Lyriothemis pallidistigma - a beautiful dragonfly new for Vietnam*

*Adjusted after publication in Zootaxa of Lyriothemis pallidistigma Kompier, Holden & Makbun, 2021

Lyriothemis is a genus of beautiful flat-bellied dragonflies with 17 species, represented in Vietnam by several species, the distinctive L. bivittata and L. kameliyae, two forest species that breed in tree holes and the like, and the rare L. mortoni, known from Phu Quoc. Many species inhabit marshland. And fourth species had been found at Cat Tien National Park and identified as L. elegantissima. Subsequently, it became clear it in fact differs in structure and also a little in pattern. It has now been published as L. pallidistigma. 

In Cat Tien National Park it inhabits grassy inundated clearings in forested surroundings, where I saw at least 6 males and females in active display. Sadly my cameras were both wet and my lenses fogged up, so I could not take proper pictures in the field. The abdomen is differently patterned and the hamule differently shaped. James Holden had already found this species during the weeks preceding my visit to Cat Tien and I only relocated it on the last day of my visit, but it was worth the search! Males and females would perch in pairs or would dance around each other in the air in hover flight.

The discovery of such a striking species of Libellulid in Vietnam is pretty amazing. Subsequently it was also found in Thailand. It is similar in appearance to L. elegantissima, which occurs in the extreme north of Vietnam and northward has been recorded from Japanese islands close to Taiwan, like Ishigakijima, from Taiwan itself and from mainland Chinese provinces like Guangdong and Guangxi, but also from Thailand and Cambodia. 

Lyriothemis pallidistigma, male (right) and female (left)

Lyriothemis pallidistigma, male

Even foggier, Lyriothemis pallidistigma, female

Scan of dorsal side of male (top) and female (bottom). Note the differences in color of pterostigmata, the pale stigma of the male rare in Lyriothemis.

Details of hamule and genital lobe