M.O. KOLAIB
Faculty of Agric., Menoufia University , Shebin el-Kom, Egypt .

ABSTRACT

Rate of parasitism by Diaeretiellarapae (MTntosh), on the cabbage aphid, Brevicoryne brassicae (L.), as well as rate of hyperparasitism on D.rapae were recorded through September, 1989 till August, 1990 at Shebin El-Kom district, Egypt . Results revealed that D.rapae occurred during all months with highest activity during November, December, and January as rates of parasitism were 93.9, 96.4, and 83.9%, respectively.The parasitoid, D.rapae was parasitized by two hyperparasitoids, i.e. Pachyneuron aphidis Bouche, first record in Egypt , and Alloxysra sp. P. aphidis was found during all months except August and September. Its maximum activity was observed during January, February, and March as the rates of hyperparasitism reached 74.33, 87.07, and 83. 12%, respectively. Rates of hyperparasitism by Alloxysta sp. did not exceed 10%. The total hyperparasitism by the two species reached 91% in February.

Key Words: Cabbage, Aphids, Parasitoids, Hyperparasitoids , Egypt .