A.M.A. IBRAHIM, S.A. EL-ARNAOUTY AND K.T. AWADALLAH
Biological Control Lab., Fac. Agric., Cairo Univ., Cairo, Egypt

ABSTRACT

The present paper deals with the effect of pruning process on population densities of aphids and mealy-bugs infesting apple trees at the Giza region. The aphid species found were; Myzus persicae (Sulz.), Aphis gossypii (Glov.) and Aphis pomi De Geer, while the mealy- bugs were only represented by Icerya seychelarum species Statistically, the pruning process showed a significant effect, i.e. the counts increased on pruned trees than unpruned.
The secured parasitoids associating with aphids were Diaeretiella rapae Mcintosh, Ephedrus persicae Froggatt, Aphidius matericariae Hal. and Praon volucrea Hal., their counts were calculated with those of aphids. Statistically, pruned showed a significant effect on the counts of parasitoids. For the predators associated with aphids, six groups belonging to the families:
Chrysopidae, Seyrphidae, Coccinellidae, Staphvlinidae, Cecidomyidae and Mantidae were reported. Their counts reached a peak in May and September. The counts of predators in relation to aphids was equivalent in the presence or absence of pruning.

Key Words: Sap-Sucking pests, natural enemies, pruning, apple trees.