Philosina buchi

On June 7 on the way to Mau Son I could not help to check some streams in the general area where one upon a time Echo maxima had been collected. The stream along QL 1A is pretty polluted, but just north of QL279 there is a feeder stream that runs into it that is really not bad at all, even if it runs from a village somewhat further upstream. Maybe there are even better stretches past that village. We checked the stream and apart from a nice Nihonogomphus thomassoni / lieftincki (I now lean towards thomassoni, but if it is one and the same species, who cares) saw at least 15 Philosina buchi, sometimes 3-4 together. I also noticed interesting interaction between males. One male flew towards another and perched close to it, after which both at regular intervals raised their wings somewhat up in one short jerky motion. This lasted for a few minutes, until the original intruder flew off again. The remaining male thereafter sat still.

Philosina buchi, nice male

Two males in close proximity, the lower one had flown in just before and both were at regular intervals raising their wings somewhat in an apparent intimidation display.