Intensidade de ataque a lagartas artificiais em diferentes formações vegetais do cerrado

Abstract

The structural complexity of the habitat influences the patterns of species diversity and the ecological interactions, such as predation. The aim of this study was to evaluate the intensity of attackon a model of herbivore insect (artificial caterpillars) in the Cerrado vegetation types with different levels of structural complexity (campo sujo, campo cerrado, cerrado sensu stricto and semideciduous forest). The sample units consisted of 40 plots of 10x10m distributed among the four types of vegetation mentioned above. In each plot, 30 artificial caterpillars made of non-toxic clay with similar sizes, shapes and colors were placed on vegetation at about 1m high. The number of artificial caterpillars with attack marks was measured after four days of exposure. The difference in the intensity of attack among the types of vegetation was analyzed using Anova followed by Tukey’s post-hoc test. The mean intensity of attack was significantly higher in the campo sujo (structurally simplest plant formation of the study) than in other types of vegetation (F3,36=7.85, p=0.0003). Due to being more exposed both visually and chemically in the structurally simpler habitat (less richness and density of woody plants) artificial caterpillars can be more easily located and attacked by predators and parasitoids.