Given their enormous reproductive potential and the damage that they can do, immediate action may be necessary. Consider the aphid density, the current weather conditions, the presence and abundance of natural enemies, the value of the crop, the stage of the crop being attacked, and the time to harvest before making a decision to apply an insecticide. In California, an economic threshold of 30 aphids per plant is used. A similar threshold would work in Manitoba. Comments Aphids are one of the most difficult insects to manage because of their remarkable reproductive ability.
Populations can increase in size at a phenomenal rate.
Each mature aphids may produce 50 to 100 young. There may be up to 15 generations per year.