EVALUATION OF RELEASE OF Diaeretiella rapae (M´ INTOSH) FOR CONTROLLING THE CRUCIFEROUS APHID, Brevicoryne brassicae L. ON CAULIFLOWER PLANTS AT SHARKIA GOVERNORATE, EGYPT.

Abstract

Rate of parasitism by the aphid parasitoid, Diaeretiella rapae (M´ Intosh) on the cauliflower aphid, Brevicoryne brassicae L. as well the hyperparasitism on D. rapae were recorded, at Kafer Sakr district Sharkia Governorate during the two successive seasons 2010-11 and 2011-12. Total means of parasitism rates of D. rapae were 23.58 and 28.06 % during the two successive seasons, respectively. The parasitoid, D. rapae was parasitized by two hyperparasitism species Pachyneuron sp. and Alloxysta sp .The seasonal means of hyperparasitism percentage were 28.42 and 29.67% during period of study, respectively. The parasitoid density, in relation to that of host density, had influenced on percentage of parasitism. The highest percentage reached was 87.75% at 15 D. rapae female parasitoids per cage and the minimum was 46.1% at three female adult per cage. On the other hand, the average parasitism ratios in green houses were 73.

Effect Host Plants on Parasitism Rate of the Parasitoid Diaeretiella rapae (M'intosh) on the Aphid Brevicoryne brassicae L.,

“…Aphids are considered as one of the most important pests due to their wide range of host plants in Egypt and in many parts of the world (Ibrahim and Afifi, 1994, Saleh, 2012and 2014. B. brassicae aphid (Hemiptera: Aphididae) feeds on all cultivated and wild cruciferous plants.…”