Field Studies on the Natural Role of the Predator Chrysoperla carnea (Steph.) Attacking Aphids in a Mixed Orchard Containing Pear and Plum Trees, with Evaluating the Possibility of Using Pheromone Traps against the Peach Fruit Fly, Bactrocera zonata (Saunders).

Abstract

The present study was carried out to record the population density of two aphids' species (the cotton aphid Aphis gossypii on pear trees and the mealy plum aphid Hyalopterus pruni on plum ones) and the green lacewing predator Chrysoperla carnea, which occurred in a mixed orchard containing both trees, during season 2019, in Qalubia Governorate. The obtained data showed that the occurrence of aphids' species on pear and plum trees covered the whole four months of study (March-June, 2019). Aphids' populations were the highest in their numbers, during the two months April and May 2019, on both the two trees species. The results indicated also that, the existence periods of aphids' individuals on both pear and plum trees were the same as those recorded in case of the predator C. carnea. A field experiment was performed by putting pheromone traps on plum trees (during the fruiting season from the second half of May to the first half of July, 2019). Highest total number of the peach fruit fly Bactrocera zonata males was recorded in pheromone traps during the first half of June, 2019 (when using one or two pheromone capsules on the same glued sheets, on the same plum tree). Generally, the lacewing predator C. carnea can be massed reared in the laboratory and released for controlling aphids on pear and plum trees and/or other fruit trees that are subjected to attack by the two aphids' species. Besides, the pheromone traps can be used against the peach fruit fly B. zonata on plum trees and/or fruit trees that suffer from pest attack. The uses of either C. carnea and/or pheromone traps can be applied with other available safe control methods, in the frame of Integrated Pest Management (I.P.M.) programs, for protecting man heath and the surrounding environment from pollution.