Warm-adapted insects benefit from climate change

A new study led by the Technical University of Munich (TUM) has investigated how climate change is impacting insect populations across Europe. The experts found that species adapted to cooler temperatures, such as Thor’s fritillary, the green mountain grasshopper, or the white-faced darter, are declining. Meanwhile, warm-adapted species like the scarlet dragonfly, the European tree cricket, or the baton blue butterfly are in fact thriving as global temperatures rise. These findings highlight the complex relationships between climate change and various animal species, suggesting that, for some animals, global warming could actually turn out to be beneficial.

By using data on current population trends of more than 200 species of insects in Bavaria, including 120 butterflies, 50 orthoptera, and 60 dragonflies, the researchers found that across all these insect groups, there was an increase in the populations of warm-adapted species and a decline of species adapted to cooler environments.

“We determined the temperature preferences of each species using data on their distribution within Europe and the mean temperature in that area. In other words, species with a primarily northern distribution are cold-adapted species, and species with a primarily southern European distribution are warm-adapted species,” explained study lead author Eva Engelhardt, an expert in Terrestrial Ecology at TUM.

“Our comparisons of the various groups of insects revealed significant differences. Whilst there was more decline than increase in butterfly and Orthoptera species, the trends for dragonflies were largely positive,” she added.

According to the researchers, a possible reason for this is improvements in water quality during the previous decades, a change that has particularly benefited dragonflies, which thrive in a variety of aquatic habitats. On the other hand, species adapted to very specific ecosystems (the so-called “habitat specialists”), including butterflies such as the large heath or the cranberry blue, experienced a marked decline due to climate change.

“Our study highlights the complex effect of climate change on our insect fauna,” said co-author Diana Bowler, a postdoctoral fellow in Ecosystem Services at the German Center for Integrative Biodiversity (iDiv). “Our work is also an example of how modern approaches to data analysis can be used to obtain fascinating results from existing data sets. Volunteer and agency conservation work often does generate the data, but they are rarely evaluated systematically. This should happen much more often through collaborations like ours,” she concluded.

The study is published in the journal Global Change Biology.   

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By Andrei Ionescu, Earth.com Staff Writer