Hybrizon Fallén (Hymenoptera, Ichneumonidae, Hybrizoninae) found in Hunan (China)

The species of the genus Hybrizon Fallen (Hymenoptera: Ichneumonidae: Hybrizoninae) from China are reviewed, with special reference to Hunan (South China). The genus Hybrizon and two species (H. flavofacialis Tobias, 1988, and H. ghilarovi Tobias, 1988) are reported for the first time from the Oriental region. The species known from the Palaearctic and Oriental regions are keyed.


Introduction
The small subfamily Hybrizoninae Blanchard, 1845 (= Paxylommatinae Foerster, 1862, Hybrizontinae of authors, "Hybrizonites" of Blanchard, 1845;Wharton and van Achterberg 2000) is associated with ants and most likely belongs to the family Ichneumonidae, but was often associated with Braconidae ( van Achterberg 1976) or considered to be a separate family (He 1981, Tobias 1988).The group is treated as a subfamily of the family Ichneumonidae Latreille, 1802, by Rasnitsyn (1980) and Yu and Horstmann (1997) because of the structure of the connection of the second and third metasomal tergites and the venation of the hind wing, both indicate a closer relationship with the family Ichneumonidae (Sharkey and Wahl 1987;Wahl and Sharkey 1988) than with the Braconidae.From analysis of the 28S ribosomal RNA from the genus Hybrizon Fallén, 1813, it may be concluded that the Hybrizoninae are at a basal position of the Ichneumonidae-lineage (Belshaw et al. 1998;Quicke et al. 2000;Belshaw and Quicke 2002), but Gillespie et al. (2005) documented the unusual structure of 28S in Hybrizon, which makes alignment difficult.Quicke et al. (2009) found that Hybrizon likely is a derived subfamily within the ophioniformes-group of the Ichneumonidae, which agrees with the derived morphology of the Hybrizoninae.
The subfamily is known only from the Holarctic region and we report for the first time two species of the genus from the Oriental part of China.There are only two reports of the genus Hybrizon from China (He 1981, Konishi et al. 2012) but only from Palaearctic northern China (H.buccatus (de Brébisson, 1825) from Jilin and Heilongjiang and H. ghilarovi Tobias, 1988, from Jilin).The second author collected in Hunan province two species of the genus, resulting in an enormous extension of the known distribution by 2200+ km southwards.
The biology of the Hybrizoninae has been for long time uncertain, but recently oviposition has been documented by photographing and filming two different genera (Komatsu and Konishi 2010;Gómez Durán and van Achterberg 2011).It shows that the final instar ant larva is used for oviposition when the worker ants transport the larvae outside the nest.Of one species (H.buccatus) we have some host records indicating that predominantly ant larvae from the subfamily Formicinae (Formicidae) are selected, but also larvae from non-Formicinae may be used (Gómez Durán and van Achterberg 2011).It is too early to conclude a lack of specialisation, because in most cases the true nature of the associations has not really been established and the host associations are largely unknown for the other species.

Material and methods
The collecting site is at the border of the Southeast Lake near Yuanjiang (N.Hunan) in the common reed (Phragmites australis (Cav.))zone, with Oriental "Lasius fuliginosus" (= Lasius fuyi Radchenko, 2005; see Radchenko 2005) as possible host.The collecting in this wetland habitat along the lake was rather cumbersome and done by hand netting among the common reed.
For references to genera and species of Hybrizoninae, see Yu et al. (2009) and updates, for the East Palaearctic species, see Konishi et al. (2012) and for morphological terminology, see van Achterberg (1988).The specimens are deposited in the College of Bio-Safety Science and Technology, Hunan Agriculture University (HUNAU) at Changsha and in the NCB Naturalis collection (RMNH) at Leiden.
Notes.A female paratype is illustrated by Konishi et al. (2012).Up to recently only known from Far East Russia and Bulgaria, but Konishi et al. (2012) report this species from NE China (Jilin), Korea and Japan.New for the Oriental region.
The Old World species can be separated as follows: Key to Old World species of the genus Hybrizon Fallén Vein r of fore wing issued comparatively far removed from base of pterostigma; mesoscutum without bands of punctures, at most with some punctures; vein 1-M of fore wing as dark as vein 2-CU1 of fore wing; scapus about as large as pedicellus; scutellum (except medio-anteriorly) and more or less notaulic area of mesoscutum ivory; length of fore wing 3.0-3.6mm; propodeum distinctly rugose-granulate; Spain, South Korea ...................H. juncoi (Ceballos, 1957)