Boyeria karubei, new to Vietnam

In the previous posting I introduced the first record for Vietnam of Boyeria karubei. When studying the specimen, the venation, with crossveins in the median space, RI3 unforked and with a single row of cells between IR3 and Rspl soon made clear it could not be Planaeschna. These characteristics pointed to the subfamily Gomphaeschnini of the Aeshnidae. From there it was a small step to Boyeria. There are 7 or 8 species in this genus, besides B. karubei, described from Laos, B. maclachlani and B. sinensis occur in East Asia. Two species are confined to North America and two to Europe. Boyeria jamjari, described by Jung in 2011 is very similar to B. karubei, maybe with more contrast, as it seems to have reddish bands on the abdominal segments, more contrast in the face and possibly the appendages are more rounded and the epiproct less concave, but this I judged from photos and is highly inconclusive as evidence. If this is the same species as B. karubei, that is the senior synonym. All aspects of the Xuan Son specimens sit very well with the description by Yokoi, measurements, penile organ, appendages and all. Only the antealar carina is not yellow, but yellowish brown and the number of antenodal and postnodal crossveins is less. See below the details and some close-ups of the penile organ.

Specimen 1 nodal index 22-25:23-21/22-19:18-22 TL 84 mm, ABD (incl app) 64 mm, HW 53 mm.
Specimen 2 nodal index 20-29:28-20/22-18:19-21 TL 82 mm, ABD (incl app) 62 mm, HW 52 mm.

Penile organ last segments, ventro-lateral

And lateral view