Frightened feeding: Assessing the impact of parasitic wasps on aphid feeding using the electrical penetration graph technique

Predator-prey interactions are fundamental relationships within ecological systems. The risk of predation alone can have significant impacts on prey populations. Predation risk can induce various behaviors and responses in prey that can affect prey population size, considered a non-consumptive effect on the prey. Previous research has found that parasitic wasps (Aphidius colemani) exhibit significant non-consumptive effects on aphid populations (Myzus persicae). For this project, we aimed to develop a method to quantify aphid feeding in the presence of a parasitic wasp, thereby enabling us to understand how parasitism risk influences aphid feeding behavior by using the electrical penetration graph technique (EPG). The aphids were wired through a clip cage and then hooked up to the EPG system, and a wasp was added to the cage during the recordings. Then, the wavelength outputs were analyzed and compared to the control cages without wasps. The clip-cage design proved to be successful, producing clear waveforms with minimal interference comparable to those in trials without clip cages. Incorporating the parasitoid complicates traditional analysis approaches in EPG, so the interpretation of the waveform patterns was informed by paired behavioral observation assays. By incorporating natural enemy exposure treatments in combination with the EPG, we can acquire a better understanding of the interactions between parasitic wasps and aphids.