Amblyseius swirskii Sachets - Slow-Release Thrips & Whitefly Prevention

What Swirskii Sachets Protect Against

Thrips, Caught Young

Western flower thrips, onion thrips, melon thrips and chilli thrips, taken as young larvae before they can grow and multiply.

Whitefly, Before It Builds

Eggs and young nymphs of greenhouse whitefly and tobacco (silverleaf) whitefly.

Small Plant-Feeding Mites

Broad mites, cyclamen mites, russet mites and some other small mites. Swirskii also eats two-spotted spider mites at low numbers, but sachets won't control an established spider mite problem; for that, use Phytoseiulus persimilis or Neoseiulus californicus.

When Pests Get Ahead of the Sachets

Sachets are for prevention. If numbers climb:

• Add bottled swirskii for a fast dose of predators.
• Bring in Orius insidiosus, a faster-acting predator that also eats adult thrips.
• For whitefly, add Encarsia formosa for greenhouse whitefly or Eretmocerus eremicus for hot spaces and tobacco whitefly.

What's Inside a Sachet

Each hanging sachet holds about 250 swirskii mites in a bran mix. Mites walk out through a built-in opening a few at a time, so plants get a steady supply of predators instead of one release. Don't cut or open the sachet.

How Swirskii Works

A. swirskii hides on leaf undersides and along the veins, ambushing young thrips and whitefly where they hatch. It can live on pollen, so the colony on your plants holds on between outbreaks instead of crashing. Young mites reach adulthood in about 7–10 days, so new generations keep coming as long as the sachet is working.

When to Hang Sachets

• Early in the warm season, before thrips or whitefly build up.
• Outdoors once temperatures stay above 68°F; sachets shelter the mites from wind and sun.
• Between treatments, to keep predators on the plants without repeated handling.

Swirskii or Cucumeris?

Let temperature decide. Swirskii sachets cover warm spaces, 68–95°F, and add whitefly control. When your space runs cooler, switch to cucumeris sachets. Around 68–80°F you can hang both.

Safe, Sustainable Pest Management

• No synthetic pesticides
• Safe around people, pets and plants when used as directed
• Safe for use on edible crops when used as directed
• No mixing or spraying

Sachet Rates

• Dense, touching canopy: hang 1 sachet per 3–6 sq. ft.
• Isolated plants: hang 1 sachet per plant.
• Replace every 2–4 weeks, sooner under heavy pest pressure.

These are general starting points. Adjust for the pest, the plant and the season, and check pests and predators regularly.

Temperature & Humidity

Effective range: 68–95°F (best 70–85°F). Humidity: 60–90%. Swirskii eggs need humidity to hatch, so a sachet in very dry air produces fewer mites.

How to Hang Swirskii Sachets

1. Pick the plants you want to protect.
2. Hang each sachet inside the canopy, touching the foliage so mites can walk onto the plant, out of direct sunlight.
3. Don't cut, puncture or open the sachet; the mites come out through the built-in opening.
4. Keep sachets from drying out, but don't hang them where they'll stay soaked, since constant dampness can grow mold.
5. Replace every 2–4 weeks.

Pro Tips

Good Bug Supplemental Diet

When pest numbers are low, hang Good Bug Supplemental Diet tabs near your sachets so predators still have food and stay on your plants. Contains shellfish (Artemia).

Chemical Compatibility

Sprayed recently? Some pesticides harm predatory mites for days or weeks after they dry. Check which chemicals are safe for predatory mites and how long to wait before you hang sachets.

Hang sachets the day they arrive. If you can't, keep them for no more than 8 hours at 55–65°F, out of direct sunlight. Never put sachets in the refrigerator, a cooler or an air-conditioned room; dry air ruins the colony inside.

How can I tell if the sachets are working?
You'll usually notice fewer pests before you notice the mites. Look for fewer new silvery thrips scars and fewer whitefly nymphs under the leaves. A hand lens helps you spot the mites, and yellow or blue sticky cards track adult pests.

Can I hang swirskii and cucumeris sachets together?
Yes. Their ranges overlap around 68–80°F, so many growers hang both through spring and fall, then switch to whichever fits the season.

Will sachets work on houseplants?
Yes, if the space stays at 68°F or warmer; 70–85°F is best. A warm sunroom, grow tent or shelf under grow lights works well.

How long does one sachet last?
Plan on replacing it every 2–4 weeks. Swap it sooner if it has dried out or gotten soaked.

I sprayed recently. How long do I wait before hanging sachets?
It depends on the product. Neem oil and insecticidal soap kill predatory mites on contact, and some pesticides stay harmful for days or weeks after they dry. Look up what you used in which chemicals are safe for predatory mites, then wait the recommended interval. Don't spray while sachets are hanging.

Are swirskii sachets safe for people, pets and plants?
When used as directed, yes. Swirskii isn't known to bite people or pets, and it doesn't feed on plants. It eats small pests and pollen, and its numbers fall once food runs out.

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