Two red dragonflies

There is a very common red dragonfly in Vietnam (and many other parts of Asia), closely allied to Crocothemis erythraea, a well known species from Europe. It differs in some structural aspects and the clarity of the blackish line along the dorsum of the abdomen. This is  Crocothemis servilia. This common dragonfly is a possible reason why the apparently also quite common other very red dragonfly, Rhodothemis rufa, may be overlooked, at least by me. I have seen it only a few times, in Van Long Nature Reserve and in the suburbs of Ha Noi. This last fact is an indication it cannot be all that rare. Both species are roughly the same size. Rhodothemis rufa misses the black line along the dorsum and the blueish edge to the eyes. Its abdomen is also more rounded and the pterostigmata are blackish, not light. The female reminds me very much of female Erythemis peruviana of the New World.

Crocothemis servilia, male

Crocothemis servilia, female

Rhodothemis rufa, male

Rhodothemis rufa, female