Aeshna vercanica sp. nov. from Iran with a new insight into the Aeshna cyanea-group (Odonata: Aeshnidae)

Aeshna vercanica sp. nov. is described and illustrated. The male holotype and four male paratypes were collected on 15-vii-2013 in the Hyrcanian forest of the Alborz Mountains, Mazandaran province, northwestern Iran. A specimen collected on 29-vi-2002 in the Talysh Hills, Lankoran area, Azerbaijan, also belongs to the new species. In July 2014 the species, including females, was recorded again at the type locality and additionally ca 400 km further east in Golestan province. Males are similar to Aeshna cyanea in the structure of genitalia and terminalia but differ in head morphology, pterostigma length, colour pattern, and behaviour. Females have small abdominal blue or turquoise postero-median dorsal spots which are absent on S9 and S10, thin green antehumeral stripes, a less robust appearance than females of A. cyanea, and are more slender and longer. The range of A. vercanica sp. nov. covers the Hyrcanian forest along the southern margin of the Caspian Sea. Analysis of the barcoding COI sequence of DNA confirmed that A. vercanica sp. nov. is separated from A. cyanea by a genetic distance of ca 4%. The ITS gave a similar result. A haplotype map could not derive A. vercanica sp. nov. directly from A. cyanea. They are thus related but different species, and we suggest the common ancestor lived in pre-Pleistocene times. Analysis of A. cyanea specimens from across its range also revealed a western clade from the Maghreb to Central Europe. Populations from the Caucasus to Eastern Europe were polytomous, a common scenario for post-glacial invaders. A molecular comparison of the species pair A. juncea and A. subarctica showed these to be even more closely related than A. cyanea and A. vercanica sp. nov.