Using the sophisticated ‘nose’ of caterpillars to lure them away from crops

About the episode

A caterpillar’s life is full of threats. They are seen as a delicacy by many other animals and plants have all kinds of strategies and substances to ward off the always hungry caterpillars.

As a caterpillar, it is therefore necessary to keep a close eye on the environment while eating all that. They do this with the help of their antennae, which serve as a kind of nose. Scientists from Wageningen have zoomed in closely on this part of the body.

Take, for example, the antenna of the Greater Cabbage White. This contains only 34 neurons in the caterpillar, but 300,000 neurons when the insect lives as an adult butterfly.

That’s quite a difference. Yet the functioning of both olfactory organs appears to be equally complex. Both use special proteins that bind to chemicals in the environment. If such a substance is noticed, an electrical signal is sent to the brain area that calculates which odor it is.

Understanding how this works in the caterpillars can be extremely useful for protecting crops. For example, this specific animal is capable of endangering an entire cabbage crop.

Before you think about toxic pesticides: the researchers think that this actually offers a way to do it without harmful substances. For example, the behavior of caterpillars could be influenced by growing caterpillar-repellent plants between cabbage crops. By then using attractive plants in other places, you could lure caterpillars away from the crops.

But for such a chemical-free strategy to work, you first have to find out exactly what insects can smell.

Read more about the research here: ‘Caterpillar noses’ turn out to be surprisingly advanced