Neoseiulus californicus
10% off your first 4 orders, then 15% off every order after.
Heads up—this is just an estimate. We only ship when the bugs are happy and ready to travel (Mon–Thurs). If a colony needs a beat to peak, or we're propagating a fresh batch, your order might hold up to a week. Treatment bottles jump the line when you've got an active infestation.
Sizing guide
How our sizes work
Sizes are set by how many plants you are treating — not by how much material is in the container.
Every size on every product page names its own coverage right there in the dropdown, so you never have to come here to find a number. Medium — Up to 25 Plants (2,500 Mites) tells you the tier and the count in one line. This page is for the part the dropdown cannot tell you: how to pick between two of them.
These are rough middles. The ladder runs smallest to largest within each product, so a Medium of one species covers more ground than a Medium of another — a nematode drench and a beetle release are not the same job. The count on the size you are looking at is always the real answer.
Pest pressure moves you up the ladder
Plant count is only half the sum. The other half is how much pest is already there. A closed tent holding fifteen plants with thrips on every growing tip needs a larger release than a bright room holding forty plants with a few gnats — the population you are outnumbering is bigger, and the enclosed space lets it rebound faster.
Coverage figures assume a typical active infestation. Adjust from there:
Under heavy pressure, two releases beat one large one. Take the larger size and plan a second release 7–14 days later, which catches the eggs that had not yet hatched the first time.
A few things work differently
A few products read in square feet rather than plants, because that is how they are applied — the outdoor and area-scale releases. Those are Sc and Hb nematodes, and the aphid specialists Ervi, Matricariae, and Aphidoletes. Same ladder, different unit.
Sf nematodes and Triple Blend size by plants and pots, like everything else. They are soil drenches for potted plants, so count your pots rather than your floor.
Slow-release sachets have no size. They are sold by the sachet, and you place one per plant or one per few plants depending on pressure. Sachets are a prevention tool — they hold a population in place before a problem starts. If something is already established, a bottle is the correct answer.
Sizing up is cheaper than sizing twice. Predators need enough prey to establish and enough of themselves to find it. Underdosing is the most common reason a release underperforms, and it usually costs more in the end than the larger size would have. When you are between two sizes, take the larger one.
Still not sure? Tell us what you are growing and what you are seeing, and we will size it for you.
Neoseiulus californicus
At A Glance
Neoseiulus californicus is a hardy, aggressive predatory mite specifically adapted for hot, dry environments. While many beneficials require high humidity to survive, Californicus is the "survivalist" of the mite world. It is a specialized hunter of Spider Mites, but it is also a patient generalist that can stay on your plants for weeks without a primary food source.
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Scientific Name: Neoseiulus californicus
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Primary Target: Two-Spotted Spider Mites.
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Secondary Targets: Broad Mites, Russet Mites, and Cyclamen Mites.
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Key Advantage: Exceptional tolerance for low humidity and high temperatures. It is the best choice for summer greenhouses and indoor grow tents with intense lighting.
Target Pests
Environmental Needs
Selection Guide
How to Use
How They're Shipped
Deploy day, and the weeks after.
How to deploy your order, and how to read the results over the next few weeks.
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01
Open the box right away
Bring the package indoors as soon as it arrives. Don't leave it on a hot porch, in a cold mailbox, or in direct sun. If you can't deploy immediately, set the bottle somewhere room-temperature (60–75°F) and out of direct light — it'll keep for a day or two.
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02
Let the bottle rest 15 minutes
Mites huddle in transit for warmth. Set the bottle somewhere room-temperature for fifteen minutes before you open it. This lets them spread back through the carrier and warm up before deployment.
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03
You probably won't see them
Predatory mites are smaller than a grain of salt. Most people can't spot them with the naked eye, and phone cameras can't focus close enough to catch them. That's expected! What you can check: the carrier material should look dry and uniform, the bottle should be intact, and there shouldn't be visible mold. A warm box is normal — don't read anything into it.
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04
Deploy the same day
Apply in the evening or on a cloudy day to avoid UV exposure. For pests on the plant — spider mites, thrips, broad mites — sprinkle the carrier material directly onto leaves and stems where damage is visible. For soil-dwelling pests like fungus gnats, sprinkle onto the top inch of soil and lightly water afterward to help the mites settle into the medium. Either way, spread across plants instead of piling in one spot. See the product description for species-specific dosing.
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05
Watch your plants over 1–2 weeks
The real "are they working" check isn't visual. It's whether your pest population drops. Bottled treatments typically show measurable reduction in spider mites, thrips, or other targets within one to two weeks. If pest pressure isn't easing by then, that's when to bring in our bug pros.
Something not quite right?
Reach out to our entomologist by filing a report within 72 hours of delivery, with your order number and a photo. Candidly, without a photo the team can't approve a live beneficial claim.
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FAQ
What is your Live Delivery Guarantee?
We guarantee that your beneficial insects and plants arrive healthy and ready to work. They're living things, so we pack for the season and ship expedited to give them the best trip we can.
If something looks wrong when the box opens, take a photo and file a report within 72 hours of delivery, with your order number. Photos matter: candidly, without them the team can't approve a live beneficial claim.
Why should I use a bottle instead of sachets?
Will they get rid of heavy webbing?
How long do they live?
Can I use them with other beneficials?
Is it safe for my pets?
Can I spray my plants?
Help! I'm overwhelmed
Yeah, it's a lot the first time you're using predatory mites. File a report and our bug pros will walk you through it!
I don’t see anything moving in my bottle or sachet. Does that mean they’re dead?
Not at all! In fact, go ahead and deploy them.
Predatory mites are microscopic (often less than 0.5mm) and naturally blend into their carrier medium (bran or vermiculite).
- For Bottles: The mites often huddle in the center of the bottle for insulation during transit.
- For Sachets: These are "slow-release" nurseries. The mites stay tucked deep inside the breeding media and emerge one by one over 2–4 weeks. Seeing an "empty-looking" sachet or bottle is not proof of a loss; it is simply how they are packaged for maximum survival.
I have an established fuscia garden that until this yearIhave been able to manage the mites by removing the damageand adjacent nodes but I don't know if it'sthe warmer weather/climatechange but had an explosion of mites this year including plants not previously impacted. I am on my third round of dosing ànd not sure ifIam seeing much improvement yet, but it's worth trying to keep up with the mites cause the incecticides are so darn toxic.
They have really good customer service and they will attempt to replace your order for you however if you live far from New Jersey I wouldn't suggest trying this it seemed both times all my bugs were Dead on Arrival I essentially paid $80 for a tube of sawdust
Hi Joel,
I'm sure not seeing the mites has been very distressing. Rest assured, it's not unusual nor a sign that they're dead. Most people cannot see the mites.
It sounds like you're working with our customer service team, and I trust they'll be able to help you figure out what might be going on. Or... you may just be in that dreaded phase where you have to wait for them to do their thing. That period of time is absolutely the worst, but the results at the end always make it worth it.
Once again, I'm deeply sorry this has been anxiety-inducing.
Took a couple of weeks but my plants are looking healthy again. Thanks for the advice about which predator to get. Already recommended to a friend!
Hi Stephanie! We're so glad to hear your plants are thriving again and that our advice helped. Thanks for recommending us! We appreciate you.
I was having issues with my Hoya collection not producing any new growth for months. I finally purchased a microscope and found 10 plants covered in spider mites. Last year I dealt with aphids chemically and did not want to repeat that nightmare so I decided to try beneficials. FGMN has been incredible with their customer service. They answered all of my questions, studied my scope photos, guided me through the process and honestly, treated me like a friend in crisis when my frustration nearly got the best of me.
Beneficials have always arrived active and ready to do battle, and I'm happy to report I'm finally seeing new growth on all of my Hoya.
A PSA for those who've not used beneficials before: it takes time and a good deal of patience when working with them. The best thing you can do is just apply and then leave them to do their business. It took weeks before I saw any improvement, but it was better than dealing with chemicals and spraying each plant from top to bottom over and over again; I'm done with that. This is the way to go for me from now on, and this is the only company I'll use.
I can’t write a good review. I can’t write a bad review. I was battling spider mites and I purchased some predatory mites to fight them. However, maybe I bought too little and it was too late. I seemed to still be inundated with The spider mites. Definitely will have to try a biological again in the future as it seems like the better alternative to poison.
This nursery is invaluable to my collection! Their commitment to keeping it bug free goes just as deep as mine does! I have over 200 plants that they are helping me combat the inevitability of pests with, and their guidance/ passion for the work has been an absolute lifesaver! The one-on-one help from customers support, and the encouraging words have really helped me not just knock the pests out, but keep my spirits up! I will be continuing to use them for sure!
This is what they recommended for a spider mite problem, and it’s been over a week with no improvement in the spider mite situation. I have two tomato plants that are hanging on by a thread. For $75 I am very disappointed
Thank you for the feedback — I’m sorry the results haven’t matched what you were hoping for, and I understand the frustration when plants you care about are struggling.
A week is typically too early to judge predatory mite results. Californicus needs 2–3 weeks to visibly bring down a spider mite population, and the heavier the infestation, the longer it takes. If your tomatoes were already badly damaged at release, the mites may also not have had enough healthy tissue to establish on — which is a separate problem from whether they’re working.
I’d really like to take a closer look. Please email us at info@fgmnnursery.com with a few photos of the plants and the leaves (top and underside), and we’ll figure out whether the population needs reinforcement or whether something else is going on.
Great! Solved my spider mites problem quickly
Thank goodness for a type of mite that will work in the hot, DRY Colorado heat! My little mites have been hard at work and I couldn't be happier! Product came fast and well packed. They were coming out the second I opened everything!
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