A new species of the genus Anteon Jurine (Hymenoptera, Dryinidae) from Thailand

Abstract A new species of Anteon Jurine, 1807 is described from Thailand, Nan Province: Anteon huettingeri sp. n. Morphologically the new species is similar to Anteon borneanum Olmi, 1984, Anteon jurineanum Latreille, 1809, Anteon insertum Olmi, 1991, Anteon yasumatsui Olmi, 1984, Anteon sarawaki Olmi, 1984, Anteon thai Olmi, 1984 and Anteon krombeini Olmi, 1984, but it is clearly different for the numerous sensorial processes present on the inner side of the paramere; these processes are absent in the other above species. Published identification keys to the Oriental species of Anteon are modified to include the new species.

The species of Anteon inhabiting the Oriental region have been recently studied by Xu et al. (2013). In total 149 species have been described from the Oriental region Xu et al. 2013).
Anteon species are parasitoids of leafhoppers belonging to Cicadellidae . As in almost all dryinids, females of Anteon have a chelate protarsus. Chelae are used to capture and restrain the host during oviposition and host-feeding (Olmi 1984(Olmi , 1994.
In 2014 we examined additional specimens of Anteon from Thailand and discovered a new species described in this paper.

Material and methods
The descriptions follow the terminology used by Olmi (1984) and Xu et al. (2013). The measurements reported are relative, except for the total length (head to abdominal tip, without antennae), which is expressed in millimetres. The following abbreviations are used in the descriptions: POL is the distance between the inner edges of the two lateral ocelli; OL is the distance between the inner edges of a lateral ocellus and the median ocellus; OOL is the distance from the outer edge of a lateral ocellus to the compound eye; OPL is the distance from the posterior edge of a lateral ocellus to the occipital carina; TL is the distance from the posterior edge of an eye to the occipital carina.
The types of all Oriental species of Anteon have been previously examined by the authors.
The type specimen described in this paper is deposited in the collection of the Oberösterreichisches Landesmuseum, Linz, Austria (OLL).
The description of the new species is based on the study of only a single specimen. The authors are aware that descriptions of new taxa should normally be based on more individuals. However, Dryinidae are so rare that it is uncommon to collect more than one specimen of each species. In addition, on the basis of the experience and knowledge of the authors, the new species is sufficiently delimited by unique characters to justify its description.
Diagnosis. Female: Fully winged; rarely brachypterous; occipital carina complete; palpal formula 6/3; antenna without rhinaria; forewing with three cells enclosed by pigmented veins (costal, median and submedian); forewing with stigmal vein and pterostigma; distal part of stigmal vein much shorter than proximal part, occasionally slightly shorter, as long as, or longer than proximal part; propodeum usually with transverse keel between dorsal and posterior surface; protarsus chelate; inner side of enlarged claw with proximal prominence bearing one long bristle; tibial spurs 1/1/2. Male: Fully winged; rarely brachypterous; occipital carina complete; vertex of head usually without two oblique keels connecting posterior ocelli to occipital carina; palpal formula 6/3; forewing with three cells enclosed by pigmented veins (costal, median and submedian); forewing with stigmal vein and pterostigma; distal part of stigmal vein much shorter than proximal part, occasionally slightly shorter, as long as, or longer than proximal part; pterostigma less than four times as long as broad; propodeum usually with transverse keel between dorsal and posterior surface; paramere without inner branch wrapping penis; tibial spurs 1/1/2. Diagnosis. Male with antenna filiform; scutum very slightly granulated and finely punctate; posterior surface of propodeum without longitudinal keels; paramere without distal inner process, with inner side provided with many sensorial processes (Fig. 1). Description. Male. Fully winged ( Fig. 2A). Length 2.2 mm. Head black, except mandible testaceous. Antenna testaceous. Mesosoma black. Metasoma brown. Legs testaceous, except metacoxa partly black. Antenna filiform. Antennal segments in following proportions: 11:6:6:5:5:6:5:5:5:7. Head dull, granulated and reticulate rugose. Face with two lateral keels around orbits directed towards antennal toruli. Vertex with two short oblique keels from posterior ocelli to occipital carina. Occipital carina complete. Frontal line complete. Vertex with POL = 6; OL = 3; OOL = 4; OPL = 3; TL = 4; greatest breadth of posterior ocelli as long as OPL. Scutum shiny, very slightly granulated, finely punctate, unsculptured among punctures. Notauli incomplete, reaching approximately 0.4 × length of scutum. Scutellum and metanotum unsculptured, shiny. Propodeum with strong transverse keel between dorsal and posterior surface. Dorsal surface of propodeum reticulate rugose. Posterior surface of propodeum without longitudinal keels, with median area granulated and lateral areas reticulate rugose. Forewing (Fig. 2B) hyaline, without dark transverse bands. Distal part of stigmal vein much shorter than proximal part (2:5). Paramere (Fig. 1) without distal inner process, with inner side provided with many small sensorial processes. Tibial spurs 1/1/2.   Etymology. The species is named after the collector, Dr Ernst Hüttinger. Remarks. Because of the antenna filiform, the scutum neither rugose nor sculptured by irregular keels, the posterior surface of the propodeum without longitudinal keels, the paramere without distal inner process, the new species is similar to A. borneanum Olmi, 1984, A. insertum Olmi, 1991, A. jurineanum Latreille, 1809, A. krombeini Olmi, 1984, A. sarawaki Olmi, 1984, A. thai Olmi, 1984and A. yasumatsui Olmi, 1984. The main difference between A. huettingeri and all other species is centered on the structure of the inner side of the paramere (with many sensorial processes in A. huettingeri (Fig. 1); without sensorial processes in the other species (Plates 20 C, 30 D, 31 C, 31 D, 32 C, 43 B, 48 A, 50 E in Xu et al. 2013)). In the key to the males of Oriental Anteon published by Xu et al. (2013), the new species can be included by replacing couplet 9 as follows: 9

Anteon huettingeri
Inner side of paramere with many small sensorial processes (Fig. 1)  In comparison with the 193 species recorded in China by He and Xu (2002) and the 62 and 40 listed respectively in India and Laos (Xu et al. 2013), the dryinid fauna of Thailand is poorly known. Some genera such as Gonatopus (with only seven species listed) are clearly under studied.