A new species of Hyperimerus Girault from China, with a key to species of the genus (Hymenoptera, Chalcidoidea, Pteromalidae)

Abstract A new species of Hyperimerus Girault (Hymenoptera: Pteromalidae), H.sichuanicus Yang & Xiao, sp. n., is reported and described for the first time from mainland China. A key to the worldwide species of Hyperimerus and illustrations of external features of the species are also provided.


Introduction
The genus Hyperimerus was erected by Girault (1917) to include Hyperimerus corvus Girault from California, USA, and the genus was placed in the subfamily Erimerinae of Callimomidae. Subsequently, Hyperimerus was put in the tribe Asaphini under Pteromalidae by Peck (1951). Graham (1969) upgraded the tribe Asaphini to subfamily Asaphinae. Since then, several researchers reported Hyperimerus from Europe (Graham 1969;Bouček 1977;Dzhanokmen 1978;Kalina 1989;Ulrich 1999). Schender et al. (2014) reviewed the genus and redescribed the two species, H. corvus Girault and H. pusillus (Walker). Until now, two valid species of Hyperimerus are known in the world.
Only one species, H. pusillus (Walker), has previously been reported in China (Huang and Xiao 2005). In this study, one new species, H. sichuanicus Yang & Xiao, sp. n., is described.

Materials and methods
All specimens for the present study were swept using an insect net and preserved in 95% ethanol. They were subsequently air dried, point-mounted and examined with a LEICA MZ APO stereomicroscope. Photographs were taken under the Nikon Multizoom AZ100 system, and the plates were compiled using Adobe Photoshop software. In addition, the author also examined the specimens of Hyperimerus deposited in the National History Museum, London in 2002. All type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences, China (IZCAS).
Morphological terminology mostly follows that of Bouček (1988) and Gibson et al. (1997). All specimens were examined and identified based on the studies of Graham (1969), Gibson and Vikberg (1998), Bouček and Rasplus (1991) and Schender et al. (2014). The new species is described based on the holotype specimen. Body length excluding the ovipositor sheaths is measured in millimetres (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 tergum number.

Taxonomy
Key to species Hyperimerus is similar to Asaphes in the subfamily Asaphinae, but it can be recognized by the antenna with one anellus and seven funicular segments (two anelli and six funicular segments in Asaphes), frenal line on scutellum indistinct (distinct in Asaphes), petiole transverse (petiole longer than broad and with longitudinal ridges in Asaphes).
Gaster ovate, 1.88× as long as broad, shorter than head and mesosoma combined. Petiole short, 0.5× as long as broad, dorsum with longitudinal ridges. Each gastral tergite smooth; Gt 1 with long hairy around petiole; Gt 1 and Gt 2 large and smooth, 0.47× length of gaster. Ovipositor sheaths distinctly produced in dorsal view; gaster in lateral view, ovipositor sheaths 0.47× length of gaster, 0.76× length of hind tibia.
Male. Body slender, scape yellowish-brown, antenna segmented clearly, others similar to the female.
Remarks. The new species is similar to H. corvus, but different by the antenna with Fu 1 shorter than pedicel, ovipositor sheaths shortly protruded. It is also very close to H. pusillus in having the Fu 1 shorter than pedicel, ovipositor sheaths shorter than 1/2 length of gaster, but can be recognized by the characters listed in the key.