Fungus Gnat Predators (Hypoaspis Miles) - Biological Control for Soil Pests
Best for: growers dealing with fungus gnats, springtails, thrips pupae or root mealybug in the growing medium who want a biological fix instead of a chemical drench.
Our thoughts
These are alive, so treat them like a perishable, not a bag of granules. Sprinkle them across the surface of the medium as soon as they arrive and they'll get to work on the larvae doing the actual damage, not just the adult flies you can see. A genuinely useful biological option if you'd rather not reach for a chemical drench near your root zone.
Hypoaspis miles, also sold under the name Stratiolaelaps scimitus, is a soil-dwelling predatory mite that lives in the top layer of growing medium and hunts fungus gnat (sciarid fly) larvae, along with other soil-dwelling pests including springtails, thrips pupae and root mealybug. This tube contains 10,000 live mites in a bran and vermiculite carrier, ready to sprinkle across the surface of your medium.
Unlike a spray or drench aimed at adult gnats, these mites work continuously in the medium itself, patrolling the top layer and feeding on pest larvae and eggs before they mature and become a visible adult population.
How it compares
Fungus gnat control generally falls into three camps: traps, nematodes, and predatory mites, each targeting a different life stage.
- Vs yellow sticky traps: traps catch adult gnats but do nothing about the larvae living in the medium, which is where the actual root damage happens
- Vs Steinernema feltiae nematodes (also sold by Growers House): both target gnat larvae in the medium, nematodes are watered in and prefer consistently damp conditions, Hypoaspis miles patrol the surface continuously and tolerate a wider moisture range
- Vs a chemical soil drench: a biological option with no chemical residue in the root zone and no risk of pests building resistance over repeated use
Many growers combine sticky traps for visible adults with a soil-dwelling predator like this for the larvae, since the two approaches target different life stages rather than competing with each other.
Usage guidance
These are a living product, so handling and timing matter for how well they establish.
Application
Sprinkle the mites and their carrier evenly across the surface of the growing medium as soon as possible after they arrive, covering the areas nearest the stem where gnat larvae concentrate.
Environment
Keep the surface of the medium lightly moist rather than bone dry or waterlogged, Hypoaspis miles establish best in that middle ground.
Maintaining the population
Avoid broad-spectrum pesticides on the same medium, as these will kill the predatory mites along with the target pest and undo the treatment.
Technical specifications
- Species: Hypoaspis miles (Stratiolaelaps scimitus)
- Quantity: 10,000 mites per tube
- Carrier: bran and vermiculite mix
- Targets: fungus gnat larvae, springtails, thrips pupae, root mealybug
- Habitat: top layer of growing medium
- Supplier: Bioline
- Handling: live biological control, apply promptly on arrival
Who this is for
- Growers with an active or recurring fungus gnat problem
- Anyone wanting to avoid chemical drenches near the root zone
- Growers dealing with springtails, thrips pupae or root mealybug in the medium
- IPM-focused setups already using other biological controls
Best suited to soil, coco or other media-based grows rather than pure hydroponic systems with no substrate for the mites to live in.
Our take
It's a genuinely useful biological tool for a problem that's hard to shift with traps alone. Because it targets the larvae rather than the adults, it deals with the source of the infestation rather than just the visible symptom.
One we sell a lot of to growers who've tried sticky traps first and are still seeing gnats. Worth applying as soon as it arrives.
