Experts concerned about low insect numbers in the Netherlands

The spring and summer is usually a time when the Netherlands sees hoards of butterflies, snails, mosquitoes and other creepy crawlies. However, this year, insects have been rather absent, which concerns experts.

Declining insect numbers in the Netherlands

The spring of 2025 was the driest ever recorded in the Netherlands, and this has had an impact on the insect population. Many insects rely on rain for moisture, breeding in puddles or as a food source. 

A lack of insects roaming around our gardens or buzzing around our homes is a sign of the drop in their numbers. The absence of mosquitoes is a notable example, as they breed in even the smallest of puddles. With the drought, there are fewer mosquitoes, which could affect other species of insects and animals that rely on mosquitoes as a food source, such as wasps.

As an indicator species, butterflies give experts a good idea of how the ecosystem is doing, and the majority of them are struggling. According to Statistics Netherlands (CBS) and the Butterfly Foundation, butterfly populations in the Netherlands more than halved between 1992 and 2023.

"It says something about the entire insect kingdom,” Wageningen University professor of entomology Marcel Dicke told AD. “I see very few butterflies flying. You can only conclude that they are going through a particularly tough time."

Why are declining insect populations so concerning?

At first, it may seem like a positive thing that there aren’t as many insects eating your plants in the garden or flying around while you’re enjoying food on the terrace, but according to Dicke, it should concern us. "Insects are the organisms that keep the world livable for us. They are our hosts on this planet. They are at the base of the food chain, they help pollinate plants, and they clean up waste,” he explains.

While it may rain again and insect populations can recover somewhat, other human activities continue to harm their numbers. Scientists are concerned about pesticide use in agriculture and the habit that Dutch residents have of paving over their gardens. “But I don't see the use of pesticides decreasing. And many more people could fill their gardens with native flowering plants."