Population Fluctuations of Two Aphids and Their Main Predators in Broad Bean plants in Qalyubiya Governorate

Abstract

Field experiments were carried out at Qaha, Qalyubiya Governorate, throughout 2017-2018 and 2018-2019 seasons to study population fluctuations of Aphis craccivora (Koch) and Aphis fabae Scopoli infesting broad bean plantations, and two associated predators addition, effects of certain weather factors (daily mean temperatures and daily mean R.H.). A. craccivora had two peaks both seasons (1st week of December and 3rd week of January) and (1st week of December and 1st week of January) in the 1st and 2nd seasons respectively. A. faba showed three peaks in 1st season (2nd week of December, last week of December and 1st week of March). while 2 peaks in the second season (1st week of December. and end of December.) Population fluctuations of A. craccivora and A. faba and associated predators were higher in the 1st season than the second season and C. undcimpunctata was dominant than C. carneaea. A simple correlation between A. craccivora and C. undcimpunctata showed a significant positive correlation in both seasons while with C. carneaea was insignificant negative in the 1st season and positive in the 2nd season, and the relationship between A. fabae was negative in both seasons with the two predators. The relationship between A. craccivora and daily mean temperature show negative insignificant relation during the 1st season while was significant in the 2nd season. Also, the simple correlation with A. fabe was insignificant negative in both seasons .as well as A. craccivora and A. fabe showed the insignificant positive value in both seasons with relative humidity.