Phytoseiulus persimilis

Regular price $55.00

11 reviews
While uncommon, order processing can take up to 7 days depending on hatching rates and life stages.
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Phytoseiulus persimilis

At A Glance

Phytoseiulus persimilis is the gold standard for eradicating Spider Mites in high humidity environments (above 60% RH). Unlike generalist mites that eat pollen or debris, Persimilis is an "obligate predator," meaning it feeds exclusively on Two-Spotted Spider Mites. It is widely known as the "shock trooper" of biological control because of its speed and voracious appetite. These bright orange, fast-moving hunters can consume up to 35 pest eggs or 7 adults per day. If you have an active outbreak with webbing, this is your best option for rapid knockdown.

  • Scientific Name: Phytoseiulus persimilis

  • Best For: Rapid eradication of Two-Spotted Spider Mites (Tetranychus urticae).

  • Safe For: Plants, humans, and pets.

  • Key Feature: The fastest reproduction rate of any predatory mite—it can multiply faster than the spider mites it eats.

  • Environment Requirement: Must have sustained humidity above 60% to thrive. Please use Californicus or Andersoni if your humidity fluctuates.
Target Pests

Persimilis is a specialist. It targets one specific pest and does it better than anything else on the market.

  • Primary Target: Two-Spotted Spider Mite (all stages: eggs, nymphs, and adults).
  • Identification: Persimilis is slightly larger than a spider mite, tear-drop shaped, and active orange/red in color.
  • Behavior: It moves rapidly across leaves, navigating through spider mite webbing (which traps other predators) to hunt down the colony.
Environmental Needs

Persimilis is high-performance but high-maintenance. It requires specific conditions to work effectively.

  • Humidity (Critical): They require 60% Relative Humidity (RH) or higher. In dry air (<60%), their eggs will shrivel and fail to hatch.
  • Temperature: Active between 59°F - 86°F (15°C - 30°C). Ideally, keep temps below 85°F, as spider mites reproduce faster than Persimilis in extreme heat.
  • Food Source: They cannot survive without Spider Mites. Do not release them preventatively if you do not have pests; they will starve and die within days.
Selection Guide

Confused between Persimilis and Californicus? Here is the rule of thumb.

  • Choose Persimilis (The Cure): If you have visible spider mite damage, webbing, or high pest counts. You need a predator that eats fast and reproduces quickly to overtake the outbreak.
  • Choose Californicus (The Shield): Californicus eats slower but can survive on pollen and starvation for weeks. It also works in a wide range of environments and situations.
  • The "Tag Team" Strategy: Release Persimilis to knock down the hotspots and release Californicus to patrol the rest of the crop and clean up stragglers.
  • Choose Andersoni: If your temperatures are colder (below 60°F) or if you are dealing with other mite species like Russet Mites.
How to Use

Persimilis are active foliage hunters that must be applied directly to the plant structure to be effective.

  • Prep: Lightly mist your plants with water just before release. This helps the carrier material stick to the leaves and provides the high humidity these mites need to thrive.
  • Application: Gently rotate the bottle to distribute the mites evenly within the carrier. Sprinkle the material directly onto the leaves, focusing heavily on pest "hotspots."
  • Placement: Target the upper canopy and fresh growth where Spider Mites tend to congregate. Unlike other predators, Persimilis can navigate webbing, so applying directly onto spider mite webs is encouraged.
  • Urgency: Release immediately upon arrival. These mites are high-metabolism hunters with very low starvation tolerance; they cannot survive long in the packaging.
  • Frequency: A single release is often enough for light to moderate pressure. For heavier outbreaks, plan on a follow-up release 7–10 days later, and a third only if you're still seeing live mites on new growth. Once fresh leaves come in clean, the population is broken.
How They're Shipped

Packaging: Shipped in bottles with vermiculite or sawdust carrier to provide humidity and cushioning.

Viability: You should see active, fast-moving reddish mites inside the bottle upon arrival.

Storage: Release immediately. Do not store for more than 24 hours. Keep cool (50–55°F) but do not freeze.

When Your Order Arrives

Deploy day, and the weeks after.

How to deploy your order, and how to read the results over the next few weeks.

  1. 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.

  2. 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.

  3. 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 any sour smell or visible mold.

  4. 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.

  5. 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 email us.

Something visibly wrong on arrival?

Crushed packaging, sour smell, mold, or a soaked carrier — take a photo and email info@fgmnnursery.com within 24 hours of delivery with your order number. We'll replace or refund without question.

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FAQ

What is your Live Delivery Guarantee?

We guarantee that your beneficial insects will arrive healthy and ready to work. Because we are shipping live organisms, we use packaging and expedited shipping to ensure their safety. In the rare event that your order is compromised during transit, please take a photo of the package and contact us within 24 hours of delivery so we can make it right.

Can I use them preventatively?

This is the most common confusion! Persimilis is bright orange/red, pear-shaped, and moves very fast (like a sports car). Two-Spotted Spider Mites are usually pale yellow with two spots, but they can turn orange/red when they are dormant or "overwintering." If the red mite is slow and sluggish, it is likely the pest. If it is sprinting across the leaf, it is likely your Persimilis.

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 (or Andersoni) 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 and wait until the leaves are dry before releasing 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 require high humidity to stay hydrated.

Help! I'm overwhelmed

Yeah, it's a lot the first time you're using predatory mites. Please email us at info@fgmnnursery.com and we'll be happy to help!

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.
  • 5 stars: 11 (100%)
  • 4 stars: 0 (0%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
B
Blessings G.M.
Fantastic!

Fantastic! We introduced at dark and they are happily munching away.

J
Jack D.
Spider mite battle of 2026

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.

A
Anonymous
It is assumption because I did not do a microscopic examination

It is assumption because I did not do a microscopic examination.

E
Ellen B.
A great company to do business with

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.

S
Stefanie

Got my bugs quickly. Now if she just kill the spider mites on my plants.

A
Anne K.
No PHYTOS SIGHTOS - none in sight!

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.

P
Patrick K.
Less webbing and little red mites (the good guys)

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!

A
Anonymous
Works

Works well

F
Fish
It was at my door like a thief in the night.

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.!

A
Anonymous
Very active

Very active. Making progress, but time will tell for the spider mites.

J
James G.
Super fast response time.

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.

N
Nancy

Can I buy these any where walking in

FGMN Nursery

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!