Variation in Escape Behavior of Red and Green Clones of the Pea Aphid

Many insect species have evolved a number of antipredator tactics among which the animal can choose when attacked by a natural enemy. While it is known that individuals may differ in how the antipredator tactics are employed, quantitative studies are rare. In the pea aphid, it has been suggested that different clones differ in their propensity to escape from a predator and that this propensity is linked to the body color of the aphid. We tested clonal variation in the escape behavior in red and green clones of the pea aphid. In three experiments the responses of clones to artificial stimuli and a natural predator were quantified. The results indicate that (1) clones differ considerably in their propensity to show escape behavior, (2) red clones are more likely to drop off the host plant when subjected to an artificial stimulus than green clones are, and (3) the patterns of clonal variation in the escape behavior were not consistent through all three experiments, as clones did not differ in their behavior when attacked by a real predator. The differences in the responses of a clone toward different stimuli supposed to mimic predator attack suggest that extrapolating from laboratory experiments to a field situation may be difficult.