Relationship between plant development, tannin concentration and insects associated with Copaifera langsdorffii (Fabaceae)

Plant development is the main factor that determines the insect-ontogeny interaction, since it leads to variations in resource quality and availability. The aim of this study was to test the hypothesis that plant development and varying tannin concentration leads to changes in species richness, abundance and composition of ants, free-feeding herbivores and galling insects associated with Copaifera langsdorffii (Fabaceae). The plant ontogeny and tannin concentration effects on insects were tested on 60 individuals with height varying from 0.9 to 11.0 m. A positive correlation was observed for tree height and species richness and abundance of ants, free-feeding and galling insects. In contrast, we did not find a significant relation between leaf tannin concentration and plant height, or richness and abundance of the different insect guilds. The assemblage of ants (composition of species) did not change between saplings and adults of C. langsdorffii. However, the assemblage of free-feeding herbivores and galling insects varied between the two development stages studied. The present study reveals an ontogenetic succession pattern for herbivore insects along the C. langsdorffii growth, probably due to both indirect and direct benefits from the host plant architecture and quality. Those plants with more complex architectures should support a wider diversity of insects, since they present higher number of sites for egg laying, housing, feeding and better environmental conditions. This is the first work to investigate the host plant ontogeny effect on insects in Cerrado “Savanna” vegetation. The pattern described, along with other previous studies, suggests a vast occurrence of ontogenetic succession in tropical areas.