Firefly flashing and jumping spider predation

► We tested whether firefly flashing serves an antipredator function against diurnal jumping spiders (Phidippus sp.). ► Spiders and fireflies interacted at dusk, and adult fireflies flashed when disturbed during the day. ► Spiders attacked prey placed near a flashing light more often than prey placed near a light that was always off or on. ► Spiders avoided unpalatable prey associated with a flashing light after seven encounters.