Temperature Dependent Development of Sugarcane Aphids Melanaphis Sacchari, (Hemiptera: Aphididae) on Three Different Host Plants with Estimates of the Lower and Upper Threshold for Fecundity

Abstract

Abstract The sugarcane aphid, Melanaphis sacchari (Zehntner) is a serious economic threat to grain sorghum across the U.S. sorghum belt. It can develop on multiple grass hosts but only appears to survive winter temperatures in Texas near the Mexican border, Florida and Louisiana. Because survival and reproduction of aphids is dependent on access to appropriate nutrition and temperatures at which metabolic processes are maintained, we evaluated the growth, reproduction and survival of sugarcane aphids at constant temperatures (5°C,10°C,15°C,20°C,25°C,30°C,35°C) on three known hosts, sorghum, Johnsongrass, and Columbus grass. Longevity, fecundity, number of female nymphs/d, reproductive period in d, and intrinsic rate of increase were measured at 24 h intervals. At temperatures below 10°C and above 30°C, reproduction did not occur on any of the hosts. Longevity was maximal at 15oC and thereafter decreased with increasing temperatures. The intrinsic rate of increase was highest between 15oC and 25°C on all host plants, while maximum fecundity differed by host plant and was greatest on sorghum. For aphids feeding on sorghum, the Weibull and Natural models were used to estimate lower and upper thresholds for development based on daily fecundity. The lower threshold for fecundity was 9oC, while the upper threshold for fecundity was 32oC. These results suggest that sugarcane aphid can use alternate hosts for survival and reproduction, but both low and high temperatures limit its reproductive capacity. Higher temperatures may trigger dispersal, while lower temperatures should limit sugarcane aphid fecundity and survival in most of the US. Keywords Growth; Host Plants; Reproduction; SugarcaneAphid; Temperature Threshold