The species is described this year (2014) by Matti Hamalainen despite of the fact that we have seen it flying in nature since 2008.
In the field trip to Huu Lien, Lang Son Province, North Vietnam with the species author for finding Echo maxina, I saw that species in a source of the stream that I collected the species Nihonogomphus schorri. This is the third undescribed species be known to science in trips of Echo maxima, in Huu Lien, Lang Son (see the topic Trips of finding Echo maxima Martin, 1904, mystery of mysteries).
It is interesting that this unknown species be in Matti's collection quite long time but it only be focused since a fellow (Sebastien Delonglee) sent the author its photos from Huu Lien in 2013. In my photo gallery, I keep the photos in two separated folders: males in A. atrocyana and the female in A. coomani folders. I remember that I did take photos of the species among bamboos near the deep and clear stream that runs directly from limestone mountain.
Matti Hamalainen as being informing the photos from Sebastien then found that it belong a distinguish species that difference from all known species then he described the species under the name: A. auco. He wrote in the etymological part of the description: "The species epithet auco is named after Âu Cơ, a character in the Vietnamese mythology. Âu Cơ was a young, beautiful mountain fairy who fell in love with Lạc Long Quân (the Dragon Lord of Lac). They married and she gave birth to an egg sac from which hatched a hundred children known collectively as the Bach Viet, the ancestors of the Vietnamese people. Âu Cơ is widely honoured as the mother of Vietnamese civilization."
Before deciding the name of the species, Matti emailed to me about his idea of the name of the species and I did full agree with his very interesting idea, the colorful wings of this group matches very well to Âu Cơ, who is a pretty girl and she is well known to any Vietnamese people and this will make the species to be more familial to Vietnamese.
Male of A. auco (on a bamboo leaf above) photographed by Cuong Do, same date to the holotype in Huu Lien, Lang Son Province
Female of A. auco (among bamboos) with white pseudo-pterostigma that make I misidentified it to be A. coomani, photographed by Cuong Do, same date to the holotype in Huu Lien, Lang Son Province