Beans use the immune system to attract caterpillars

At the same time, plants that could not detect the molecular signal of caterpillar larvae were largely ignored by wasps. However, they were not without protection. “There are some papers that show if you take away all the immune signals, the worms grow twice as big—they get bigger,” says Steinbrenner. This, he says, shows that the immune system had other ways of keeping wild animals like caterpillars at bay.

Plant protection methods

While the team linked the broken inceptin receptor to the intact signal, the exact mechanism of the immune system is not fully understood. The authors suspect that the recognition of the caterpillars they saw piggybacks on all of the plant’s wounds, which can trigger internal alarms known as damage-associated molecules, or DAMPs. Exactly how the initial activation of receptors translates into the production of volatile organic compounds remains a mystery.

Another caveat lies in choosing an attacker. The Spodoptera exiguaAlso known as the beet armyworm, it is a herbivore, which means it eats a variety of plants and likes to be protected by plants. Special herbivores can adapt their metabolic processes to reduce or bypass the chemical defenses of their hosts. In this study, the researchers admit that we still don’t know if a functional inceptin receptor provides greater resistance, or if specific parasites can fool these alarms.

Finally, in an experiment in the Oaxacan field, the team showed that carnivorous wasps use atmospheric problems to find their prey, but the importance of direct protection of the leaf against direct wasp recruitment is not clear. In their future research, scientists want to investigate this in more detail. However, the group believes that their work will help protect crops such as beans from pests.

“Today, we do it with chemicals, with pesticides, but if we can use a better and more stable receptor from more plants, maybe we can provide protection against pests or pathogens in some way,” says Steinbrenner. “That’s the big picture, the long-term goal of our lab.”

Advanced Science, 2026. DOI: 10.1126/sciadv.aec3229