The karyotype of Ischnura pumilio (Charp.) (Zygoptera: Coenagrionidae)

Miss M. Verdonk (Bussum, the Netherlands) during 1978 studied a population of this species in the surroundings of the village of Winterswijk, Gelderland Prov., the Netherlands, and supplied two adult males (taken July 23, 1978) for cytological examination. This is the thirteenth member of the genus examined karyologically, and the first possessing a high-n complement, viz 2n d = 29, n à — 15. The mitotic and meiotic metaphase sets have the definite appearance of a primary complement, without any trace of a secondary fragmentation of a pair having taken place. The elements (bivalents) are of gradually decreasing magnitude, save for a mediumsized m and a slightly smaller (unpaired) X.