Preventative Control for Thrips & Broad Mites
The Heavy Hitter for Warm, Humid Grow Rooms.
If you’ve fought off thrips or broad mites before, you already know the drill: they are microscopic, sneaky, and nearly impossible to spot until the damage is done.
Amblyseius swirskii is the polyphagous (generalist) predator you want in your corner to make sure it doesn't get that far again. These slow-release sachets contain a breeding colony of mites that patrol your plants for up to 4 weeks, consuming the microscopic eggs and larvae of pests before they can grow into a visible problem.
How It Works: The voracious Generalist
A. swirskii is an aggressive predator that thrives in warm, humid environments. Unlike specialists that only eat one thing, swirskii has a wide appetite.
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Slow Release: Each sachet acts as a mini-nursery, releasing eggs, juveniles, and adults continuously over 2–4 weeks.
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Preventative Patrol: As they exit the sachet, they disperse across the canopy, hunting for soft-bodied prey in the earliest stages of development.
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Pollen Feeder: In the absence of pests, swirskii can survive on pollen or supplemental food (like our Good Bug Diet), making them excellent for pre-emptive release.
Targeted Pests
Amblyseius swirskii is famous for its ability to control multiple pest families simultaneously.
| Target Pest | Scientific Name | Targeted Stages |
| Thrips | Frankliniella spp. | Eggs and Larvae (L1/L2) |
| Whiteflies | Bemisia, Trialeurodes | Eggs and Larvae |
| Broad Mites | Polyphagotarsonemus latus | All life stages |
| Russet Mites | Aculops lycopersici | All life stages |
Ideal Conditions
Swirskii are tropical predators. They perform best when your environment mimics their natural habitat.
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Temperature: 77–85°F is ideal. (Minimum 68°F for activity).
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Humidity: 60–80% Relative Humidity (RH) is optimal.
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Best For: Greenhouses, grow tents, indoor cabinets, and tropical plant collections.
Note: If your space runs cool (below 68°F) or very dry, consider using Amblyseius cucumeris or Amblyseius californicus instead.
Application Instructions
Hang High, Keep Dry.
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Preventative Rate: 1 sachet per plant (for large plants) or 1 sachet every 2–3 feet (for dense canopies).
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Placement: Hang the sachet on a branch or stem, just above the soil line but shaded by leaves if possible.
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Maintenance: Do not open the sachets; mites exit through a pre-engineered vent.
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Frequency: Replace every 2–4 weeks depending on temperature (hotter temps = faster release).
Pro Tips for Success
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Feed Them: If you are releasing into a "clean" room with no pests, dusting with a supplemental food source (like pollen or Good Bug Diet) helps establish the population.
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No Sprays: Avoid using oils or foliar sprays while sachets are active. Even organic sprays can clog the sachet vents or harm the predators.
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Layering Strategy: If you have an active infestation, use Swirskii in bottles for an immediate knockdown, then hang sachets to maintain long-term control.
Frequently Asked Questions
Can I see the mites working?
Likely not. A. swirskii are tiny (less than 1mm), fast-moving, and often hide on the undersides of leaves. Trust the process—if you aren't seeing new pest damage, they are doing their job.
Are they safe for pets?
Yes. Amblyseius swirskii is 100% non-toxic and safe for humans, pets, and pollinators.
What if my humidity drops?
Brief drops in humidity are fine, but sustained dryness (below 50% RH) will dry out the sachet media and reduce the lifespan of the colony.
Shipping & Storage
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Freshness: Ships via 2-Day Shipping with a live arrival guarantee.
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Usage: Hang immediately upon arrival for best results.
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Storage: If necessary, store at 50–55°F for up to 48 hours.
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Warning: Do not store in a standard refrigerator or freezer (the air is too dry).
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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