Rhinocypha huai, or rather "Rhinocypha sp. from drusilla group"?

Rhinocypha huai has been described from Hainan by Zhou & Zhou in 2006. Later it was also recorded on the Chinese mainland. This species is very similar to Rhinocypha arguta, described from Thailand in 1997 by Hamalainen & Divasiri (and other species in the drusilla group). Typical R. arguta has all black S9 and S10, whereas huai has extensive orange-red on S9 and also red on S10. Since then R. arguta has also been reported from Vietnam, from Xuan Son National Park. However, the males I observed there had variable, although limited amounts of orange-red on S9 (two separate spots) and S10. Toan and Cuong recorded Rhinocypha huai in June 2010 from Huu Lien. I observed one male on November 16 and took a few record shots. Indeed it has extensive orange on S9 and S10, and restricted black on the other segments. I have not studied the specimen in hand, so cannot say anything on the structural characteristics, but otherwise it is very much like R. arguta. More study is clearly needed. Matti Hamalainen in private communication pointed out to me that both the Xuan Son and Huu Lien specimen have some differences from typical R. arguta and R. huai and are for the time being best treated as Rhinocypha sp. from drusilla group. They are also different from each other, notably in the pattern of S2, and the amount of black on the distal parts of the abdominal segments.

Rhinocypha sp. from drusilla group, male.