Citizen science monitoring schemes: trends in priority butterflies and dragonflies
Through the species monitoring schemes, INBO collects reliable information on priority species in Flanders. These monitoring schemes are a collaboration between INBO, the Nature Agency and Natuurpunt Studie. They rely heavily on citizen science. It is usually volunteers who carry out the counts. The collaboration has been running since 2016 and was recently extended until 2030.
In two recent INBO reports, we present the trends for priority butterflies and dragonflies over the period 2016–2025.
- For most butterflies, we see a decline or sharp decline in abundance. Only the numbers of the gatekeeper remain stable. The sharpest decline is seen in the mazarine blue, of which only a handful of individuals were counted in 2024 and 2025. A ray of hope is the silver-spotted skipper, which has partially recovered following a low point in 2020.
- Among the dragonflies, we see that a few species are making significant progress: the numbers of the lilypad whiteface and the river clubtail are rising sharply. However, the majority of dragonfly species are still in decline. The spotted darter has experienced the sharpest decline, and we fear that the species will disappear from Flanders within a few years.
Toon Westra, Geert De Knijf, Dirk Maes, Sam Van de Poel and Stijn Van Onsem
Read more:
- Westra, Toon ; De Knijf, Geert ; Ledegen, Hannes et al. / Trends op basis van de libellenmeetnetten (2016 - 2025) : Citizen science monitoring in Vlaanderen. Instituut voor Natuur- en Bosonderzoek, 2026. (Rapporten van het Instituut voor Natuur- en Bosonderzoek; 37).
- Westra, Toon ; Maes, Dirk ; Veraghtert, Wim et al. / Trends op basis van de dagvlindermeetnetten (2016 - 2025) : Citizen science monitoring in Vlaanderen. Instituut voor Natuur- en Bosonderzoek, 2026. (Rapporten van het Instituut voor Natuur- en Bosonderzoek; 38).
Image above: river clubtail (photo Robort Pieters)