Community structure of arboreal caterpillars within and among four tree species of the eastern deciduous forest

Abstract

Abstract. 1. A seasonally replicated experimental design was used to address the question of how differences within and among host tree species affect arboreal caterpillar communities.2. Seasonal variation influenced caterpillar community composition most significantly, and the similarity among caterpillar assemblages did not necessarily follow the pattern of phylogenetic relatedness among host trees.3. Species richness and abundance of caterpillars were higher on oaks and maples than on American beech. Diversity partitioning models revealed that β diversity was only occasionally greater or less than expected by chance alone.4. When β diversity was significant, values tended to be greater than expected by chance among replicate trees within each species and lower than expected by chance among the four tree species.5. Differences among trees appeared important for determining patterns of species presence/absence for rare species and influencing patterns of species dominance within caterpillar assemblages. Differences among tree species had a significant effect on overall lepidopteran community composition and mean species diversity (i.e. α diversity).6. Because β diversity of caterpillars among host trees was lower than expected by chance, host specificity within the Lepidoptera may be less prevalent than thought previously.