Two Thousand Tropical Insect Species Threatened with Extinction Due to Failure to Adapt to Heat
A comprehensive study of more than 2,000 insect species reveals a harsh reality: many insects are far more vulnerable to rising temperatures than previously thought. The research, published in Nature, shows that lowland tropical regions, home to the world’s highest biodiversity, are particularly lacking in the temperature flexibility of insects.
This fragility raises major concerns for ecological balance. As pollinators, decomposers, and predators, insect vulnerability is predicted to trigger domino effects that could disrupt ecosystems globally.
Funded by the German Research Foundation, the study found striking differences in how insects respond to heat. Dr Kim Holzmann, a researcher at Julius-Maximilians-Universität Würzburg (JMU), explains that current assessments of insect heat tolerance, including moths, flies, and beetles, paint a worrying picture. “While species at higher elevations can increase their heat tolerance, at least in the short term, many lowland species largely lack this capacity,” Holzmann said.
In other words, insects living in tropical rainforests do not have a “safe space” to adapt when environmental temperatures continue to rise.
Why is adaptation difficult? The researchers found that heat tolerance is closely tied to the structure and thermal stability of proteins within the insects’ bodies. These traits appear to be deeply rooted in the evolutionary tree of the insect family and cannot be quickly adapted to new climatic conditions.
Dr Marcell Peters, an animal ecologist at the University of Bremen, explains that the fundamental traits of heat tolerance have biological roots and cannot adapt rapidly to new climatic conditions. “Temperature increases could have massive impacts on insect populations, especially in the world’s most biodiverse regions. Because insects play central roles in ecosystems as pollinators, decomposers, and predators, there are threats to entire ecosystems,” Peters emphasises.
Field data collected during 2022 and 2023 in East Africa and South America indicate a bleak prognosis, particularly for the Amazon region. “If global ecosystems continue to heat up unchecked, future temperatures are expected to impose acute heat stress on up to half of tropical insect species there,” Holzmann says.
Given that insects account for around 70 percent of all animal species known to humankind, their failure to adapt is not merely a minor biological issue but a real threat to the foundation of life on Earth.