Rising cost of living for insects: Energy demand increases with climate change

The animal project team members: Field wasps of the species Polistes biglumis from the Alps sharing prey and cooling the nest with drops of water. Polistes dominula from the Austrian and Italian lowlands and Polistes gallicus from Italy were also recruited. Photo: Uni Graz/Stabentheiner

It sounds paradoxical: when the climate gets warmer, insects need more energy. Biologists at the University of Graz have demonstrated this using the example of paper wasps of the genus Polistes. Their mated queens spend the cold season in hidden winter quarters and live on the reserves built up in autumn. "A special metabolic characteristic of insects is that their energy requirements increase exponentially at rest as the outside temperature rises," says Anton Stabentheiner, lead author of the study, which was recently published in the Journal of Comparative Physiology B.

"If the energy requirements of insects increase due to warm weather during hibernation, this can lead to premature depletion of their reserves. This means that they have to obtain more food in summer to make up for this deficit, both for their own metabolism and for rearing their offspring," explains Anton Stabentheiner.
The results of the study include concrete figures: "Our investigations suggest that a temperature rise of two degrees Celsius would result in a 26 to 33 per cent higher energy requirement just for hibernation," reports Helmut Kovac, co-author of the publication. For the summer season, the biologists expect an increase of 12 to 24 per cent.
The latest research has shown that although the paper wasps could maintain their basic metabolism for an entire summer with the energy reserves remaining in spring, the daily flight times for nest building and foraging would be limited to a few hours. Detailed measurements show: "The fat reserves could still be sufficient for new nest building even in climate scenarios of two degrees of warming and more. However, the carbohydrate and sugar reserves, which are more depleted after a warm winter, pose a major problem. This is because a basic supply of sugar is essential for many metabolic functions, for example in the nervous system and in the muscles," the scientists explain.
The study therefore proves that, in addition to shrinking habitats and pesticides, climate change is also making life difficult for insects.

In addition to the project leaders Helmut Kovac and Anton Stabentheiner, the research team of the Eco-Physiology and Eco-Ethology working group also includes Helmut Käfer, Edith Stabentheiner, Regina Willfurth and Astrid Bay Amstrup.

Publications
Stabentheiner et al.: The costs of overwintering in paper wasps (Polistes dominula and Polistes gallicus): the use of energy stores. Journal of Comparative Physiology B (2024).
https://doi.org/10.1007/s00360-024-01540-w

Kovac et al.: The Impact of Climate on the Energetics of Overwintering Paper Wasp Gynes (Polistes dominula and Polistes gallicus). Insects (2023).
https://doi.org/10.3390/insects14110849

Gudrun Pichler

Related news

Learning better: Can science experiments in group settings help children with autism?

How can pupils with autism spectrum disorder (ASD) have positive learning experiences and improve their social skills? Researchers at the University of Graz are investigating how science experiments in group settings can contribute to this. Initial results from the project, which is funded by the Austrian Science Fund FWF, show that children react differently depending on the kind of neurodiversity, but that experimentation classes with the right setting definitely have potential. "Pupils with ASD can do more than is currently expected of them in many cases," says project leader Uwe Simon.

Sustainability Award 2024 for two projects of the University of Graz

How do major international conferences reduce their carbon footprint? And what can maths lessons contribute to education for sustainable development? Two questions that were answered at the University of Graz. The corresponding projects were awarded the Sustainability Award 2024 in silver on 26 November in Vienna. This award for Austria's universities and colleges is presented by the Ministry of Science and the Ministry of Climate Protection.

Bees under observation: University of Graz provides unprecedented insights into the hive

What is going on in the combs? How many eggs is the queen laying? How much honey is there? Autonomous robots and AI algorithms provide important data and high-resolution real-time images from inside a beehive. "As part of an international team, we have developed a game-changer technology for a new type of digitalised behavioural research," reports biologist Thomas Schmickl from the Artifical Life Lab at the University of Graz. The publication, which has just appeared as the cover story in the journal "Science Robotics", describes the wealth of information that can be obtained from this unique research facility.

Research for healthy aging: FWF funds Cluster of Excellence "MetAGE" with 18 million euros

Six researchers from the Field of Excellence "BioHealth" at the University of Graz, together with colleagues from the Medical Universities of Graz and Vienna, have acquired an FWF-funded "Cluster of Excellence". Now a newly formed center of excellence will be created under the leadership of the University of Graz. The aim is to gain a better understanding of healthy aging. The findings will flow directly into clinical research.