The Lamelligomphus enigma

BREAKING NEWS: In a soon to be published article by Haruki Karube on Gomphidae in Vietnam this species is identified, as suggested in the entry below, as Lamelligomphus formosanus. It is much darker, but the structural characteristics match well. My specimen is identical to that by Karube, also in coloration (added May 21, 2014)

August 18 I walked along the stream leading up to the temple at Tay Thien, Tam Dao National Park. I noticed a gomphid sitting by the side of the stream on a branch and recognized it as Lamelligomphus camelus, a species that I had seen before at Ba Be National Park. Or rather, that I had not seen at Ba Be National Park, as has now become clear. I did not take any photos in the field, but decided to keep the specimen for comparison purposes. Recently, when looking into the Melligomphus of Ba Be, I took a more thorough peek at it. It was not L. camelus, as is obvious from various characteristics, most notably the lack of the two camel humps on S8. In fact the species keys out in the key provided by Wilson & Xu, 2009 as Lamelligomphus formosanus, but it also differs on various points, notably the pattern of the thorax, lacking antehumeral stripe and middle lateral stripe. It looks much more in many ways like L. hainanensis, but differs in the shape of the distal segment of the penis and in the fact that it has a thumb-like posterior branch of the anterior hamule (the reason why it keys out as L. formosanus).

For the moment we will keep this in the books as Lamelligomphus sp. nov? Here are a few impressions of the preserved specimen. Obviously, more work needs to be done.

Anterior hamule removed, showing strong bend tip to anterior branch and, obscured by the hairs, the thumb-like posterior branch

Note lack of dorsal tooth on superior appendage, but small teeth on the inner surface of the curved section

Clearly the humps of camelus are wanting

Facial pattern with small spots on labrum

Note strong shoulder on interior side of superior appendage and peculiar shape of lower appendage tip

Note relatively short flagellae

Lamelligomphus sp. nov?, male