Devadatta cyanocephala is known from Lao and several provinces in Vietnam, including Ha Tinh. As far as I know this is the furthest north is has been recorded until now. When I revisited the place in June I could not find any, so possibly it is a spring species.
|Male Devadatta cyanocephala. Like congeners darkened wingtips. But it has pale lines on the thorax over the sutures.|
|Under this angle the distinctive blue face becomes apparent|
|And right from the front it can no longer be ignored: this is a blue face. It makes it easy to separate this species from its cousins. Imaging being a small bug and being devoured by something so blue! What a way to go.|
|Here is a not so good shot in hand of the female. Note the broad stripe over the flank.|
|Her face is still blue, but not as blue blue as that of the male|