Thursday 2 January 2020

Asiagomphus mayhem - Vietnam is the place to be


August 2018 I finally was able to publish the results of 4 years of chasing Asiagomphus species in Vietnam. The paper that appeared in Zootaxa that year provided information on 8 species from this diverse genus. Asiagomphus acco is one of the easy species to recognize and had been recorded from Vietnam before. It is widespread and I published it on the blog long ago. Another species that is, at least in hand, easy to recognize is Asiagomphus reinhardti, which had only recently been described from neighboring Cambodia. The male has highly distinctive appendages, quite different from all other species in SE Asia. I found it both in Lam Dong Province and in Gia Lai Province. Here is an example in hand.

Male Asiagomphus reinhardti, caught May 17, 2016, near Bao Loc
As pointed out elsewhere in the blog, the most widespread species of Asiagomphus in northern Vietnam is probably A. auricolor. The original description by Fraser was based on a female and it had been hard to match it with its female. In my paper I give a first description of the male and provide further information on the female. Photos of this species are included already on this blog in past entries.

In neighboring Thailand Asiagomphus xanthenatus occurs and I was able to verify the occurrence of this species in central Vietnam, where I one lucky day ran into three males. Here is a photo of one of these.

Asiagomphus xanthenatus male, May 15, 2016 from Quang Nam Province.
Near Da Lat in Lam Dong Province, not that far actually from where I collected A. reinhardti (Bao Loc), I found a new species to science, Asiagomphus kosterini, which I reported already in this blog. 

That leaves us with 3 more species. One of these is a species with longitudinal stripes on the abdomen, different from all other species in Vietnam, although this pattern occurs on many of the northern species. This is Asiagomphus pacificus, which I found in Cao Bang Province and Bac Kan Province in the north. I reported this species already previously within this blog.

Which leaves us with two tricky species that I also already showed on the blog. Both turned out to be new to science and both are rather similar to some of the other species shown in this entry. These are Asiagomphus superciliaris and Asiagomphus monticola. Here are examples of both.

Male Asiagomphus monticola, Yen Bai Province, June 1, 2014

Asiagomphus monticola male, Xuan Son NP, May 31, 2014

And finally Asiagomphus superciliaris, Huu Lien Nature Reserve, May 24, 2014
Comparing the photos of these last three species, all similar to A. auricolor too, may leave the casual observer somewhat bewildered. Indeed, these species are rather difficult, if not impossible, to identify in the field without in-hand inspection. The details of the caudal appendages and secondary genitalia provide good clues. If you carry a copy of my Zootaxa paper, which provides these clues, you should be able to identify them and release them again.

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