Whispy things

If you look closely in grassy wet places, you cannot miss them, but if you do not look closely, you may well overlook them, the Whisps. Two species are especially common in Northern Vietnam (and in many other places): Agriocnemis pygmaea and A. femina. They also look a lot alike. A. pygmaea prefers grassy verges of streaming water, whereas A. femina is more commonly represented in wet, inundated grassland. But they can often be seen side by side. The best distinguishing feature are the long lower appendages of A. femina, and that species becomes whiter with pruinosity than A. pygmaea.

Very white Agriocnemis femina, male, showing long appendages

About as white as they get, Agriocnemis pygmaea, male, showing absence of long lower appendages

Another pruinose male A. femina

Less pruinose, but clearly long appendages, A. femina, male

Non-pruinose A. pygmaea, male

Non-pruinose A. femina, male

Female Agriocnemis femina

Same female in close-up, showing dark markings on prothorax