When on June 24 I caught a female Asiagomphus along an otherwise also very productive stream in northern Bac Kan Province, it was immediately clear to me that this was one of the Chinese species and not any of the species I had seen in Vietnam so far, because of exactly these longitudinal markings on the abdomen. The shape of the occipital ridge and the lateral markings on S2-4 helped clinch the ID as Asiagomphus hainanensis, an addition to the Vietnamese list, but a species widespread in neighboring China.
To my shame and regret, I did not take proper photos of the dorsal view of the abdomen in the field, nor back at the room we stayed in at Ba Be National Park. Therefore the dorsal pattern is difficult to see in the accompanying photos taken of the preserved specimen.
|Asiagomphus hainanensis, female, Bac Kan Province, June 24. Note the lack of transverse bands on the abdomen (apart from S7, the pattern of lateral spots on S3 (two), the humeral spot and largely yellow metepisternum.|
|Detail of S2-3|
|Longitudinal markings on the dorsum of abdominal segments|
|Facial pattern and shape of occipital ridge|