Myoporum Thrips

What it looks like

Myoporum thrips are very small, slender insects with fringed wings. Adults are dark brown to black and about 1/10 inch long. They feed only on myoporum, a shrub and groundcover planted widely in coastal California landscapes. Myoporum parvifolium hasn't been found with them.

The life cycle goes from egg to two feeding larval stages, then two resting pupal stages, and finally the adult. Unlike most thrips, which drop to the soil to pupate, myoporum thrips spend their whole life cycle inside the curled leaves they cause. There are several generations a year, and each one can take about 5 to 6 weeks, faster in warm weather.

Damage

Myoporum thrips feed on the newest leaves at the branch tips, which makes them curl, twist, and pucker into tight galls. Badly infested shrubs look stunted and thin, lose their leaves, and can die.

The thrips are hard to see, so the curled leaf tips are usually the first sign.

How nematodes help

Myoporum thrips are a difficult pest to control. Because they live inside the curled leaves, sprays have a hard time reaching them, and the soil-dwelling stage that nematodes usually attack is mostly missing. The beneficial nematodes in BioLogic's products kill thrips they can reach, so they work best as part of a plan:

1. Prune off the curled leaf tips, bag them, and throw them away (don't compost them). This removes many of the thrips. Don't cut back too hard, though: heavy pruning stresses myoporum and can kill it.
2. Apply nematodes to the leaves and the soil under the plant to catch thrips on the new growth and any that drop to the ground.
3. Repeat to catch new thrips as they hatch.

How to apply

After pruning, apply Scanmask at dusk, when it's cool and humid, spraying the leaves and the soil under the plants. Repeat 3 times, 7 to 10 days apart, and keep watching the new growth for curled tips.

See How to apply for step-by-step directions, or use the calculator on the Scanmask Spray page to see how much you need.