Parasites for Control of Aphids

Aphid parasite: Aphidius colemani

For green peach and melon aphids. Aphidius colemani is a small parasitic wasp that lays its eggs in aphids. The eggs hatch inside and the larvae spin cocoons which swell the aphid’s body. The adult wasp then exits the aphid body, leaving behind a hard brown shell called an aphid mummy. Larval development takes 2 weeks at 21° C. (70° F.). These wasps do not diapause, and in fact are most effective from September -March because their own parasites are not present. Used with Aphidoletes in greenhouse peppers in Canada.
Optimal Environment: 50-76°F. Tolerates cool temp., low light.

Aphid parasites: Aphidius ervi and Aphelinus abdominalis

Tiny parasitic wasps that are unique in their ability to control potato aphids and greenhouse potato aphids.

Predators for Control of Aphids

Aphid Predatory Midge: Aphidoletes aphidimyza

This delicate midge produces orange larvae that feed on aphids. Females lay 100-200 tiny orange eggs near aphid colonies. Each larva kills from 4-65 aphids. The short days of winter can cause diapause (dormancy) – prevent by supplemental lighting (one 60 watt bulb per 30 feet, or 100 watt bulb per 65 feet).
Optimal Environment: 73-77°F, OK to 60°F; 80-90% RH.

Lacewings: Chrysoperla rufilabris

Lacewings are general predators: aphids are the main prey, but they also feed on mealybugs, scales, spider mites, thrips, and small caterpillars. The adult is 1/2-3/4 in. long, green or light brown, and has large clear wings with lacy markings. The larvae are voracious predators known as aphid lions, and look like small, mottled alligators. A single aphid lion will consume 200-300 aphids. Lacewing eggs are light green and elevated on tall slender stalks, but lacewings almost never reproduce in the greenhouse.
Optimal Environment: 60-80°F.

Field-collected Ladybeetles: Hippodamia convergens

Ladybeetles are general predators that prefer aphids, but will also feed on scales, thrips, and small caterpillars. They are expecially attracted by aphids. Adult females lay clusters of orange, bullet shaped eggs on the underside of leaves, but only near heavy aphid infestations. Adults can consume 5000 aphids each during their lifetime. One pint contains approximately 9,000 ladybeetles
Optimal Environment: 61-82°F, OK to 55°F.

Aphid Guard™ Aphid Banker Plants

Barley with bird cherry oat aphids (aphids that attack cereals but do not attack broad leaved plants. Aphid banker plants are used to support a healthy beneficial population. Grow your own investment in beneficials and protect plants season-long.

Optimal temperature: 70 to 75 F.

Can I still spray if I need to?
Yes. If pest populations reach threshold levels, you can choose pesticides that will not harm beneficials. Or you can move the banker plants out of the greenhouse until the pesticide has dissipated.

When should I order?
4 to 6 weeks before you expect aphids. Beneficials reproduce at a much slower rate than their prey. Help them get well established before pests arrive.