Table of contents

    Aphids (Brevicoryne Brassicae L. and Other Species)

    Figure 5. Aphids

    Photo by Roy Ellis

    Figure 6. Aphid Infestation on a Canola Plant

    Photo by Phil Thomas

    Identification and Life Cycle

    Occasionally aphids (Figure 5) become abundant in canola crops. Noticeable numbers usually appear at the tops of plants in late July to early August. The aphids frequently cover the entire top 10 to 15 cm (4 to 6") of plants (Figure 6). In most cases, individual or small groups of plants are infested.


    The damage is rarely significant since the bulk of pod formation has been completed, and the damaged top few small pods contribute little to the overall yield.

    Economic Threshold

    There is no economic threshold for aphids in canola.


    Spraying is not economical. Several beneficial insects, like the ladybird beetle and lacewing feed primarily on aphids. Their populations increase as aphid populations increase, usually in numbers sufficient to control the aphids.