Agriculture: Alfalfa Pest Management Guidelines

Natural Enemies of Aphids

Aphids in alfalfa have many natural enemies. Use the photos below to identify predators and natural enemies of aphids. Names link to more information on identification and biology.

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Natural enemies of aphids

Predaceous larva of convergent lady beetle
Convergent lady beetle
Identification tip: Larvae are elongate with long legs and resemble tiny alligators.

Adult convergent ladybeetle
Convergent lady beetle (adult)
Identification tip: Adults are mostly orange with black spots and converging white marks on the thorax. Some individuals have fewer spots, and some, no spots.

Sevenspotted lady beetle larva eating an aphid
Sevenspotted lady beetle (larva)
Identification tip: Larvae are elongate, grayish, yellow- spotted, and alligator shaped.

Adult sevenspotted ladybeetle
Sevenspotted lady beetle (adult)
Identification tip: Adults have a black thorax with white along the front margin. Seven black spots are on the red or orangish wing covers, which may have 2 white areas near the front.

Aphidius parasite parasitizes pea aphid.
Parasitic wasp
Identification tip: Parasitic wasps such as this Aphidius sp. lay their eggs in aphids.

Mummified skin of pea aphid showing parasite exit hole
Parasitic wasp (aphid mummy)
Identification tip: The cuticle of aphids killed by parasitic wasps turn bronze (or black) and crusty and are called mummies. The exit hole is evidence that the parasitic wasp has emerged.

Predaceous adult bigeyed bug
Bigeyed bug
Identification tip: Adults and nymphs are oval, somewhat flattened, about 1/4 of an inch long, with a wide head and prominent bulging eyes.

Damsel bugs
Damsel bugs
Identification tip: Adults are slender insects that are mostly yellowish, gray, or dull brown, measuring about 2/5 of an inch long, and have elongated heads and long antennae.

Minute pirate bug attacking an aphid
Minute pirate bugs
Identification tip: Adults are small, 1/12 to 1/5 of an inch long, oval, black or purplish with white markings, and have a triangular head.

Syrphid fly larvae
Syrphid fly
Identification tip: Larvae are legless, maggot shaped, and opaque with tapered heads.

Fungal killed aphid
Fungal diseases
Identification tip: Entomopthora fungi first turn aphids pink and brown, later causing them to shrivel up and die.

Text Updated: 11/06