Orius insidiosus

Adult thrips — the flying, feeding, egg-laying stage that predatory mites cannot catch. Orius insidiosus, the minute pirate bug, is the only thing in our range that takes them, and it is very good at it. About 3mm, dark and shield-shaped, large enough to see, and because it flies it searches the whole grow space rather than waiting on one leaf. A single one routinely kills more thrips than it actually eats.

There is nothing to it on your end. Nothing to mix, nothing to spray, no residue on the leaves and no re-entry interval — you tip them out among the flowers and leave them to it. They go to the hot spots on their own, they reach dense plants a mite would take weeks to cross, and thrips cannot develop resistance to being hunted. Safe around people, pets and anything you plan to eat.

Two conditions decide whether it works for you. It needs light — at least 12 to 14 hours a day — or under short winter daylengths it may enter diapause and stop hunting. And it needs a reason to stay: it feeds on pollen as well as prey, so flowering plants hold it when pest numbers are low, and with the pests gone and nothing in flower it may leave to find food elsewhere.

It does not reach the soil, where most thrips drop to pupate — Sf nematodes are what handle that stage. The complete answer to thrips is three: Orius on the adults in the canopy, a predatory mite on the larvae on the leaves, and nematodes on the pupae in the soil. Pair rather than substitute.

Best for: Visible adult thrips, silvery scarring, and large dense plants where a mite struggles to reach every hot spot. 70–90°F, sluggish below 60°F.
How many: Preventatively about one per 10 sq ft; on an active infestation 1–5 per plant. Flowers first — that is where the adult thrips are.
Arrives as: A bottle of live bugs through buckwheat hulls and vermiculite, with food packed in to keep them fed in transit. Expect movement when you open it, and expect some carrier to come out with them. Deploy the day they arrive — they have a high metabolism and cannot be stored.
Watch out for: Yellow and blue sticky cards catch Orius as efficiently as they catch thrips. Pull them before release and leave them down for about a week. Release late evening or just before lights-out — under high light they fly into the lamps and the windows instead of settling on the plants.
Safe around: People, pets, plants and food crops. One may give a tiny test nip if it lands on skin — a pinprick, no venom, nothing lasting.
Not for: Thrips pupae in the soil. And not a winter release into a room on short days, unless you are running 12–14 hours of light.