Phytoseiulus persimilis for Spider Mite Control
Persimilis predatory mite · Phytoseiulus persimilis
4.7 · 14 reviewsLive Phytoseiulus persimilis predatory mites, shipped loose in a carrier, 500 to 20,000 mites per bottle depending on size. A specialist that eats two-spotted spider mites at every stage, tipped straight onto the webbing and hot spots. It needs spider mites to eat and does best at 60% humidity or higher, so it's a treatment, not prevention.
- Best for
- Spider mites
- Conditions
- 59–86°F, 60% RH or higher
- Good to know
- They go straight to work. Tip the carrier near the damage and the mites walk out and find the colony on their own. A bottle that looks like plain wood chip is normal. What to expect
When to choose something else
Not for broad mites, russet & rust mites, thrips, anything on a clean plant.
Shipping details
Shipping
| Est. ships | Est. arrives | |
|---|---|---|
| Standard | ||
| Overnight |
Raising a fresh batch for you? Add up to 7 days to both dates.
Estimates. Overnight speeds up the trip, not the packing: its one day on the truck starts once it ships.
- Monday to Thursday only. Nobody spends the weekend in a warehouse.
- Check your address at checkout. Bugs are brilliant at finding aphids and hopeless at finding a new front door.
Ordering with friends? Get group pricing
Everyone picks their own. It ships to you in one box.
Buying for a greenhouse, farm or shop? Ask about wholesale
Right for you?
Your pest, your growing space, how many you need
What it treats, and what else it eats
Treat. A specialist, made for one pest: spider mites.
| Pest | Treats or prevents | Why |
|---|---|---|
| Spider mites | Treats | Main prey. It goes looking for these first. |
Not for broad mites, russet & rust mites, thrips, anything on a clean plant.
How many phytoseiulus persimilis do I need?
Count the plants you want to cover.
Size guide
| Size | In the bottle | Covers |
|---|---|---|
| X-Small | Up to 10 Plants | 500 Mites |
| Small | Up to 20 Plants | 1,000 Mites |
| Medium | Up to 50 Plants | 2,500 Mites |
| Large | Up to 100 Plants | 5,000 Mites |
| X-Large | Up to 200 Plants | 10,000 Mites |
| 2X-Large | Up to 400 Plants | 20,000 Mites |
- Each size is one release. The treatment plan below says when to check again.
- Count the plants you want to cover.
- Heavy pressure, go one size up; light, one size down. A large plant with a dense canopy counts as three or four plants.
Conditions for releasing phytoseiulus persimilis
Phytoseiulus persimilis work best when the growing space stays 59–86°F, 60% RH or higher. These are preferred conditions, not hard limits.
Best temperature59–86°F
Keep it below about 85°F if you can. In extreme heat spider mites reproduce faster than persimilis does, and the race tips the wrong way.
Best humidity60% RH or higher
The one that matters most. The eggs hatch best above 60%. Misting the foliage or running a humidifier nearby does more for this release than anything else you could do.
RefrigerateBest not
Loose mites do best released rather than held. Open the bottle and release it the day it lands.
Releasing
What to do, and what you'll see
What to expect
- They go straight to work. Tip the carrier near the damage and the mites walk out and find the colony on their own. A bottle that looks like plain wood chip is normal.
- Webbing stops first. The webbing stops spreading, then the spider mites thin out over a couple of weeks. Old stippling stays put; leaves don't repair.
- Then they vanish. Once the spider mites are gone, persimilis goes too. That's the job finishing, not failing.
- Clean new growth is the win. Judge it by the newest leaves coming in unmarked, not by the scars on the old ones.
How to release phytoseiulus persimilis
You may need to retreat
Eggs and young pests you can't see yet keep hatching after the first release. A second round catches that next wave.
You're done when you're seeing fewer pests and new growth comes in clean. Still seeing them, or fresh damage on new growth, at the check? That's your cue for another round.
Put it on a schedule and the next bottle arrives on its own, 10% off the first and 15% off every one after. If it turns out you don't need it, pause or cancel anytime from your account.
Reviews
What growers say
What people say
4.7 out of 5, from 14 reviews.
Fantastic! We introduced at dark and they are happily munching away.
It works
Two words, five stars, zero notes. The persimilis crew is framing this one. Thanks, Ashley!
These are some awesome knockdown predators for spider mites!!! Cleared my plants really fast!!!
The package was misdelivered by FedEx, marked as delivered with a photo of my neighbor’s front door 4 days late.
The seller themselves confirmed the mites would be non-viable. Despite clear photo evidence of the wrong door and FedEx closing their ticket, FGMN refused a refund or to help in any way. Their only response was that I should have bought their $1 shipping insurance, something I never even saw as an option at checkout. If it’s only a dollar, I don’t understand why it isn’t just standard.
Worst customer service I’ve ever received from an online retailer. Will never order from them again.
Hi Travis,
Thank you for reaching out. At this time, you have not been refused a refund. Since your order was marked delivered, we do need FedEx to confirm it was not delivered before we reship new Persimilis to you. I realize the last few days must have felt like an eternity, but FedEx does not work weekends, and we're stuck to their timelines. Once they let us know their final decision on your order, we will happily reship the Persimilis. Hang in there! The claims can take weeks, but since you mentioned that FedEx reached out to you, we should be hearing from them in the next few days.
I followed the instructions provided on the website and was impressed by the results. Many of the plants in my greenhouse were infected, and they did not know what was in store for them. One week after the application and the battlefield was barren. New green leafy growth is what I am greeted with now upon entering the greenhouse.
It is assumption because I did not do a microscopic examination.
I've ordered from other companies before but never have I had as much support as I do with FGMN. Predator mites are newish to me and it was a huge help to be as educated as possible since everyone (human and non) has a job to do. My mites arrived in good shape and got right to work.
Got my bugs quickly. Now if she just kill the spider mites on my plants.
Karen,
I am not very tech savvy! While I was on vacation I could not understand your directions about sending you photos of the fgmn box used in shipping, from my phone to email. The box arrived in perfect condition but I ordered and paid for two sachets and received only one. Please send another. I want to let you know I am not happy with the Phytoseiulus Persimilis. I followed the directions and sprinkled water on the foliage and then sprinkled the crumbly material on the plants. Last night when I got home I saw No evidence of any creatures. I have worked for years to get a thick coverage - ground cover of my pachysandra and I am afraid it is all going to die. When I read about your product I had some hope it would help my plants. However, it does not look promising. I would not recommend your product to my friends.
Hi Anne — thank you for the note. On the missing bottle (or sachet?), please reply to your order confirmation email with a photo of what you received and we’ll take it from there. It doesn’t happen often that we miss packing something, but for anybody who reports missed items we require a photo of what was received. It doesn’t need to be anything fancy, but something to prove the missing product. :)
A couple of things that might help: persimilis are tiny, and the juveniles are translucent — they’re nearly impossible to see by eye, even mixed into the carrier you sprinkled. They also need specific conditions to establish: high humidity (60%+), moderate temperatures (70–85°F), and an active two-spotted spider mite population to feed on. Outdoor pachysandra typically doesn’t hold those conditions, and if a different pest or spider mite is behind the decline, persimilis won’t establish regardless.
If you can send close-up photos of the affected leaves (undersides especially), we’re happy to help figure out what’s actually going on.
So far so good! I've seen Less webbing and little red mites indicating that the spider mites are being eaten. Karen, who I have been back and forth with email, has been a treat to deal with! She is incredibly knowledgeable and not afraid to share that knowledge even on a beginner level with me. I have also decided to exclusively start using beneficials instead of sprays thanks to my experience and her help.
All in all this has been above expectations on every department!
Works well
It was fast delivery, I'm pretty sure that it was only 3-4 days after buying thatI received them. They got the job done! will definitely recommend this nursery to my plant friends and family! Also buying again if needed.!
Very active. Making progress, but time will tell for the spider mites.
I ordered some mites later in the day Wednesday afternoon, I wasn't sure 8f it would ship out that week because of the later order. My order was at my front door Thursday before noon, I will absolutely use this company again and recommend to everyone I know needing help with spidermite.
Can I buy these any where walking in
Hi,
Probably not. They have a very limited shelf life and eat only two-spotted spider mites, which makes keeping them in a physical retail environment very challenging. Please let us know if you find anywhere and we'll refer people there who prefer the physical retail experience!
Fantastic! We introduced at dark and they are happily munching away.
It works
Two words, five stars, zero notes. The persimilis crew is framing this one. Thanks, Ashley!
These are some awesome knockdown predators for spider mites!!! Cleared my plants really fast!!!
The package was misdelivered by FedEx, marked as delivered with a photo of my neighbor’s front door 4 days late.
The seller themselves confirmed the mites would be non-viable. Despite clear photo evidence of the wrong door and FedEx closing their ticket, FGMN refused a refund or to help in any way. Their only response was that I should have bought their $1 shipping insurance, something I never even saw as an option at checkout. If it’s only a dollar, I don’t understand why it isn’t just standard.
Worst customer service I’ve ever received from an online retailer. Will never order from them again.
Hi Travis,
Thank you for reaching out. At this time, you have not been refused a refund. Since your order was marked delivered, we do need FedEx to confirm it was not delivered before we reship new Persimilis to you. I realize the last few days must have felt like an eternity, but FedEx does not work weekends, and we're stuck to their timelines. Once they let us know their final decision on your order, we will happily reship the Persimilis. Hang in there! The claims can take weeks, but since you mentioned that FedEx reached out to you, we should be hearing from them in the next few days.
I followed the instructions provided on the website and was impressed by the results. Many of the plants in my greenhouse were infected, and they did not know what was in store for them. One week after the application and the battlefield was barren. New green leafy growth is what I am greeted with now upon entering the greenhouse.
It is assumption because I did not do a microscopic examination.
I've ordered from other companies before but never have I had as much support as I do with FGMN. Predator mites are newish to me and it was a huge help to be as educated as possible since everyone (human and non) has a job to do. My mites arrived in good shape and got right to work.
Got my bugs quickly. Now if she just kill the spider mites on my plants.
Karen,
I am not very tech savvy! While I was on vacation I could not understand your directions about sending you photos of the fgmn box used in shipping, from my phone to email. The box arrived in perfect condition but I ordered and paid for two sachets and received only one. Please send another. I want to let you know I am not happy with the Phytoseiulus Persimilis. I followed the directions and sprinkled water on the foliage and then sprinkled the crumbly material on the plants. Last night when I got home I saw No evidence of any creatures. I have worked for years to get a thick coverage - ground cover of my pachysandra and I am afraid it is all going to die. When I read about your product I had some hope it would help my plants. However, it does not look promising. I would not recommend your product to my friends.
Hi Anne — thank you for the note. On the missing bottle (or sachet?), please reply to your order confirmation email with a photo of what you received and we’ll take it from there. It doesn’t happen often that we miss packing something, but for anybody who reports missed items we require a photo of what was received. It doesn’t need to be anything fancy, but something to prove the missing product. :)
A couple of things that might help: persimilis are tiny, and the juveniles are translucent — they’re nearly impossible to see by eye, even mixed into the carrier you sprinkled. They also need specific conditions to establish: high humidity (60%+), moderate temperatures (70–85°F), and an active two-spotted spider mite population to feed on. Outdoor pachysandra typically doesn’t hold those conditions, and if a different pest or spider mite is behind the decline, persimilis won’t establish regardless.
If you can send close-up photos of the affected leaves (undersides especially), we’re happy to help figure out what’s actually going on.
So far so good! I've seen Less webbing and little red mites indicating that the spider mites are being eaten. Karen, who I have been back and forth with email, has been a treat to deal with! She is incredibly knowledgeable and not afraid to share that knowledge even on a beginner level with me. I have also decided to exclusively start using beneficials instead of sprays thanks to my experience and her help.
All in all this has been above expectations on every department!
Works well
It was fast delivery, I'm pretty sure that it was only 3-4 days after buying thatI received them. They got the job done! will definitely recommend this nursery to my plant friends and family! Also buying again if needed.!
Very active. Making progress, but time will tell for the spider mites.
I ordered some mites later in the day Wednesday afternoon, I wasn't sure 8f it would ship out that week because of the later order. My order was at my front door Thursday before noon, I will absolutely use this company again and recommend to everyone I know needing help with spidermite.
Can I buy these any where walking in
Hi,
Probably not. They have a very limited shelf life and eat only two-spotted spider mites, which makes keeping them in a physical retail environment very challenging. Please let us know if you find anywhere and we'll refer people there who prefer the physical retail experience!
Pairs well with
Small things that help them work
-
Add alongside
Neoseiulus californicus
The plant after the outbreak.
from $75
-
Add alongside
Ultimate Control Predatory Mite Mix
Every pest that is not a spider mite.
from $90
-
Add alongside
Special Blend Slow-Release Prevention Sachets
Keeping it from starting again.
$5
-
Add alongside
Root Network
For the roots: mycorrhizae and microbes that help roots take up water and nutrients. Use at repotting, then a monthly drench.
from $15
More to know
Ways to buy, questions and reading
Ways to buy
Once, on a schedule, with friends, or mixed with other predators.
- One time
- A single bottle, this once. Free shipping on orders of $30 or more, $15 under that.
- On a schedule
- 10% off your first box, 15% off every box after. Skip, move, pause or cancel from your account.
- Group order
- Friends each pick what they want, and it ships to you in one box.
- Mix and match
- Buy several predators together and they get cheaper.
For the curious
Everything else we know about them. Tap a topic to open it.
Is this your pest?
Persimilis treats exactly one pest. If what you have is not two-spotted spider mite, the product you want is a different one.
Fine webbing strung between leaf edges and growing tips, and a dusty, speckled look to the foliage that goes bronze under pressure. The mites themselves live on the leaf undersides.
Persimilis takes two-spotted spider mite at every stage — eggs, nymphs and adults. It is slightly larger than its prey, tear-drop shaped and bright orange, and it moves fast. It walks straight into webbing that traps other predators and works the colony from the inside. It takes nothing else: no pollen, no debris, no alternative menu.
Then: is persimilis the right answer to it?
Choose this if
Choose persimilis when you can already see the problem — webbing, bronzing, a colony spreading — and you want it stopped. It is the fastest thing in the catalog against two-spotted spider mite, and the single-mindedness is why: it never stops to graze on anything else. Give it 60% relative humidity or better and it can outpace the colony.
Choose something else if
Two things rule it out. Dry air: the eggs hatch best above 60% RH, which is how the population builds — Neoseiulus californicus is the one that holds down to 40%. A clean plant: persimilis is an obligate predator and starves within days without spider mites, so it cannot be released preventatively. For prevention, Amblyseius andersoni or a sachet.
What it kills, and what it won't
There is no bonus list here, and that is the point. Persimilis eats spider mites or it dies, which is exactly why it works a colony faster than a generalist that stops to eat pollen on the way.
How it works
What it does to the pest, what it does on the plant, and what that leaves you looking at.
It goes into the web
Persimilis is a predator — not a poison, not a repellent, nothing systemic. Spider mite webbing is a defense that traps most predators at the edge; persimilis navigates it and hunts the colony from inside. There is no residue on the plant afterwards, no re-entry interval, and spider mites cannot develop resistance to being eaten.
It breeds faster than they do
What you release is the start of the population, not the whole of it. In humid conditions persimilis lays on the leaf and out-reproduces the colony it is eating, which is the mechanism that turns a release into a collapse. The eggs hatch best above 60% humidity, which is what drives that mechanism; in drier air the adults keep feeding.
Then it disappears
When the spider mites are gone, persimilis starves. That is the design and not a defect — it is what an obligate specialist does. If your predators vanish once the pests do, the job finished.
It is not a knockdown in the spray sense. The stippling already on a leaf is permanent damage and stays there whatever happens next. Webbing stops expanding first; counts drop after; new growth comes in clean last.
About persimilis
A predatory mite slightly larger than its prey, bright orange and fast, that hunts on leaves. It has no interest in your plant and no interest in you — it eats two-spotted spider mites, and when there are none left it dies out.
New to beneficials?
Five things that catch almost everyone the first time.
What arrives
Loose mites in a wood chip carrier, mixed stages. Everything in the bottle goes onto the plant — the carrier is part of the release, not packaging to discard.
You may not see them, and that's normal. Release them the day they arrive and watch the spider mites instead.
Release on arrival. Loose mites do best released rather than held — open the bottle the day it lands.
When it ships, and when it lands
Shipping
We ship when they're ready to travel. Live orders go out Monday to Thursday. If a colony needs a beat to peak, or we're propagating a fresh batch, yours might hold up to a week. All mites and insects ship 2-day or Overnight depending on what's best for them.
When it lands
Open it that day. Aim at the webbing — hot spots first, clean plants never. Tip the carrier in small piles wherever it will sit still for a few hours, as close to the damage as you can: the flat top of a leaf, the spot where a leaf meets its stem, or a small paper cup tucked into the plant. The mites walk out on their own and find the spider mites, undersides included. You don't need to reach them. Leave the material where it lands, and don't water it in.
Why we pack extra
Two days in a van is a long trip for something this small, so we send more than you paid for.
A predatory mite is the size of a grain of table salt. It ships in a bottle, in a van, for two days.
A trip like that is hard on anything this small, so we price it in: the number on the label gets counted out, and then roughly 15% more goes in on top as a cushion.
Your 500-mite bottle leaves here holding more than 500. The cushion is on us.
If you can see them
Ladybugs, lacewing larvae, Orius — the minute pirate bug — and the beetles. These are the ones big enough to see.
Cold insects are very good at sitting still. That's normal. Release them as this page says, and watch the pest instead.
Something look wrong? Email info@fgmnnursery.com with your order number.
If you can't see them
Mites, nematodes, eggs — most of what we sell, this one included. Mites this small can't be judged by eye in a bottle of carrier, so there is nothing for you to check or photograph.
Email info@fgmnnursery.com and our entomologist takes you through the diagnostic instead — where the box sat, what your room was doing, and then what the pest is doing about ten days later.
Seventy-two hours from delivery, either way, with your order number. Replacement or store credit, your pick.
Questions about phytoseiulus persimilis
Will I have bugs flying around my house?
No. They stay on the plants, where their food is.
Can I use them preventatively?
Not on a clean plant. Persimilis is an obligate predator: it eats spider mites and nothing else, so with no spider mites to eat it starves within days. For prevention, hang slow-release sachets instead: persimilis sachets in a humid room, californicus sachets in a hot or dry one, and andersoni sachets where the temperature swings.
Can I use Persimilis and Californicus together?
Yes, this is actually the best strategy for long-term control. Release Persimilis on the "hotspots" to knock down the high numbers of spider mites quickly. Release Californicus on the rest of the plants to act as a slow-release patrol force that cleans up stragglers and prevents the mites from spreading back.
My plants have heavy webbing. Should I remove it first?
Yes. While Persimilis is unique because it can navigate webbing (unlike other predators), heavy webbing acts like a highway for spider mites and a barrier for everything else. We recommend using a strong stream of water or a vacuum to physically remove the bulk of the webbing before releasing your predators. This gives the Persimilis easier access to the leaf surface where the eggs are.
What happens when they eat all the spider mites?
They will starve or leave. Persimilis is an "obligate predator," meaning it cannot survive on pollen or fungus. Once the spider mite population crashes, the Persimilis population will crash shortly after because they have run out of food. If the spider mites return later in the season, you will need to re-apply.
Can I spray soaps or oils before releasing?
You must be careful. If you use an insecticidal soap or horticultural oil to knock down the webbing, you must rinse it off thoroughly with water. Horticultural oil is done once it is dry; insecticidal soap needs a day before you release Persimilis. Residues from oils and soaps can kill the predatory mites just as easily as they kill the pests.
Why is humidity so important?
Your predators don't drink water, but absorb it from their environment. Persimilis are particularly prone to dehydration and do best in high humidity, which keeps them hydrated.
How many persimilis do I need?
Size it by the plants that have spider mites, plus any plants touching them:
- Count the plants. Every size is set at about 50 mites per 6-inch plant: X-Small covers up to 10 plants, Small 20, Medium 50, Large 100, X-Large 200 and 2X-Large 400. A big, bushy plant counts as more than one.
- Adjust for pressure. Heavy webbing or bronzing across many leaves: go one size up. A few speckled leaves and no webbing: one size down. Don't split a bottle thinner than its size; the ratio is what makes it work.
- One size is one release. Check the new growth 7 days later. If damage is still spreading on new leaves, release again; two or three releases a week apart is the normal course against an established population.
It needs spider mites to eat, so don't buy extra to keep on a clean plant; for prevention, use sachets.
Keep reading
Field Notes from the FGMN Nursery team.
Californicus or Persimilis?
One of them clears a heavy infestation faster than anything else available. The other one is still there…
Spider Mites Are on the Menu
You released the predators. Your plant still looks terrible. Here’s how to tell whether the spider mites are…
Spider Mites Brought Their Own Security
Why webbing protects the pest, and how some predators get through it
Sources
Published guidance from university extension services. The release tips on this page also draw on what we see shipping these every week.