Document: IGN-3-56-34

Costs of anti-predator behavior in a forest caterpillar.

CASTELLANOS, I.*, A.KRALJEVIK and P.BARBOSA

University of Maryland, College Park, MD 20742, USA ¹

Abstract:
Predators of Orgyia leucostigma larvae create vibratory signals as they approach caterpillars. Larvae respond to these signals in an assessment of risk of of predation presented by different predators and exhibit appropriate anti-predator behaviors. O. leucostigma caterpillars respond to particular frequency and amplitude components of the substrate-borne vibrations made by active foraging predators. These signals enable caterpillars to distinguish between predators, non-predators such as herbivores, and abiotic factors. The costs of these behaviors under different ecological conditions were measured. Predator avoidance involved falling to the ground. However, larvae are able to orient to trees after dropping and thus reduce the cost of dropping. The highest cost of inducing anti-predator behavior occured when caterpillars fell to the ground on sites with high densities of ground predators.

Keywords: costs, predation, anti-predator behavior, vibratory signals, caterpillars

This abstract is being presented at: 2:15 PM in session:
Oral Session #48: Anti-Predator Responses: Fish to Sagebrush.