Netherlands nature update: Pyjama shield beetle spreads north and balloon spider webs blanket wood piles

Franke van der Laan of Stichting MEERgroen reports that the Pyjama shield beetle (10‑12 mm) is becoming common in the Dutch dunes as warmer climates allow it to expand northward. The beetle feeds on the sap of umbellifers such as wild carrot, parsnip, and angelica, and releases an unpleasant odor when disturbed, deterring predators.

In a separate nature note, forest ranger Frans Kapteijns explains that the abundant white silk strands seen on wood chips and low vegetation are produced by balloon spiderlings. The tiny spiders use silk parachutes to drift on rising warm air, a behaviour that peaks in autumn but can start as early as June. The webs serve as protective shelters for the larvae as they await better conditions.

Both observations highlight how climate change and seasonal patterns influence the distribution and behaviour of insect species in the Netherlands.