Aphid midges
Beginner
Scientific name
Aphidoletes aphidimyza (Cecidomyiidae)
Identification
Eggs:
- Oval,
- Minute (0.1-0.3mm),
- Orange.
Larvae:
- Lifestage most commonly seen in orchards,
- Resemble small (2-3mm) orange maggots,
- Food source affects the colour of larvae, which ranges from bright orange to red,
- Larvae use their strong “jaws” to grasp their prey.
Adult:
- Small files (2-3mm),
- Long, dangling legs and long antennae,
- Seldom observed in the orchard.
Often Confused With
- Syrphid (hoverfly) larvae - Syrphid larvae are much larger in size and are yellow green in colour.
- Apple leaf curling midge larvae – Larvae are indistinguishable, except that apple leaf curling midge are found in groups within the tightly curled margins of leaves and in the absence of prey items.
Interaction With Host
Aphid midge larvae are an important natural enemy of aphids, attacking more than 60 different species. Larvae paralyze aphid by attacking their leg joints, and then sucks them dry, leaving a blackened, collapsed aphid attached to the leaf. Larvae kill more aphids than required to complete their development, particularly at high prey densities.
Period of Activity
In apple orchards, larvae are most common in the field from bloom to late summer and are often found feeding in green apple aphid colonies.
Insects Attacked
Larvae are predators of aphids, mites and other soft bodied insects.
Monitoring and Management
Check for the presence of aphid midges in aphid colonies on terminals during scouting. The presence of aphid midges and other aphid predators delays or prevents the need for insecticide applications for green apple aphids. Research in other areas indicates a ratio of 1 aphid midge larva to 15 aphids provides effective biological control. Aphid midges are sensitive to broad spectrum insecticides. See Publication 360 Fruit Production Recommendations for more information on the toxicity of pesticides to beneficial insects.
Advanced
Scientific Name
Aphidoletes aphidimyza (Cecidomyiidae)
Identification
Eggs: Oval, minute (0.1-0.3mm) and orange.
Larvae: The lifestage most commonly seen in orchards – resemble small (2-3mm) orange maggots. Food source affects the colour of larvae, which ranges from bright orange to red. Larvae use their strong “jaws” to grasp their prey.
Adult: Aphid midge adults are small flies (2-3mm) with long, dangling legs and long antennae. They are seldom observed in the orchard.
Often Confused With
- Syrphid (hoverfly) larvae - Syrphid larvae are much larger in size and are yellow green in colour.
- Apple leaf curling midge larvae – larvae are indistinguishable, except that apple leaf curling midge are found in groups within the tightly curled margins of leaves and in the absence of prey items.
Interaction With Host
A. aphidimyza is found on a variety of crops including cabbage, apples, blueberries and ornamental bushes. Aphid midge larvae are an important natural enemy of aphids, attacking more than 60 different species. Aphid midges overwinter as larvae in cocoons in the soil, pupating in spring. Adults emerge in late spring feeding only on honeydew. After mating females lay eggs near aphid colonies. Eggs hatch and the larvae attack aphids, paralyzing them by attacking their leg joints, and then sucks them dry, leaving a blackened, collapsed aphid attached to the leaf. Larvae kill more aphids than required to complete their development, particularly at high prey densities. Females lay approximately 200 eggs, and a single larva kills up to 80 aphids.
Period of Activity
In apple orchards, larvae are most common in the field from bloom to late summer and are often found feeding in green apple aphid colonies.
Insects attacked
Larvae are predators of aphids, mites and other soft bodied insects.
Monitoring and Management
Check for the presence of aphid midges in aphid colonies on terminals during scouting. The presence of aphid midges and other aphid predators delays or prevents the need for insecticide applications for green apple aphids. Research in other areas indicates a ratio of 1 aphid midge larva to 15 aphids provides effective biological control. Females lay approximately 200 eggs, and a single larva kills up to 80 aphids. Aphid midges are sensitive to broad spectrum insecticides. See Publication 360 Fruit Production Recommendations for more information on the toxicity of pesticides to beneficial insects.
