Orius laevigatus
The European minute pirate bug: a small black-and-white predatory bug with red eyes, a Palaearctic species found naturally in coastal areas. It is sold across Europe for thrips in flowering greenhouse crops such as sweet pepper, strawberry and aubergine. Its suppliers are European; Koppert's US range carries the native Orius insidiosus instead. Adults take every thrips stage, including adults, and live on pollen when thrips are scarce.
At a glance
- Mode
- Predator — adults and nymphs
- Rate
- 0.5–1 /m² preventive; 5–10 /m² hot spots
- Ships as
- 500–2,000 in buckwheat and vermiculite
- Temp
- Best 18–25 °C (Biobest); above 20 °C (Koppert); min 15 °C
- Humidity
- Around 70% RH
- Sold in
- Europe; Koppert US sells O. insidiosus
How it works
The bug finds prey by touch, grips it with its front legs, pushes in its beak and drains it, and it often kills more than it needs. Adults eat every thrips stage, while young nymphs take only larvae. Koppert says a nymph eats about 54 western flower thrips over its development, and an adult female up to 20 thrips nymphs or six to seven adults a day. Biobest's figures are close. It also eats aphids, spider mites, whitefly and moth eggs, and it survives on pollen, which is why it is introduced preventively into pollen-bearing crops as soon as they flower.
Females lay one to three eggs a day into petioles, stems or leaf veins. The eggs hatch after about five days. At 25 °C the first four nymphal stages take two to three days each and the fifth four to five, so egg to adult is about three weeks, longer in the cold. Adults live three to four weeks. Short days affect it less than they affect O. insidiosus: Tommasini and van Lenteren found that part of a northern Italian strain entered a weak reproductive diapause, while a Sicilian strain was only quiescent. That matters because western flower thrips itself does not diapause.
Is it established?
What a working release looks like. Check flowers, where the bugs feed on pollen and thrips.
- DAY 1Dark adults with pale wing patches in the flowers near each release pile
- WEEK 1Newly hatched nymphs, colourless then yellow, with red eyes
- WEEK 3Nymphs darkening towards adult colour; a new generation of adults
- AFTERBugs present in flowers even with few thrips; release once or twice more if not
Release & handling
Bugs arrive as adults and nymphs in a bottle of buckwheat hulls and vermiculite. Release them the day they arrive. Koppert allows one to two days at 10–15 °C in the dark with the bottle on its side, and Biobest says 8–10 °C briefly.
Release the same day
Keep it in the dark. If you must wait, store dark and horizontal at 10–15 °C for no more than two days.
Shake the bottle gently
Koppert says to shake the bottle gently before use, so the bugs are spread through the carrier.
Piles of 50 or more
Put the carrier in piles on leaves, rockwool slabs or release boxes, in and around thrips hot spots.
Leave them undisturbed
Leave the piles for a few hours to a few days so the bugs can mate and spread. Repeat once or twice.
Pesticide sensitivity
Biobest warns that Orius is sensitive to several pesticides. The insect growth regulator teflubenzuron, for one, can badly affect a population. Check each product before spraying. Check a product →
When to choose something else
In Europe this is the standard thrips bug for flowering crops. Choose something else when:
- You grow in the US — Koppert's US range sells the native Orius insidiosus
- The crop is cucumber, which gives no pollen — Biobest uses O. majusculus there, in summer only
- The crop is tomato — Koppert advises against Orius in tomato
- There are no flowers yet — without pollen the bugs cannot build up ahead of thrips; start with predatory mites
- Temperatures run above 30 °C — Koppert says the bug is less effective
Where to buy
Suppliers of Orius laevigatus listed alphabetically, not ranked. All the suppliers found are European. helpfulbugs takes no commission and does not sell insects.
- Biobest (Orius-System)500 / 2,000EU / UK
- Dragonfli (Thrip Adult Killer)500 / 1,000 / 2,000UK
- Koppert (Thripor-L)500 / 2,000EU / GLOBAL
Orius laevigatus by target
Rate and timing differ by what you are releasing it against. Each page below is the program for one pest.