Included in this list are ladybugs, lacewings, assassin bugs, syrphid fly larvae, adult wasps, spiders and chickadees. Of this list, ladybugs consume the largest number of aphids. Parasitic wasps are also very effective in aphid control. The parasitic wasp deposits an egg inside the body of the aphid. The egg hatches into a larva that consumes the aphid, leaving only an empty shell.
Biological control can only be effective if natural enemies are present.
Thus, it is important to attract and protect them. Tansy and marigold plants can be used to attract beneficial insects. Additional ladybugs can be purchased to increase populations. Check with your local garden center representative for ordering and availability. There are several physical control methods to use in controlling aphid populations.