PARENT SESSION
Contributed Oral Session 144: Predator - Prey Ecology: Terrestrial Habitat and Food Webs
Thursday, August 11, 1:30 PM - 5:00 PM, Meeting Room 524 A, Level 5, Palais des congrès de Montréal

Associational resistance and susceptibility: Are they multitrophic phenomena ?

Barbosa, Pedro¹, Caldas, Astrid¹, ¹ Department of Entomology, College Park, MD, USA

ABSTRACT- Most plants are subject to herbivory. Animals, at some point in their lives are prey for natural enemies. Thus, for both plants and animals, traits, behaviors and interactions that reduce susceptibility to their natural enemies are critical determinants of fitness. Research on plants has demonstrated that susceptibility of any given plant to herbivory is strongly influence by the traits of nearby individuals of other plant species. This community-level determinant of susceptibility has been described as associational resistance and associational susceptibility. Although these phenomena have been associated with plant communities, they have not been considered for animal communities or assemblages. We propose that co-occurring herbivore species mutually influence resistance or susceptibility to species in the third trophic level, i.e., predators, pathogens, and parasitoids. In this study, we demonstrate that caterpillars representing seven families and 82 species share traits that enhance or reduce the probability of parasitism and thus may provide associational resistance or susceptibility, depending on the other species with which they co-occur.

Key words: caterpillars, parasitoids, susceptibility to parasitism, resistance to parasitism