Steinernema feltiae (Easy-Release Powder)
Soil-Applied Biological Pest Control for Fungus Gnats, Thrips, and Root Pests
Sticky traps catch adults—but they don’t touch the source.
Neem and sprays stay on the surface.
The real problem is underground.
Steinernema feltiae is a biological soil treatment designed to eliminate fungus gnat larvae, thrips pupae, root aphids, and other soil-dwelling pests before they can emerge. These microscopic beneficial nematodes actively move through moist soil, locate pest larvae, and eliminate them from the inside—breaking the life cycle at its source.
This is soil-first pest control for problems sprays can’t reach.
What Are Steinernema feltiae Nematodes?
Steinernema feltiae are beneficial predatory nematodes used in integrated pest management (IPM) programs for indoor plants, greenhouses, nurseries, and soil-based growing systems.
Once applied, they:
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Seek out soil-dwelling pest larvae
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Enter the host and release symbiotic bacteria
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Kill the pest within days
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Reproduce underground for continued control
They work invisibly, without residue, odor, or re-entry restrictions.
What This Treats (Soil Stages)
| Pest | Life Stage Targeted |
|---|---|
| Fungus gnats | Larvae in soil |
| Thrips | Pupae in substrate |
| Root aphids | Soil-dwelling forms |
| Fungus beetles, weevils, flea beetles | Larvae and grubs |
| More | Dozens of soil-based pests |
If fungus gnats keep returning, this is how you stop the cycle permanently.
Why Choose Easy-Release Powder?
| Feature | Benefit |
|---|---|
| Fast-acting | Kills larvae within 2–5 days |
| Self-replicating | Continues working underground |
| Cool-weather tolerant | Effective down to 46°F soil temps |
| Easy mixing | Dissolves quickly for even application |
| Broad compatibility | Safe with beneficial insects and mites |
This product pairs especially well with predatory mites and predatory insects for complete, full-lifecycle pest suppression.
When to Use This Treatment
Use Steinernema feltiae if:
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Fungus gnats persist despite traps
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Thrips return after foliar treatments
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You suspect root-level pest pressure
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You want chemical-free pest control
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You are building a biological control system
This is ideal for houseplants, rare plants, cabinets, greenhouses, grow rooms, and soil-based containers.
How to Apply
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Pre-water soil so it is evenly moist
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Mix powder into non-chlorinated water (59–69°F)
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Apply using watering can, sprayer, or irrigation
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Lightly water again to move nematodes into root zones
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Keep soil lightly damp for 10–14 days
Avoid dry soil, full sun, or extreme temperatures during application.
How Much to Use
| Use Case | Application Rate |
|---|---|
| Preventative or light pressure | 5 million / 300 sq ft |
| Moderate to heavy infestation | 5 million / 50 sq ft |
| Reapplication | Every 2–4 weeks as needed |
Repeat weekly during heavy fungus gnat pressure or ideal breeding conditions (warm, humid, organic-rich soil).
Best Application Conditions
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Soil temperature: 46–86°F
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Moisture: Damp, not saturated
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Light: Early morning, evening, or cloudy days
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pH: Neutral to slightly acidic
Pro Tips for Maximum Control
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Do not overwater—movement requires oxygen
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Avoid insecticides before or after application
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Reapply to disrupt overlapping pest generations
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Combine with predatory mites (Swirskii, Persimilis) or predatory insects (Orius) for above- and below-ground coverage
This is how professional IPM programs are built.
Safe for Everything That Isn’t a Pest
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Non-toxic
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No residue
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No re-entry interval
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Safe for plants, people, pets, pollinators, and beneficial insects
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Compatible with organic and regenerative growing systems
Shipping & Storage
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Ships with live delivery guarantee
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Refrigerate at 35–50°F (do not freeze)
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Use within 30 days
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Once mixed with water, apply within 6 hours
FAQ
How does the Live Guarantee work?
We know how important it is for your mites to arrive healthy and ready to work. That’s why we offer a live arrival guarantee—with flexible options depending on when we hear from you:
- Let us know within 24 hours of delivery: We’ll gladly send a free replacement shipment.
- Let us know within 2–3 days of delivery: We can offer store credit to make things right.
- After 3 days from delivery: Because these are living organisms, we’re not able to offer replacements or credit beyond that window. By then, it’s harder to know what went wrong or whether shipping conditions were a factor.
We truly want your mites to succeed—so please open your package as soon as it arrives and check on them. If something doesn’t look right, don’t wait—reach out and we’ll take care of you.
Where are you located?
We have a number of different locations in NJ, Maine and Oregon. While we'd love to have you, we are not currently open to the public.
Can I call you?
We get it. Sometimes it's easier to talk to someone, and on a case by case basis we can try to figure it out. Unfortunately though, we're really not able to take calls—FGMN is a small nursery, and we're usually elbows-deep in plants or packing boxes. To make sure nothing gets missed (and everyone gets a timely reply), we keep all communication in writing.
Feel free to message us at info@fgmnnursery.com. We mostly respond quickly, but every once in awhile replies may take a day. Do follow-up if you don't hear in that time. We're human, we miss an email here or there.
Too Many Options?
We get it. Try our mite/insect matchmaking quiz and instantly get matched to the solutions you may need.
Our Live Delivery Guarantee
We stand behind every leaf and every mite. If your plant or predatory insects don’t arrive alive on the first delivery attempt, we’ll make it right.
Here’s what you need to know:
- Email us at info@fgmnnursery.com within 24 hours of delivery
- Include clear photos of the item and the shipping label
- Someone must be available to receive the package—plants and bugs don’t do well sitting in the sun, a mailbox, or the back of a delivery truck
For plants, we offer store credit if something goes wrong.
For predatory mites and beneficial insects, you’ll have the choice of a replacement shipment or store credit.
If you contact us after the 24-hour window, we may still be able to help—just know it’s handled case by case.
We pack with care, insulate when needed, and check the weather before shipping. But once it’s in transit, the fastest way to protect your order is to open it right away.
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