The amazing Colorado potato beetle amaze friends and foes (and all the scientists) by completely smashing its muscles in the winter

However, in the spring, the beetle rises again without difficulty. What’s wrong with that?

Many animals try to save energy in the winter, when there is little food available. Some even go into hibernation, which leads to a completely reduced metabolism. The Colorado potato beetle is taking a winter vacation, too. But this insect has found a very special way to save as much energy as possible. One that researchers did not anticipate beforehand, writing it in a prestigious journal PNAS.

More about the Colorado potato beetle
The Colorado potato beetle (Leptinotarsa ​​decemlineata) is a beetle in the leaf beetle family. They can be about an inch long and have a beetle-like appearance due to their round, round body. However, the Colorado potato beetle has no points, but is equipped with five black stripes on each of the elytra, which are yellow to yellow-orange in color. The species was originally found only in southern North America. But since 1850, the beetle has traveled with the potato plant, allowing it to spread over a large part of the world. There are no natural enemies in newly colonized areas, so the Colorado potato beetle can multiply very quickly there. Beetles can be a formidable pest in these areas, among other things, to potato cultivation.

During hibernation, the animal’s metabolism slows down to a very low level. How? This is due in part to a change in the way mitochondria – the power plants in cells – work. “They slow down their metabolism by decreasing their mitochondrial function,” explains researcher Brent Sinclair. “So we thought the lower metabolic rates of the Colorado potato beetles must be related to this.”

He went
The researchers conducted an experiment to test this theory. But when the researchers took a closer look at the beetles, they found not a single mitochondria in their flight muscles. “None of them, really,” researcher Jackie Lipinzon recalls. “At first we thought that our machines were not working, or that we were somehow destroying the mitochondria. Finally, we used an electron microscope to study the muscle cells better. Then we found that almost all of the mitochondria were gone.”

People
In human muscle, mitochondria are degraded when they are not used. We see this happen, for example, with astronauts who spend a significant amount of time in weightlessness in space. Then the muscles must be trained to stimulate accumulation.

Colorado potato beetle sitting on a potato plant. Photo: Jackie Lebenson

The Colorado potato beetle is a little different. When the beetle goes into hibernation, it alone breaks down the mitochondria in its flight muscles. In this way, the beetle is able to save a lot of energy during the harsh winter climate. But unlike humans, where it can take a while for mitochondria — and thus muscle mass — to return, it turns out that the mitochondria in the Colorado beetles had all grown back by the end of winter. And that without the beetles being tense in their muscles.

Demolition and construction
So it appears that the Colorado potato beetle is capable of completely smashing its muscles. At the same time, towards the end of winter, beetles can also restore their muscles just as easily. “This ability is completely new to science,” Lipinzon said. “It explains how the beetles save energy during the winter, but take off again in the spring without any problems.”

The team doesn’t yet know if all hibernating insects like the Colorado potato beetle use the same trick to save energy. Future research should show this. However, the discovery shows that some insects are able to regulate their own mitochondria. More insight into this could offer a solution to treat some muscle ailments.