Eucalyptus leaves are preferred to cerrado native species but do not constitute a better food resource to stream shredders

Abstract

We investigated food preferences, growth and survival of the caddisfly shredder Phylloicus angustior while exposed to leaves of Eucalyptus camaldulensis and three native tree species (Myrcia guianensis, Miconia chartacea, and Protium brasiliense) of the Brazilian Cerrado. Because of the low quality of native leaves, we hypothesized that E. camaldulensis would be preferred and would promote higher growth and survival of shredders than Cerrado species. Except for P. brasiliense, all leaves were consumed in the food preference experiment and E. camaldulensis was preferred to native species. Shredder preferences were similar in an in situ experiment, and the consumption rates did not differ between the laboratory and field conditions. In the monodietary experiment, shredder daily growth rates were positive (4.76–6.83%) and did not differ among leaves. Survival of larvae that fed on E. camaldulensis and M. chartacea was significantly higher than those that fed on M. guianensis and P. brasiliense. Our results showed that E. camaldulensis can be an attractive food resource for P. angustior in Cerrado streams. However, the lack of differences in growth do not fully support the proposed hypothesis and suggests that E. camaldulensis does not constitute a better food resource than native leaves of worse quality.