The insecticides used on canola, mustard and rapeseed can be applied as a seed treatment, granules applied with the canola seeds, or postemergence foliar sprays. Coating seeds with an insecticide in combination with one or more fungicides prior to planting is a common practice. With the seed treatments currently available, canola seedlings are protected from flea beetles as soon as the plants emerge. The seed treatments currently available for control of nea beetles in canola come with the insecticide at either a lower or high rate. The high rate is more expensive than the lower rate, but has an extended period of protection from flea beetles relative to the lower rate.
Research is currently underway on additional seed treatments for flea beetle control in canola.
Refer to Table 1 for the currently registered seed treatments. Counter 5G is extremely effective against flea beetles when used in conjunction with an insecticide seed treatment, especially on early seeded crops. Granular insecticides are taken in by the seedling's roots and translocated to the cotyledons and leaves. Flea beetles receive a lethal dose of insecticide as they feed on the plant. The movement of the insecticide from the in-furrow granules to the cotyledons may take two or three days, during which time the seedlings may be unprotected if an insecticide seed treatment is not used in conjunction with Counter 5G. Maximum protection begins to occur about five to six days after emergence and is available for up to 28 days after emergence.