Venus flytrap trigger hairs are micronewton mechano-sensors that can detect small insect prey

Abstract

Venus flytraps detect moving insects via highly sensitive, action potential (AP)-producing trigger hairs, which act as high-sensitivity levers, crucial for prey capture and digestion. Controlled stimulation revealed that they can trigger APs for deflections >2.9°, angular velocities >3.4° s^-1 and forces >29 µN. Hairs became desensitized and subsequently responded to fast consecutive stimulations; desensitization increased at lower temperatures. Recording of ant trigger hair contact events revealed that even small insects exceed the hairs' sensitivity threshold.