An electronic nose that smells plants’ pain

It turns out the best way to hear a plant scream is to smell it.

Scientists are using an electronic nose tailored to eavesdrop on plants that have been damaged or are under attack. The nose successfully discriminated among the various distress signals different plants emit, depending on the pests plaguing them — discerning, for example, a tobacco hornworm attack from assault by powdery mildew.