الفهرس 
2. Experimental site and samplingOnly 14 pages are availabe for public view
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Abstract
Canola is the third source of edible oils worldwide, after soybean and palm. Egypt suffers from a severe shortage in edible oil supplies. Unfortunately, this important crop is attacked by several insect pests; mainly aphid, scarabids, thrips and leafminer. The high density of these pests occurred by March and April in most cases. These pests were found associated with several parasitoids and predators. The parasitoid, Diaeretiella rapae was obtained from larvae of Brevicoryne brassicae, and the parasitoid, chrysocaris sp was obtained from larvae of Liriomyza brassicae. Percentage of parasitisms were 3.00-3.73% for the first parasitoid, and 4.76-20.62% for the second one. Most important surveyed predators were coccinellids, hoverflies, Aphidoletes aphidimyza and chrysoperla carnea. The most dominant coccinellids were Hippodamia convergens and Coccinella undecimpunctata. However, the most occurring predator was the staphylinid, Philonthus sp. Five canola varieties were evaluated to the infestation by Brevicoryne brassicae; Midas variety was the most susceptible, while Mogul was the most resistant. As for the infestation by Tropinota squalida, Tower variety was the most susceptible, while Savlots Silone was resistant. from the results of the current investigation, it could be concluded that the aphid, Brevicoryne brassicae and the furry rose beetle, Tropinota squalida are the major insect pests, but fortunately canola fields have several parasitoids and predators that can regulate the densities of such insect pests.