Plants can camouflage odours to avoid being eaten

PARIS: Plants in dense tropical forests are able to mask their chemical scents in order to avoid being detected and eaten by insects — a key advantage in the “information arms race” between themselves and plant-eating herbivores, according to a new study. International researchers from Europe and North America examined 28 species of insects and 20 plant species in Chamela-Cuixmala, a tropical forest reserve on the western coast of Mexico. Their research — published Thursday in the journal Science — sheds light on how individual members of “complex plant communities” evolve to emit similar odours, a pack mentality that keeps them alive and confuses hungry herbivores. “Easily distinguished odours are to the herbivores´ advantage and plants´ disadvantage,” said Professor Phil Stevenson, a researcher at Britain´s Royal Botanic Gardens, Kew. “So, we have an information arms race. Plants want to avoid being located and eaten so do their best to smell like other plants. Thursday´s study was the first time scientists were able to analyse the interactions between such a wide variety of plants and insects, lead author Pengjuan Zu at Massachusetts Institute of Technology said. Previous attempts to understand the cat-and-mouse evolution game between plants and insects relied on the study of only individual plant species in controlled environments.