Science

Study finds good reasons to go after your comrades—and some bad ones, too

BY JACK TAMISIEA
Jay Rosenheim had no idea his team’s plan to protect California’s cotton fields would lead to an explosion of cannibalism. Faced with ever-destructive cotton aphids—a tiny ravenous green insect that sucks sap from crops, leaving behind moldy waste and a slew of deadly viruses—he and his colleagues decided to sick another group of insects on them: a stout group of native aphid assassins known as big-eyed bugs.

It worked—for a while. Then, as space became scarce on the plants, something unexpected happened: The big-eyed bugs stopped attacking the aphids and began to hunt one another, devouring hordes of their own eggs. They “became wildly cannibalistic,” says Rosenheim, an entomologist at the University of California, Davis.

Eating your own kind is fairly common throughout the animal world, from single-celled amoebas to salamanders, he and his colleagues report in a new review in Ecology. But not as many species snack on their brethren as one might expect—and the team has detailed the reasons why.

Read on: https://www.science.org/content/article/why-some-animals-turn-cannibal?et_rid=389253831&et_cid=43