Aphid Midge

The aphid midge, Aphidoletes aphidimyza, is a small fly in the gall midge family (Cecidomyiidae) best known for its predatory larvae. While the adults are inconspicuous, delicate midges that feed on honeydew, the tiny orange larvae are specialist aphid predators.

This midge is widespread across temperate regions and is commonly used in biological control, especially in greenhouses, where it is released to keep aphid populations in check. A single larva can consume many aphids during its development, making it an efficient natural enemy.

Adults are active mainly at night, resting on foliage during the day. Females are drawn to the honeydew and scent of aphid colonies, where they lay their eggs so the emerging larvae have an immediate food supply.

Look for these features:

• Tiny, delicate fly about 2-3 mm long with long legs and antennae
• Slender grayish to brownish body
• Small orange larvae found among aphid colonies
• Larvae legless, tapered, and maggot-like
• Often seen in gardens and greenhouses where aphids are present

Lookalikes include other small midges and gnats, but the association of orange larvae with aphid colonies is characteristic.

The aphid midge is found across temperate regions of the Northern Hemisphere and is widely used in protected cultivation worldwide. It occurs in gardens, fields, orchards, and greenhouses wherever aphids are abundant. Adults are active during warmer months and favor humid, sheltered conditions.

Adult aphid midges feed on aphid honeydew and are active at night. The predatory larvae attack aphids, gripping and feeding on them, and can kill more aphids than they consume. By preying heavily on aphids, the midge is an important natural regulator of these sap-sucking pests and a valued biological control agent.

The aphid midge undergoes complete metamorphosis. Females lay tiny orange eggs among aphid colonies. The emerging orange larvae feed voraciously on aphids for one to two weeks, then drop to the soil to pupate in a small cocoon. Adults emerge to mate and repeat the cycle, producing several generations per season, with pupae overwintering in the soil in cooler climates.