Scientists Finally Understand How Beetles "Drink" Water Through Their Rear End

Beetles are world champions at surviving in extremely dry environments. A trait that is partly due to their ability to suck water out of the air through their rear end. A new study from the University of Copenhagen explains how this is possible. Knowledge that can be used in the future for more targeted and gentle control of global pests such as the grain weevil and the red flour beetle.

The Challenge of Crop Pests

Pests eat their way through thousands of tons of food every year around the world. Particularly in developing countries, food security is affected by animals such as the grain weevil or the red flour beetle, which have specialized over thousands of years to survive in extremely dry environments such as grain stores.

Up to 25% of global food production is lost to pests annually, making effective pest control crucial for food security. However, conventional pesticides harm beneficial organisms and damage the environment.

Revolutionary Research Findings

Therefore, researchers from the Department of Biology at the University of Copenhagen have investigated the deeper physiological processes in beetles that enable them to survive completely without drinking liquid water. One of the secrets behind this ability is found in the beetle's rear end.

The Science Behind Water Absorption

Beetles are able to open their rectum and through that route absorb humid air and convert it to liquid that they can absorb into their body. A different way of taking in water, which has been roughly known for a good 100 years in research environments worldwide, but which has not been fully illuminated until now.

"We have shed new light on the molecular mechanisms in the beetle that enable it to absorb water rectally. Insects are particularly sensitive to changes in their water balance, and therefore this knowledge can be used to develop more targeted methods to control beetles that destroy our food production without killing other animals or destroying nature."

— Kenneth Veland Halberg, Associate Professor, Department of Biology

Key Scientific Discoveries

Leptophragmata Cells - The Water Harvesting System

Our research team identified a gene that was 60 times more highly expressed in the beetle's rear end compared to the rest of the animal - higher than any other gene we found. This led us to a special group of cells called leptophragmata cells, which play a crucial role when the beetle absorbs water through its rear end.

"Leptophragmata cells are tiny cells that sit like windows between the beetle's kidneys and the beetle's circulatory system. As the beetle's kidneys surround its hindgut, the leptophragmata cells function by pumping salts into the kidneys so that they are able to harvest water from the air from the beetle's rear intestine and further out into the blood through osmosis - and that's new knowledge for us," explains Kenneth Veland Halberg.

Extreme Efficiency

The beetle can go through an entire life cycle without drinking liquid water, thanks to its highly specialized intestines and rear end being optimized for extracting water from food and air. In fact, this happens so efficiently that the fecal samples we examined were bone dry and completely without water.

Even a dry grain, which perhaps consists of 1-2 percent water, the beetle can utilize in its water balance.

Implications for Sustainable Pest Control

This fundamental understanding opens new possibilities for developing targeted, environmentally friendly pest control methods.

The Path Forward

"Now we understand exactly which genes, cells and molecules are at play in the beetle when it absorbs water in its hindgut. This means that we suddenly have a way to disrupt these very efficient processes by, for example, developing insecticides that target that function and thereby kill the beetle," says Kenneth Veland Halberg.

Benefits of Targeted Approaches

• Species-specific targeting - affects only harmful beetle species
• Preserves beneficial insects and ecosystem health
• No environmental contamination from persistent chemicals
• Reduces resistance development through novel mode of action

About the Research

Methodology

The researchers used the red flour beetle as a model organism because it has a well-sequenced genome and allows the use of a broad spectrum of genetic and molecular biological tools. The findings apply to many beetle species that affect food security.

Global Impact

• Grain weevils, rice flour beetles, potato beetles and other types of beetles and insects make annual inroads into up to 25% of the global food supply
• Particularly in developing countries, insects are a major problem because they lack access to effective pest control
• The project was carried out in collaboration with researchers from the University of Glasgow and the University of Edinburgh in Scotland

The Bigger Picture

Insect Biomass and Ecosystem Importance

"Insect biomass on earth is twenty times larger than humans'. They have enormous significance for our ecosystems and our health. Therefore, we need to understand them," concludes the researcher.

500 Million Years of Success

Beetles have successfully spread across the entire Earth over the last 500 million years, so every fifth animal species today is a beetle. Unfortunately, beetles are also among the pests that affect food security.

Future Applications

This research forms the scientific foundation for Yngvi Bio's protein-based pest control technology. By understanding the precise molecular mechanisms of beetle physiology, we can develop targeted interventions that:

1. Disrupt specific physiological processes in pest species
2. Maintain ecological balance by preserving beneficial insects
3. Provide sustainable alternatives to chemical pesticides
4. Support global food security through effective, environmentally safe solutions

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Research Publication: This study was published in the scientific journal PNAS (Proceedings of the National Academy of Sciences).

Research Team: Kenneth Veland Halberg (University of Copenhagen), in collaboration with researchers from the University of Glasgow and University of Edinburgh.

For more information about how this research translates into practical pest control solutions, explore our [technology platform](/technology).