Aphids are very small insects that suck plant fluids and in large numbers cause leaf and flower damage. Aphids are most active during the spring and fall when plant growth rates are high.

Prevention/Management

• Check plants twice a week for aphids during periods of rapid plant growth. Look on the underside of leaves.
• Control ants, they protect and encourage aphids.
• Check transplants for infestations.
• Avoid high levels of nitrogen fertilizer.
• Summer heat reduces populations.

Controls

• More toxic: broad spectrum insecticides (Malathion, diazinon), systemics.
• Less toxic:

- pyrethrins

- use beneficial insects: parasitic wasps, ladybugs, leatherwing beetles, lacewing and syrphid fly larvae

- prune out damaged plant parts

- knock aphids off plants with a water spray

- try insecticidal soap, narrow range oil, or sticky traps