Until now, little was known about how plants protect themselves from plant-eating insects and how the arms race between insects and plants unfolded. Researchers from Wageningen University & Research have gained more insight into this: strong leaf necrosis—the mechanism by which plants detect and kill the eggs of butterflies and other insects on their leaves—emerged almost exclusively in cruciferous plants and their wild relatives that were attacked by cabbage whites who had developed immunity to the plants' toxic mustard oil. A publication on this subject appeared in the journal New Phytologist.
source https://phys.org/news/2021-02-cabbage-whites-triggered-egg-killing-leaf.html
