Aphidoletes aphidimyza is a beneficial predatory gall midge used for biological aphid control in greenhouses and protected crops. This tiny insect is valued by growers for its ability to find and suppress aphid populations naturally, making it a key component of Integrated Pest Management (IPM) strategies.

Unlike parasitic wasps, Aphidoletes aphidimyza targets aphids through its larvae, which are the active feeders. Adults are mainly involved in reproduction and egg laying.

Here’s What They Look Like at Different Stages of Their Life:

Growers often do not see Aphidoletes aphidimyza adults in the crop as they are nocturnal, so understanding the life stages helps with monitoring and timing:

• Egg: Tiny, elongated, and pale orange eggs are usually laid near aphid colonies and are hard to spot without magnification.
• Larva: The larvae are the primary feeding stage. They are small, orange maggots with black mouthparts and actively feed on aphids.
• Pupa: Mature larvae drop to the moist soil surface and form a cocoon where they pupate. These cocoons are oval and covered in soil particles.
• Adult: Adults are small, delicate flies with slender bodies and patterned wings. They search plants for aphids and lay eggs close to infested areas.

Why Growers Love It:

• Larvae consume aphids, significantly reducing pest populations.
• Adults are efficient at locating aphid colonies, even among many non-infested plants.
• Can be used in combination with other aphid biocontrols like parasitic wasps.
• Offers a chemical-free solution to aphid problems, fitting neatly into IPM approaches.

Timing is critical to achieving success with gall midges. They perform best when introduced after pests reach outbreak levels. This is because the number of eggs laid per female depends on the quantity of honeydew ingested, and the amount of food on the plant that can be consumed by the larvae. Females will deposit five times as many eggs on leaves that have 60+ aphids on them.

Preventive use:

• Do not use for preventative use.

Curative use:

• Effective when a large number of aphid species are present.
• Multiple releases will be required if pest pressure is high or crop is mature and dense.

Environmental Conditions:

• Performs best between 20–30°C, with activity decreasing below 12°C.
• Gall midges are active at night, so maintaining night temperatures above ~12°C helps ensure successful egg laying.
• High relative humidity (>70%) enhances performance.
• Suitable for vegetables, ornamentals, herbs, and indoor plant production.

Note: Monitoring is essential. After 14-21 days from the first release, inspect leaves, flowers, and fruit clusters to determine if additional releases are required. Specifically look for larvae.

Proper release techniques ensure Aphidoletes aphidimyza establish quickly and begin controlling pests effectively:

1. Timing the release: Introduce Aphidend when a hot spot is found in your growing space. Use within 1-2 days after receipt.
2. Placement: Open the bottle and place it on the soil, rockwool slabs, or hang it among plants — do not scatter the contents.
3. Dispersal: Once adults emerge, they will fly out and begin dispersing through the crop.
4. Release rate: Rates typically range from 1–10 midges per m² per release, adjusted based on crop, climate, and aphid pressure.
5. Repeat releases: Weekly or bi-weekly introductions are recommended until aphid populations are under control.

Tips for Selecting Rate:

• For dense crops, high pest pressure or curative use → choose a higher rate and repeat releases, weekly or bi-weekly (every 7-14 days).
• For small hot spots in low‑pressure crops → choose a lower rate, and watch for product establishment.
• Always match release strategy to crop size, foliage density, pest risk, and environment.

Visual checks: After 14-21 days from the first release, inspect leaves, flowers, and fruit clusters to determine if additional releases are required. Specifically look for larvae.

Supplemental releases: If aphid count remains high or increases, consider additional releases or review your IPM plan for gaps (e.g., residual pesticide effects, low humidity zones, new pest introduction).

Record‑keeping: Track release dates, environmental conditions, pest levels and predator observations to refine future programs.

What to Expect After Release:

• First week: Adult females will emerge from the container and begin laying eggs in aphid infestations.
• 2-3 weeks: Aphidoletes aphidimyza larvae will begin showing up in aphid infestations.
• Visual Suppression: After 21 days, with multiple weekly or bi-weekly installments, the aphid population will begin to decrease.

• Ensure conditions meet temperature and humidity recommendations.
• Repeat releases weekly or bi-weekly until aphid suppression is achieved.
• Avoid heavy pesticide use near release areas as chemicals can harm midges.