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

Abstract A new species of Anteon Jurine, 1807 is described from Laos, Houaphanh Province: Anteon holzschuhi sp. n. Morphologically the new species is similar to Anteon semipolitum Olmi, 2008, but it is distinguished by the sculpture of the face partly reticulate rugose and partly with deep punctures similar to areolae; in Anteon semipolitum the face is completely punctate and unsculptured among punctures. In addition, in the new species the distance from the outer edge of a lateral ocellus to the compound eye (OOL) is about 3.3 times as long as the distance between the inner edges of a lateral ocellus and the median ocellus (OL); in Anteon semipolitum OOL is less than twice as long as OL. Published identification keys to the Oriental species of Anteon are modified to include the new species.

The species of Anteon inhabiting the Oriental region were studied by Xu et al. (2013). More recently,  and  described further new species respectively from Indonesia (Anteon seramense Guglielmino & Olmi) and Thailand (Anteon huettingeri Olmi, Xu & Guglielmino). In total, 150 Anteon species have been described from the Oriental region (Xu et al. 2013;.
Anteon species are parasitoids of leafhoppers belonging to the 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 hostfeeding (Olmi 1984(Olmi , 1994.
In 2015 we examined additional specimens of Anteon from Laos 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 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.
Remarks. The new species is similar to A. semipolitum Olmi, 2008, by having the antenna filiform, notauli reaching about 0.8 × length of scutum (Fig. 1A), posterior surface of the propodeum with two complete longitudinal keels and unsculptured median area, distal part of stigmal vein much shorter than proximal part, paramere about as long as penis, without papillae on inner side, without distal inner process (Fig. 2) and distivolsella not provided with two lateral processes (Fig. 2). The main difference between the two species is in the facial sculpture (face partly reticulate rugose and partly sculptured by deep punctures similar to areolae in A. holzschuhi (Fig. 1B); face punctate and unsculptured among punctures in A. semipolitum). In addition, OOL is about three times as long as OL in A. holzschuhi, less than twice in A. semipolitum. In the key to the males of Oriental Anteon published by Xu et al. (2013), the new species can be included by replacing couplet 43 as follows:

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Head partly or totally reticulate rugose (Fig. 1A, B) (Fig. 1B); OOL about 3.3 times as long as OL (Fig. 1A)  In comparison with the 77 species listed in the Chinese province of Guangdong (total area: 177900 km 2 ) (Xu et al. 2012c), the dryinid fauna of Laos (total area: 237800 km 2 ) is poorly known. Some common genera such as Gonatopus Ljungh, 1810 (no species listed in Laos) are clearly understudied. Further evidence of this is the fact that on the small island of Hainan (total area: 33210 km 2 ; 1/7 that of Laos) 56 species of Dryinidae are recorded (Xu et al. 2011a(Xu et al. , 2011c. In contrast, in the more northern Chinese provinces of Shaanxi (total area: 205800 km 2 ) and Hunan (total area: 210000 km 2 ) only 36 (Xu et al. 2012a) and 17 (Xu et al. 2011b(Xu et al. , 2012b(Xu et al. , 2013 dryinid species have been recorded, respectively.