Two new species of Aleocharinae ( Coleoptera , Staphylinidae ) found in fungus gardens of Odontotermes termites ( Isoptera , Termitidae , Macrotermitinae ) in Khao Yai National Park , Thailand

Discoxenus katayamai sp. n. and Odontoxenus thailandicus sp. n. are described from Khao Yai National Park, East Th ailand. Both species were collected from nests of termite of the genus Odontotermes Holmgren, 1912. Th ese are the fi rst records of both genera from Th ailand. Discoxenus katayamai is similar to D. indicus Wasmann, 1904, and O. thailandicus is similar to O. butteri (Wasmann, 1916). Each species is easily distinguished from their congeners by the body size, the number of the setae on the pronotum, elytra and abdomen and other characters discussed below.


Introduction
Many species of insects are known to be associated with termites, and especially with fungus-growing termites of the genus Odontotermes Holmgren, 1912, which is a host for various groups of termitophiles in their fungus gardens, e.g., beetles, fl ies and silverfi sh (Wasmann 1904(Wasmann , 1912(Wasmann , 1916;;Kistner 1969).David H. Kistner investigated the termitophile fauna in Khao Yai National Park, Th ailand, and reported some new species of staphylinid beetles (Kistner and Newton 1999;Jacobson and Kistner, 1999) and a few scuttle fl ies (Disney and Kistner 1997).However, no staphylinid beetles associated with Odontotermes termites have been reported from Th ailand.
In 2007, the junior author and his colleagues investigated termitophilous insects in Khao Yai National Park, and they found several new species of termitophiles.Two of them are described new species of staphylinid beetles, one in the genus Discoxenus (Wasmann, 1904) belonging to the tribe Aleocharini and one in Odontoxenus Kistner, 1958 belonging to the tribe Pygostenini.All the specimens were found in fungus gardens of Odontotermes termites; both genera have not been previously known from Th ailand.
Th e genus Discoxenus was described by Wasmann (1904) to accommodate two species from India.Later Wasmann (1916) described two species from Sri Lanka.Kistner (1975) revised the genus and added three species from India, Malaysia and Myanmar.Th us, seven Discoxenus species have been known in the Oriental Region.

Material and methods
Th e fi eld research was conducted in 2007, by M. Maruyama, Yûji Katayama and Takashi Komatsu in Khao Yai National Park, 30 km northeast of Bangkok.Th e fungus garden was carefully removed from the nest and crushed little by little on a white plastic tray to fi nd symbiotic insects.Th e insects were observed and photographed on fragments of the fungus garden.Th ey were fi nally put in 2 ml vials with 80% ethanol.
Th e technical procedures used here are generally as described in Maruyama (2006).Measurements are all in millimeters with averages and standard variations in parentheses.
Number of macrosetae is confi ned to both sides of the body, except for that of tergite IX on one side of the body.
Habitus photographs were taken with Microptics system and merged with the automontage software CombineZM.Th e symbiotic termite was identifi ed by Yoko Takematsu.However, the current taxonomic status of the genus Odontotermes is still not settled, and the identifi cation of the termite species in this paper is tentative (Takematsu, personal communication).
Holotypes and most of the paratypes of new species are deposited in the Kyushu University Museum (KUM), and some of paratypes are deposited in the National Park, Wildlife and Plant Conservation Department, Th ailand (DNP).

Biological notes
Th ese new species were found in the fungus gardens of Odontotermes proformosanus (Figs 5A-5B).Th e scuttle fl ies Clitelloxenus perdosetae Disney, 1997, C. thailandae Disney, 1997, Franssenia sp., Crasilla sp. andDicranopteron sp. were also caught at the same time.Th e individual number of each species was very low, compared to D. malaysianus collected in a high number from a few Odonototermes Holmgren, 1912 nests in Malaysia (Kistner 1982).Only a few specimens of D. katayamai (Fig. 5C) were found in one nest, which generally contained one to ten, fi st-sized fungus gardens, and none or one specimen of O. thailandicus was found in one nest, though density of the host termites was very high at Mo Sing To, the type locality of the present new species.Th e behavior of D. katayamai was almost the same as it was reported for D. malaysiensis by Kistner (1982).Th e behavior of O. thailandicus (Fig. 5D) was similar to that of D. katayamai, but it moved much slower than D. katayamai and it often stopped.

Figure 1 .
Figure 1.Habitus of Discoxenus katayamai.A dorsal view and B ventral view.

Figure 3 .
Figure 3. Habitus of Odontoxenus thailandicus.A dorsal view and B lateral view.

Figure 4 .
Figure 4. Odontoxenus thailandicus.A elytron B pronotum C male abdominal tergite VIII D male abdominal sternite VIII E male abdominal tergite IV & V F female abdominal tergite VIII G median lobe of aedeagus, and H spermatheca.