Tired of Fungus Gnats? Meet the Beetle That Lives to End Them.
This is Dalotia coriaria, also known as the rove beetle. It doesn’t just suppress fungus gnats—it hunts them down, flips the soil, and ruins their entire reproductive plan.
It works quietly, overnight, and underground. And it works fast.
Dalotia coriaria (Rove Beetle)
Fast-Acting Soil Predator for Fungus Gnats, Shore Flies, and Thrips Pupae
You won’t see Dalotia often—but you’ll know it’s there. Fewer fungus gnats. Stronger roots. No more mystery stunting in your soil-grown plants.
This beetle is highly mobile, nocturnal, and specialized for top-layer substrate hunting. It thrives in peat, coco, leaf litter, worm castings—basically anything with a little moisture and organic matter.
What It Targets
| Pest | Notes |
|---|---|
| Fungus gnat larvae | Primary target. Lives to destroy them. |
| Shore fly larvae | Added bonus—will clean up moist trouble zones. |
| Thrips pupae (in soil) | Complements foliar predators like Swirskii and Andersoni. |
Note: Dalotia does not hunt adult thrips. Pair with foliar predators for full lifecycle coverage.
How It Lives
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Lifespan: ~3–4 weeks
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Reproduction: Eggs to adults in under 3 weeks
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Activity: Mostly nocturnal, fast, and fully uninterested in sticky traps
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Habitat: Top 1–2 inches of moist soil, mulch, or substrate
This is one of the few biological controls that actually runs down its prey.
How to Use Dalotia
| Use Case | Application Rate |
|---|---|
| Preventative | 1 beetle per sq. ft., every 4–6 weeks |
| Active infestation | 1–5 beetles per sq. ft., depending on severity |
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Apply directly to the substrate—no need to bury or prep
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Distribute across beds, pots, or propagation trays
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Can be combined with nematodes or soil mites—no conflict
Treatment or Prevention?
Both.
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Use it as a treatment when fungus gnats or shore flies are already active.
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Use it as prevention in propagation zones, tents, or high-risk areas.
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Reapply periodically to maintain coverage and reproduction cycles.
Dalotia starts hunting immediately on arrival—and if conditions are right, they’ll reproduce and persist.
Why Choose Dalotia?
| Feature | Advantage |
|---|---|
| Speed | Unlike mites, they cover real ground and chase prey |
| Target-specific | Especially lethal to fungus gnat larvae |
| Reproductive | Builds population over time, unlike nematodes |
| Humidity-flexible | Doesn’t need ultra-humid conditions to work |
| Cooperative | Plays well with mites, nematodes, and other biocontrols |
| Efficient | Active hunters that don’t wait for pests to walk by |
Use Stratiolaelaps for slow, steady coverage. Use Dalotia when you want a hit squad.
Environmental Fit
| Factor | Ideal Range |
|---|---|
| Temperature | 68–85°F |
| Humidity | Flexible; 50–80% preferred |
| Light Sensitivity | Shy during the day, active overnight |
| Substrate Type | Peat, coir, compost, worm castings, etc. |
Grow lights, tents, foggers, or greenhouses—Dalotia adapts. Just don’t let it dry out.
What to Expect
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You probably won’t see them
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You’ll stop seeing fungus gnats
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They’ll reproduce quietly if conditions are good
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Your root systems will thank you
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Your sticky traps will suddenly get boring
Shipping & Storage
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Shipped overnight in a loose carrier mix
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Includes a mix of adults and larvae
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Use within 24–48 hours of arrival
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If needed, store at 50–59°F
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Do not freeze or expose to heat or direct sun
Good to Know
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Compatible with nematodes, predatory mites, and lacewings
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Sensitive to pesticides and soil drenches
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Can fly (but usually won’t unless overcrowded)
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Thrives in high-value crop environments, tents, and propagation zones
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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