English abstract

The species monitoring programme meetnetten.be aims at collecting reliable information on priority species in Flanders. It consists of a series of monitoring schemes which were designed by the Research Institute for Nature and Forest (INBO). Species are counted by volunteers in a standardized way under the coordination of the NGO Natuurpunt Studie.

This report shows the results of the dragonfly monitoring schemes for the period 2016 - 2025. In Flanders we see the following trends:

  • a strong increase in abundance of the River Clubtail (Stylurus flavipes) and the Lilypad Whiteface (Leucorrhinia caudalis),
  • a decrease in abundance of the Beautiful Demoiselle (Calopteryx virgo) and the Yellow-spotted Whiteface (Leucorrhinia pectoralis),
  • a strong decrease in abundance of the Spearhead Bluet (Coenagrion hastulatum), the Crescent Bluet (Coenagrion lunulatum) and the Spotted Darter (Sympetrum depressiusculum),
  • an uncertain trend for the Variable Bluet (Coenagrion pulchellum) and the Green-eyed Hawker (Aeshna isoceles).

The strongest decline is observed for the Spotted Darter (Sympetrum depressiusculum). The species is now restricted to only one area in Flanders. Even there, numbers continue to decrease despite targeted management measures. If this trend continues, the species will go extinct in Flanders within a few years.

The numbers of the Lilypad Whiteface (Leucorrhinia caudalis) show the strongest increase. Currently, there is only one population in Flanders, but its distribution is expected to expand in the future.

The results confirm the importance of the dragonfly monitoring schemes for the standardized monitoring of priority species in Flanders. For species showing a strong decline, additional site-specific and management-oriented analysis is required, focusing on the remaining populations and the quality of their breeding habitat The planned adjustments to the monitoring schemes from 2026 onwards should allow for a more accurate monitoring of future changes.

Creative Commons-License Westra, T., De Knijf, G., Ledegen, H., Van de Poel, S. & Onkelinx, T. (2026) 10.21436/inbor.148382180