Effect of the microbial conditioning and temperature increase on the leaf consumption by shredders in Amazonian aquatic systems

We used experimental chambers to evaluate the effect of the temperature increasing and microbial conditioning degree on the survival and leaf consumption of two plant species [ Protium spruceanum (Burseraceae) and Goupia glabra (Celastraceae)] by larvae of the shredder Phylloicus elektoros . We also evaluated the sporulation rate of the conditioned leaf debris. The leaf discs were incubated for 0, 7, and 15 days in a stream. Posteriorly, the treatments were inserted in chambers with temperatures of 23.2 °C and 27.5 °C. The higher sporulation rate was found in leaves of G . glabra , with no difference in sporulation among the microbial conditioning treatments. The larval survival was lower in treatments with leaves of P . spruceanum , and in the warming temperature. The microbial conditioning time did not influence larval survival. The effect of the conditioning time and temperature on the leaf consumption depended on the plant species. The foreseen temperature increases and reduction of the palatability of the leaves due to the climate change may result in negative effects on the leaf consumption and survival of larvae of P . elektoros .