Effect of Climate Change on Longevity and Reproduction of<i>Sipha flava</i>(Hemiptera: Aphididae)

Abstract

This study examined effects of elevated CO2 alone and in combination with elevated temperature on plant-aphid interactions. CO2 levels in which the host plants were grown affected the durations of some nymphal stadia, but not the survivorship within each instar or of all nymphal instarS. Sipha flava (Forbes) (Hemiptera: Aphididae) adults kept under a constant high CO2 environment (500 ppm) and fed on plants grown under fluctuating CO2 levels (avg. 440 ppm) in a greenhouse had significantly greater longevity and greater reproduction than aphids fed on plants grown either under a constant high CO2 level (500 ppm) or under fluctuating CO2 levels (avg. 368 ppm). Nevertheless, no significant differences were observed in these biological parameters of S. flava that were kept individually in a greenhouse, regardless of the CO2 and temperatures under which the plants used to feed them were grown. However, populations of aphids kept and fed on plants grown in the greenhouse produced significantly more nymphs and adults than did those fed plants grown in a climate-controlled chamber under a constant high CO2 level (500 ppm). The combination of elevated CO2 and high temperature significantly decreased the duration of nymphal stadia, the longevity and reproductive success of S. flava but not nymphal survival. Adults produced fewer nymphs in an environment with elevated CO2 and high temperature than an environment with elevated CO2 and lower fluctuating temperatures. Based on these results, we concluded that S. flava populations will significantly decrease under future climatic conditions when both the concentration of atmospheric CO2 and temperature are projected to increase.