Effects of High and Fluctuating Temperatures on Myzus persicae (Hemiptera: Aphididae)

Development of green peach aphid, Myzus persicae (Sulzer), was modeled under high and fluctuating temperatures to determine what effects an increase in mean summer temperatures of 2.5-3.5 °C would have on green peach aphid populations in Minnesota and North Dakota. Green peach aphid developed faster and had greater fecundity under fluctuating conditions. The constant temperature model failed to predict observed development under fluctuating temperatures (R super(2) = 0.01). Optimal temperature for green peach aphid population growth was 26.7°C. The lower and upper developmental thresholds were 6.5 and 37.3°C, respectively. Under optimal conditions, intrinsic rate of increase was 0.356, and population doubling time was 1.95 d. At optimal fluctuating temperature conditions, one female aphid produced 12.2 progeny each week while under the most favorable constant temperature conditions; each female aphid produced only 5.9 progeny. Green peach aphid was able to survive 1 h each day above its calculated lethal death point of 38.5°C. It seems that, in midwestern North America, green peach aphid would benefit from an increase in mean summer temperature (20°C) of 2.5-3.5°C.