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

Abstract

Development of green peach aphid, Myzus persicae (Sulzer), was modeled under high and ßuctuating temperatures to determine what effects an increase in mean summer temperatures of 2.5Ð3.5ЊC would have on green peach aphid populations in Minnesota and North Dakota. Green peach aphid developed faster and had greater fecundity under ßuctuating conditions. The constant tem-perature model failed to predict observed development under ßuctuating temperatures (R 2 ϭ 0.01). Optimal temperature for green peach aphid population growth was 26.7ЊC. The lower and upper developmental thresholds were 6.5 and 37.3ЊC, respectively. Under optimal conditions, intrinsic rate of increase was 0.356, and population doubling time was 1.95 d. At optimal ßuctuating 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 38.5ЊC. It seems that, in midwestern North America, green peach aphid would beneÞt from an increase in mean summer temperature (20ЊC) of 2.5Ð3.5ЊC.