Individual and geographic variation in Coenagrion glaciale (Selys, 1872), with description of a new subspecies (Zygoptera: Coenagrionidae)

Coenagrion glaciale glaciale (Selys, 1872) (syn. Agrion tugur Bartenev. 1956) is redescribed and a description is given of C. glaciale orientale ssp. n. ( <S holotype: Monkhukhay River, Primorye, USSR, May 26, 1962; 9 allotype: the same locality, June 1, 1962; both in the collections of the Institute of Biology of the USSR Academy of Sciences, Novosibirsk). In both sspp. a number of aberrant specimens were encountered; these are described under the names C. glaciale glaciale f. pallida and C. glaciale orientale f. fusca. Some speculations are offered concerning the origin of the two -sspp. and their aberrant forms.