Beitrag zur Kenntnis der Biologie von Nehalennia speciosa (Charpentier, 1840) (Zygoptera: Coenagrionidae)

Observations on the development of the body coloration in the course of maturation, on the population structure and on various behavioural elements, carried out at the lake Liitzelsee nr. Hombrechtikon, Kanton Zurich, Switzerland, are brought on record. All females turn orange brown after a period of homeochromic coloration.