Title : Influence of leaf litter quality and predation risk on behavioral patterns of Phylloicus sp. (Trichoptera: Calamoceratidae)
Abstract:
Predation is an interaction food that can generate a cascading effect on ecosystem functions and interactions. The non-lethal predation can induce defensive phenotypic responses in relation to exposure of signs of predation, such as changes in behavior, morphology and life history. The bottom-up control can also exert a huge influence on the behavioral patterns invertebrate shredders, especially in its activity fragmentation. Chemical compositions of different debris can influence food preferences and the construction of their cocoons. This study analyzed the individual and interactive effects of predation risk from fish genus Astyanax and quality of detritus in the behavioral patterns of invertebrate shredders gender Phylloicus (Trichoptera). The experimental design consisted of two levels of predation risk (absence and presence) and two levels of quality of leaf detritus (high and low) in three experimental blocks. The quality of the leaf detritus significantly influenced (p <0.05) body movements of Phylloicus sp., and treatments with Inga laurina showed a higher percentage of this behavioral category. Invertebrates exposed to Maprounea guianensis remained longer among the leaf discs. Furthermore, the larvae of Phylloicus sp. subjected to predation (non-lethal) and low quality leaf detritus became less time within the cocoon. Therefore, nutritional quality may influence the behavioral patterns of Phylloicus sp., and low-quality detritus associated with (non-lethal) predation may result in less time spent building their microhabitat, which is important for their survival, leading to a higher risk of predation. This may negatively affect the abundance of these shredders, and thus, the flow of energy and matter in lotic ecosystems.
