Escape responses of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae): influence of predator type and temperature

Abstract

The escape responses exhibited by pea aphids were examined at three different temperatures, 15, 20, and 25 °C, using two different predators: syrphid larvae and coccinellid beetles. Coccinellid beetles foraged more vigorously at higher temperatures resulting in greater vibrations on the host plant as they searched for aphids. Foraging rates for syrphids were slower by comparison and did not vary with temperature. We found that most aphids dropped off the host plant when confronted by coccinellid beetles, especially at higher temperatures, and backed up when confronted by syrphid larvae regardless of temperature. We conclude that individual aphids do not have characteristic escape responses, but rather the response adopted depends in part on the foraging rate and species of predator.