BeneficialWestern flower thrips
Swirski mite for western flower thrips
Amblyseius swirskii · predatory mite
Against western flower thrips
It eats the youngest larvae, not the adults, so it lowers the next generation rather than today's damage — which is why it goes in before damage is visible. Warmth decides whether it works: UConn found it out-performed N. cucumeris in warm, long summer days, while in short winter days both controlled thrips and the cheaper cucumeris made more sense. Below about 18 °C it is not effective.
Rate25 /m² preventive, 50 at first detection, 100–300 on hot spots (Cornell); sachets repeated after four weeks
TimingFrom early in the crop, while thrips counts are still low
Temperature20–32 °C best; not effective below 18 °C (Biobest: 15 °C)
macro · swirski mite on western flower thrips
The pestWestern flower thripsFrankliniella occidentalisSilvered scars, black frass specks, flecked petalsFull pest profile →Before you order
Sprinkled onto the leaves or hung in slow-release sachets in warm crops, where it feeds on pollen as well as prey and can build up ahead of the pest. How it works, how to tell it has established and the supplier list are on the full Amblyseius swirskii profile.
Release calculator
How many do I need?
Area and infestation level in; quantity, cost and a weekly schedule out. Open the calculator →
Other controls for western flower thrips
- Amblyseius cucumerisPredatory mite · 50–100 /m² per release (Koppert); UC IPM: 10–50 mites per plant, weekly; or sachets
- Orius insidiosusPredatory bug · 1–2 /m² per release; up to 10 /m² in hot spots
- Orius laevigatusPredatory bug · 0.5–1 /m² preventive once the crop flowers; 5–10 /m² in and around hot spots
- Stratiolaelaps scimitusPredatory mite · 100–500 /m² of compost surface per release (Koppert); once at planting (UConn) or repeated once or twice (Koppert)
- Metarhizium brunneum strain F52Microbial — insect-killing fungus · Label rate — granules 1.5–3 lb per cubic yard of potting mix; liquid drench 4–8 fl oz per 10 gal
- Beauveria bassiana strain GHAMicrobial insecticide (fungus) · Label rate — 1–2 qt per 100 gal (BotaniGard ES / Mycotrol ES) or 1–2 lb (22WP)