Least-Toxic Control of Insects

Least toxic control of Aphids

Appearance

Aphids:

• Can be green, black, brown, red, pink, or another colour.
• Are pear-shaped.
• Are slow-moving.
• Range in size from 1/16 to 1/8 of an inch long.
• Have obvious, slender antennae.
• Have two tubes called 'cornicles' near the rear end of the abdomen.
• Some may have transparent wings.

Behaviour & effects

Aphids are drawn to new growth. You'll most likely find colonies of aphids along stems or on the underside of a leaf. Several generations can live at the same time and populations can build up quickly.

Aphids are sucking insects. They draw out great quantities of sap, leaving a plant's leaves and stems distorted.

Some plant sap leaks out as honeydew, which makes the plant sticky. Your sidewalk, cars, and patio furniture may become wet with honeydew. A sooty mould often grows in the honeydew and blackens a plant's stems and leaves. Aphids can also transmit plant diseases.

Aphid damage on high bush cranberry


Source: Phil Nixon, University of Illinois Extension

Controlling aphids naturally

You can control aphids naturally by:

• Washing them off with a steady stream of water.
• Avoiding heavy applications of nitrogen fertilizer which can encourage plant growth.
• Introducing natural predators such as lady bugs and aphis-lions to eat the aphids.

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