Het libellenjaar 2006: een overzicht

Here we present the first results of the observations of dragonflies we received for the year 2006 for Flanders. A total of more than 6000 observations, the highest number ever, from 58 species were received. These were collected by 73 collaborators. All geographical regions and 40% of the total number of atlas squares (5x5 km UTM) were investigated. Three species, Ischnura elegans, Anax imperator and Orthetrum cancellatum were seen in more than 50% of the investigated squares. Remarkable was the still going on increase of Calopteryx splendens which was observed in 30% of the squares. Southern species as Erythromma viridulum and Crocothemis erythraea are getting quite common and are among the 20 most reported species in Flanders. Other southern species as Lestes barbarus, Sympetrum fonscolombii, both mentioned in more than 10% of the squares, and Aeshna affinis, Anax parthenope and Orthetrum brunneum were observed at several localities. The decline of some Red List species seems still to be going on. The number of localities for some of them, e.g. Coenagrion lunulatum, Gomphus vulgatissimus, Sympetrum depressiusculum and Leucorrhinia rubicunda has fallen to less than three . They can be considered as becoming extinct in Flanders in the near future if their decline continues.