Revista Chilena de Historia Natural 86 (2): 161-167, 2013
RESEARCH ARTICLE
Evidence for insect seed predator dynamics mediated by vertebrate
frugivores
Vertebrate frugivores have been suggested to reduce seed predation,
indirectly controlling populations of insect seed predators (ISP) by means of consuming many individuals when feeding on
fruits. The possibility has not been explored, however, that this ‘frugivore predation’ may differentially affect ISP according
to species-specific differences in larval development time within the fruit. In the dry tropical forest trees Acacia
pennatula and Guazuma ulmifolia we compared seed predation and the absolute and relative
abundances of bruchid beetle species (Bruchinae) in two sites, one with large frugivores (cattle) and the other cattle-free for
a considerable time. In the site with cattle we found a notable overall reduction in the proportion of seeds predated (ca. 15
%) with respect to cattle-free site, and changes in the ISP community as well, in particular a reduced absolute and relative
abundance of the bruchid species with the longest larval development time. Our results suggest that the interplay between
evolutionary processes (resulting in variation in insect life-histories) and complex ecological interactions (inadvertent
consumption by larger animals) may contribute to the coexistence of different insect species feeding upon the same host
plant.
Key words:
frugivory, seed predation, trophic interactions, tropical dry forests.
