2 males Heliogomphus scorpio on May 15, 2014, at Xuân Son
I spotted this elegant Gomphid for the first time in May 2014, resting on leaves or rocks along forested streams.
During 2 years, I misidentified it with another Heliogomphus, apparently undescribed, found at Tam Dao, until I bumped into the true scorpio (at Xuân Son).
Some characteristics : almost entirely dark abdomen with a pale ring at the base of the 7th segment, S7-10 broadened, face largely black with a whitish stripe on frons, synthorax with a dorsal stripe connected to the collar stripe to form a 7-shaped mark, superior antehumeral spot and.... terrifically gruesome appendages!
Heliogomphus scorpio male on May 23, 2014 at Tam Dao (alt. ca 300m)
Male in hand, from Tam Dao
Abdomen tip, dorsal view : superiors lyrate in shape, convergent, curled strongly,
with a long, strong basolateral spine
Other Heliogomphus species known in Vietnam (that I am aware of): H. retroflexus (in the North), H. chaoi (South, type locality is Lam Dong Province) and H. selysi.