Meeting Abstract
Predation stress affects the behaviors and distributions of many organisms, as well as their interactions with one another. Pea aphids (Acyrthosiphon pisum) are known to increase wing morph formation in generations following lethal predator stress to their colony, but behavioral responses to non-lethal stress, such as reduced reproduction and dropping off the plant, have received less attention. Here we seek to better understand pea aphid behaviors following non-lethal predator stress within and across generations. We exposed adult pea aphids to 2 hours of non-lethal predatory stress, induced by a lady beetle (Hippodamia convergens) with immobilized mouthparts. After exposure, A. pisum reproductive behavior was observed every 12 hours for 48 hours, and the number of offspring produced by stressed and control aphids were tracked. We found that within the first 24 hours, the amount of offspring produced by stressed A. pisum was significantly lower than the amount produced by control A. pisum. The amount of offspring produced over the second 24 hour period, however, was similar between both groups. The reproductive output between both groups over the total 48 hour time window showed no significant differences. These results indicate that stressed A. pisum avoid reproducing in an unsafe environment immediately after predation stress, but this stress response only lasts up to 24 hours. In additional ongoing experiments, we will use parasitoid wasps to induce non-lethal stress in A. pisum adults, and then investigate behavioral responses to non-lethal stress across subsequent generations. We expect that the offspring of A. pisum exposed to non-lethal stressors will exhibit more predator avoidance behaviors than control A. pisum. These experiments will contribute to our understanding of how reproductive and antipredator behaviors can be modified across generations of genetically identical organisms.
