Species composition and seasonal occurrence of odonates in Lake Izunuma-Uchinuma and the surrounding areas, Miyagi Prefecture, Japan

Abstract

Seasonal changes in species composition and abundance of odonate adults were investigated in Lake Izunuma-Uchinuma and the surrounding areas, northeastern Miyagi Prefecture, Japan, from May through October 2014. Thirty-five species and 6,802 individuals belonging to ten families of odonate adults were observed during the study period. The species richness and abundance of odonates were high from June to September and peaked in July. The dominant species were Deielia phaon and Paracercion hieroglyphicum in June and July and then shifted to Sympetrum infuscatum and S. frequens during August to October. The four dominant species, D. phaon, P. hieroglyphicum, S. infuscatum and Ischnura asiatica accounted for 73.7% of the total observed adults. The endangered species such as P. plagiosum represented two or lower percentage of the observed individuals, suggesting the importance of conservation for these endangered species.