The impact of phenology on the interaction between a predaceous aquatic insect and larval amphibians in seasonal ponds

Phenology has an important effect on the life strategies of species that live in temporary waters. Predaceous aquatic insects are key components of communities associated with seasonal ponds. Since the life cycles of these predators and their prey are unusual in that they occur at different moments of the pond hydroperiod, differences in temporal overlap could change the strength of their interactions. This study analyzed the phenology of the giant water bug Belostoma bifoveolatum and its prey. Breeding phenology, nymph population, and prey phenology were studied extensively in three wetlands during the spring season. Experimental trials were carried out to evaluate prey consumption and prey preference. The results showed a strong overlap in phenology between the water bug and the Pleurodema thaul frog. The timing of tadpole and water bug nymph hatching could ensure high survival levels of the early immature stages of this insect. As giant water bugs develop, their prey selectivity experiences a shift—older nymphs and adults having a higher impact on tadpoles. The fluctuating climate of the Patagonian region probably influences the phenology of predator–prey assemblages in seasonal communities, and may have the potential to drive feeding performance and the strength of interspecific interactions.