2025 there were fewer wasps than the previous year
This year there are fewer wasps than last year, which was pleasantly noticeable when eating outdoors. The reasons for this are not entirely scientifically clarified, reported ORF Upper Austria. "After a strong wasp year, a weak one usually follows - this has been shown again this year," explained insect expert Martin Schwarz from the Biodiversity Center Upper Austria. It is suspected that after an especially intense year, wasps strongly compete with each other.
This would lead to fewer young queens being produced, who would establish new colonies the following spring. "This spring I saw very few wasp queens. That certainly has something to do with last year," said Schwarz on ORF. The cool and rainy weather in spring and summer was not so decisive this year, although the weather itself does play a role, as Schwarz explained to the APA.
Dry and warm is optimal for wasps
Moist-cool weather in winter is bad for wasps, while dry or even cold weather with a snow cover is very good. Also in spring, "when the young queens leave their winter hiding places and want to establish a colony - each on their own - dry, warm weather is optimal," said the expert. In wet-cold weather, however, wasps cannot fly much. Food and diseases also play a role.
Few wasps mean "very generally speaking," more flies. Wasp larvae are fed with animal prey - including many insects. "If there are fewer wasps, they naturally catch fewer flies, then the flies simply do better," explained Schwarz. But of course, other aspects also come into play regarding the fly population.
Expert expects "a bit more" wasps in 2026
For the coming year, Schwarz expects "a bit more" wasps, although the development of the colonies is also influenced by the weather. Cool and wet weather promises smaller nests, warm temperatures larger nests and colonies of several thousand animals. The distribution among wasp species must also be considered: If there are many hornets, this means fewer other wasps.
(APA/Red)
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