First record of the genus Lethades Davis, 1897 from the Oriental region, with description of a new species (Hymenoptera, Ichneumonidae, Ctenopelmatinae)

Abstract A new species of the genus Lethades Davis, 1897 (Ctenopelmatinae: Pionini), Lethades orientalis Reshchikov & Xu, sp. n., collected in Heishiding Nature Reserve in Guangdong Province, China, is described. This is new record of the genus from China and for the Oriental region also. The species can be distinguished from all other species of the genus by its black metasoma, the presence of an areolet on the fore wing, distinctly pectinate claws with teeth of the hind claw as high as the claw itself, and a complete longitudinal propodeal carina. A key to the world species of the genus is provided.


Introduction
The genus Lethades Davis, 1897, is in the tribe Pionini and the subfamily Ctenopelmatinae (Hymenoptera, Ichneumonidae). It formerly comprised 16 described species, two of them reported from the Nearctic Region and the rest from the Palaearctic Region (Yu et al. 2012).
The European species of Lethades Davis were reviewed by Hinz (1996a), who provided a key to the Palaearctic fauna. Afterwards, Kasparyan and Khalaim (2007) developed a key to the species of the Russian Far East based on Hinz's key. Two species, L. alpinus (Zetterstedt) and L. flavifrons (Zetterstedt) were synonymized with L. curvispina (Thomson) by Hinz (1996b) and L. poloniae Hinz, 1996 was synonymized with L. punctatissimus (Strobl) by Horstmann (2001). Cameron and Wharton (2011) transferred Hodostates schaffneri (Hinz) to Lethades based on ovipositor characters. In the Nearctic Region one species, L. kukakensis (Ashmead), is known from Alaska, and the other species, L. texanus (Ashmead) from Texas (Yu et al. 2012). One species, L. buriator Aubert, 1987 was described from The Republic of Buryatia (Eastern Russia) and five European species were recorded from the Eastern Palaearctic (Yu et al. 2012). Prior to this paper no species of either genus had been recorded from China or the Oriental Region. Here a new species is described from China, representing the first record of the genus from the Oriental region.

Materials and methods
Specimens were collected using sweep nets in the forests of Heishiding Provincial Nature Reserve, located in Fengkai County, Zhaoqing City, West Guangdong Province, bordering Guangxi, China (23°27'N, 111°53'E, 150-927 m) (Zhang 1997). The reserve consists of subtropical evergreen and broad-leaved forests. The region has a subtropical moist monsoon climate with mean annual temperature 19.6°C and mean monthly temperatures range from 10.6°C in January to 28.4°C in July (Wang and Liu 1987). Annual precipitation is approximately 1743.8 mm, with rainfall occurring mainly between April and September (79% of annual total), there is a pronounced dry season lasting from October to March (Wang and Liu 1987). Species belonging to the Fagaceae and Lauraceae families, which are broadly distributed in subtropical evergreen broadleaved forests, are the dominant tree species (Chan et al. 2004).
The holotype is deposited in the Hymenopteran Collection of South China Agricultural University, Guangzhou (SCAU). Images were taken using AxioCamHRc digital camera attached to Zeiss Discovery V20 microscope and stacked using Helicon Focus®. All images were further processed using various minor adjustment levels in Adobe Photoshop®. Stacked images are available in colour and high resolution at http:// www.morphbank.net. Morphological terminology mostly follows Gauld (1991). Wing vein nomenclature follows Ross (1936) and wing vein terminology follows Mason (1986Mason ( , 1990.

Diagnosis.
Lethades can be distinguished from all other genera in the Pionini by the combination of the following characters: first flagellomere longer than second; second trochanter of hind leg rounded without a transverse ridge; glymma present; profile of the propodeum nearly rounded with short posterior field; dorsomedian and dorsolateral carinae of the T1 converging at base; ovipositor without subapical notch; cerci parallel-sided and protruding (Townes 1970, Cameron andWharton 2011). The notaulus varies from absent to deep, but very short, in nearly all described species of Lethades. Only L. schaffneri Hinz has an elongate notaulus. The latter species was transferred to Lethades based on other characters, especially ovipositor morphology (Cameron and Wharton 2011). Claw distinctly pectinate, teeth of hind claw more than 0.5 times as high as claw (Fig. 7) (Fig. 4)  Diagnosis. This species can be distinguished from all other species of Lethades by a combination of the following characters: metasoma black (Fig. 1); fore wing with areolet; claw distinctly pectinate, teeth of hind claw as high as claw (Fig. 7); longitudinal propodeal carina complete (Fig. 4).

Key to world species of the genus Lethades
Description. Female. Body length 10.5 mm.
Head. Face and clypeus shagreened and covered with long reddish setae (Fig. 2). Face approximately 1.4 times as wide as high, with distinct, sparse and shallow punctures; median portion weakly and longitudinally convex (Fig. 2). Clypeus convex, gradually raised towards apical margin, with very sparse, fine and distinct punctures. Upper tooth of mandible obviously shorter than lower tooth. Malar space approximately 0.6 times as long as basal width of mandible. Gena, vertex and frons shagreened. Head with parallel sides behind eyes (Fig. 3). Gena in lateral view approximately as long as the width of eye. Postocellar line nearly 0.5 times as long as ocular-ocellar line. Antenna with 40 flagellomeres. Occipital carina complete.

Male. Unknown.
Etymology. The name of the new species refers to the Oriental Region.