author(s)
Mohammed Ahmed Ibrahim Youssif

abstract
The seasonal abundance of coccinellid species and their insect parasitoids on pear trees at El-Khattara district, Sharkia Governorate, Egypt was studied during 2017-2018 seasons. Summarized results show the following: Seven predaceous species belonging to family Coccinellidae viz., Coccinella undecimpunctata L., Coccinella septempunctata L., Coccinella 9-punctata L., Scymnus syriacus Mars, Scymnus interruptus (Goeze), Cydonia vicina isis Cr. and Cydonia vicina nilotica Muls were recorded on pear trees infesting with aphid, Aphis gossypii Glover. The general relative densities of the predators were 31.62, 29.25, 25.84, 5.68, 5.14, 1.63 and 0.84% of the total numbers of predators, respectively. C. undecimpunctata activity showed three and two peaks in the first and second seasons, respectively. The highest total monthly counts of 500 predators, was obtained during March, followed by 406 predators during April in the first season. The highest total monthly numbers of 553 predators was found during April in the second season. Five species of hymenopterous parasitoids belong to three families were emerged from collected coccinellid predators, viz., Telenomus sp., Perilitus coccinellae (Schrank), Tetrastichus coccinellae Kurd., Tetrastichus principiae Domenichini and Tetrastichus sp. The pupal parasitoid, T. coccinellae came in the first rank, represented by 30.23%, followed by T. principiae 22.83%. The fluctuations of total percentages of parasitism indicated four and three peaks in the first and second seasons, consecutively. The mean parasitism percentages of coccinellid predators were 14.91 and 17.26% in the first and second seasons, consecutively. The correlations between the total number of coccinellid predators and parasitism percentages were positive, being highly significant in the both seasons. Temperature and relative humidity influenced coccinellid predators population by 60.71 and 45.09% in the first and second seasons, consecutively. Temperature and relative humidity affected parasitism percentage by 46.77 and 56.69 in the first and second seasons, respectively.