Predicting Field Generations of The Green Peach Aphid, Myzus persicae (Sulzer) and Its Predator, Green Lace-Wing, Chrysoperla carnea (Stephens) by Using Heat Units Accumulation and Evaluation of Some Insecticides against Their Populations

Abstract

Applying a precise forecasting method is necessary to achieve acceptable results in integrated pest management programs. The objectives of this work were to predict the occurrence of population of Myzus persicae (Hemiptera: Aphididae) and Chrysoperla carnea (Neuroptera: Chrysopidae), determine the influence of temperature and relative humidity on their population densities and also to study the effect of five insecticides on the population of these insect species in potato plants under field conditions at Nobaria district, El-Beheira Governorate, Egypt. The populations of M. persicae and C. carnea were monitored on potato plants from February to May of 2015 and 2016 seasons. The population peaks of these insects were predicted using a degree-day model (accumulated thermal units). The obtained results revealed that the green peach aphid has nine field generations while the green lace-wing has two field generations. The general average of deviations between the expected peaks compared to the observed peaks were-1.333 and-1 days in case of M. persicae, while these averages were +3 and-1 days in case of green lace-wing in 2015 and 2016 seasons, respectively. The effect of the meteorological factors such as temperature and relative humidity on population of these insect were studied. The correlation results revealed that the incidence of M. persicae and C. carnea were significantly and positively correlated in descending order with minimum, mean, and maximum temperature degree, respectively. The efficiency of acetamiprid, thiamethoxam, pymetrozine, chlorantraniliprole and pirimicarb on M. persicae and C. carnea populations was determined. These insecticides could be arranged in ascending order as: acetamiprid > thiamethoxam > chlorantraniliprole > pymetrozine > pirimicarb for controlling the green peach aphid. While regarding their harmful effect on the C. carnea population their order became chlorantraniliprole > pirimicarb > thiamethoxam > acetamiprid > pymetrozine. These results were repeated in both seasons of study, 2015 and 2016.