Mededelingen Over een populatie van de Groene glazenmaker in de veenkoloniën en een beschrijving van twee schemervluchten

By accident and with some luck on the fifth of August 1968 a population of Aeshna viridis was discovered in an area called the veenkoloniën near Wildervank in the province of Groningen in the northeastern part of The Netherlands. On August 21, 1968 a twilight flight of a large numbers of imagoes was observed. Both males and females appeared suddenly about five minutes after sunset in a fairly large number (estimated at several hundreds), filling up the sky above the side-canals within a few minutes. After about fifteen minutes all dragonflies disappeared as suddenly as they had appeared. A second twilight flight was observed on July 7, 1970. This observation was earlier published in Dutmer et al. (1973). However, until now these observations of twilight flights of Aeshna viridis are the only one so far described properly in Dutch literature. Twilight flights of dragonflies in general and of Aeshna viridis in particular are most likely overlooked.