In Middle Asia, the dragonfly Pantala flavescens makes regular seasonal migrations. In spring, sexually mature dragonflies (immigrants) arrive in this region for reproduction. Dragonflies of the aboriginal generation (residents) develop in about two months, and migrate south in autumn. Residents of Middle Asia have significantly lower δ2H values (−123.5 (SD 17.2)‰, n = 53) than immigrants (−64.4 (9.7)‰, n = 12), as well as aboriginal dragonfly species from Ethiopia (−47.9 (10.8)‰, n = 4) and the Sahel zone (−50.1 (15.5)‰, n = 11). Phenological data on P. flavescens in the Afro-Asian region and a comparison with published isotopic data on migratory insects from this region suggest that (i) the probable area of origin of P. flavescens immigrants is located in tropical parts of East Africa and/or the Arabian Peninsula and (ii) the autumn migration of Middle Asian residents to the south may also pass through the Indian Ocean. We assume that in the Afro-Asian region, there is an extensive migration circle of P. flavescens covering East Africa, Central Asia and the Indian subcontinent with a total length of more than 14,000 km.
Migrations of dragonflies in Chokpak Pass of the Western Tien Shan (42.530°N, 70.605°E) were studied using large bird traps of the Rybachy type, which proved to be very efficient for recording these insects. The obligatory southward autumn migrations were proved for Sympetrum fonscolombii and Anax parthenope, and supposed for Hemianax ephippiger, which is a rare species in this region. The autumn movement from the mountains to plains was recorded for the species characterized by seasonal vertical migrations: Sympetrum arenicolor, S. striolatum pallidum, and Aeshna mixta. The cold air fronts increase the intensity of flights.
1 December 2019 in Euroasian Entomological Journal