A new study of over 2,000 insect species reveals that many tropical insects, particularly in the Amazon, may struggle to adapt to rising temperatures. Researchers highlight limited heat tolerance in lowland species, potentially disrupting ecosystems. The findings, published in Nature, underscore vulnerabilities in regions with high biodiversity.
Researchers from institutions including Julius-Maximilians-Universität Würzburg and the University of Bremen have analyzed the heat tolerance of more than 2,000 insect species, focusing on areas in East Africa and South America. Data collection occurred in 2022 and 2023 across elevations from cool mountain forests to hot tropical rainforests and lowland savannas. The team also examined genomes to assess protein stability, which influences thermal adaptation.
The study indicates that while some insects at higher altitudes can temporarily increase their heat tolerance, many in tropical lowlands lack this capability. Dr. Kim Holzmann, a researcher at the Chair of Animal Ecology and Tropical Biology at Julius-Maximilians-Universität Würzburg, stated, "Current evaluations of the heat tolerance of insects such as moths, flies, and beetles paint a differentiated -- and at the same time alarming -- picture."
Insects comprise about 70 percent of known animal species, with the majority in tropical regions. Dr. Marcell Peters, an animal ecologist at the University of Bremen, noted, "Rising temperatures could have a massive impact on insect populations, especially in regions with the world's highest biodiversity. Since insects fulfill central functions in ecosystems as pollinators, decomposers, and predators, there is a threat of far-reaching consequences for entire ecosystems."
Variations in heat tolerance among insect groups stem from the conserved structure and thermal stability of their proteins, which evolve slowly. Holzmann added, "If global ecosystems continue to warm unabated, expected future temperatures will lead to critical heat stress for up to half of the insect species there," referring to the Amazon region. The research, supported by the German Research Foundation, was published in Nature in 2026.
