A few interesting Calopterygids from Bac Kan and Cao Bang Provinces

I know this stream along the TL257 in Bac Kan, at Km 58, that has some really interesting Gomphids in spring. So on August 30 I paid it a visit. And not in vain. The price of the day went to Matrona taoi, a rare endemic Matrona species, recently described from Xuan Son and apparently also known from Quang Binh Province in Central Vietnam. It may be more widespread. The stream I visited is not special, running along a clearing with cultivated fields and degraded forest on one side. It is not particularly wide either, 2 meters or less in most places. But along the stretch of about 400m I counted 4 males of this wonderful species. A few Matrona basilaris were also present, and many Vestalis gracilis.

The next day along the TL212 in Cao Bang I visited a small stream by the road side in a pocket of rice fields and houses. This stream also seems like nothing special, but it had 4-5 males of Atrocalopteryx coomani. This is a relatively widespread, but definitely scarce species. In Pia Oac I found another Matrona basilaris. Clearly the advent of autumn is bringing other species!

Male Matrona taoi, a beautiful and rare damsel

Showing the wing pattern, with lighter outer thirds

Scan of male Atrocalopteryx coomani, with also a very interesting wing pattern

Which is not visible in the perched insect, apart from the short moments it will flash its wings