Bug Attack Triggers Defense In Plants

Radishes attacked by chewing insects early in the growing season defend themselves by making a spicy sap that later predators don’t like and will avoid, according to a study that may influence the use of pesticides.

Researchers at the University of California, Davis, report in the journal Science that plants chewed on by a caterpillar shortly after sprouting went on to make more seeds than plants that escaped the early attack.

Meanwhile, aphids, earwigs and leaf flea beetles - all garden pests - feasted on nearby plants that hadn’t been subject to the caterpillar.

Anurag Agrawal, lead author of the study being published today, said the research proves that plants actually benefit when their natural defenses against insects are turned on early.

“This tends to protect them from later predation,” he said.