and propodeum distinctly salient posterior-medially. This is the first report for its male.