Impact of Some Weather Factors on the Population Density of Phenacoccus solenopsis Tinsley and its Natural Enemies

Abstract

The aimed of this investigation was to estimate the seasonal abundance and activity periods of the cotton mealybug, Phenacoccus solenopsis Tinsley and its associated parasitoid on okra plants. The present experiment was conducted at Hihhya distract, Sharkia Governorate during two consecutive seasons 2017 and 2018. Plant samples were taken weekly to calculate the population density of different stages of tested pest and its parasitoid, the effect of some weather factors, the number of generations and the best leaf surface. The present work was found a reverse relation between the populations of the cotton mealybug (CMB) and its associated parasitoids. The population dynamic of CMB was high while the population of its parasitoids was low in the first season. On the other hand, the opposite results were obtained during the second season. The P. solenopsis had two to three generations during the first and second seasons, respectively. There was significantly positive correlation between maximum temperature and the population females of this insect whereas, a significant negative correlation was found with mean of relative humidity during the period of this investigation.The results of this study may help the researchers for designing a comprehensive pest management program and prediction models for the cotton mealybug to restrict their further spread.