Identify, prevent and treat a pest newer to the Pacific Northwest
Lace bugs look lightweight but pack a punch
- They’re about 1/8 inch long with clear wings sporting dark blotches in a lacey pattern.
- If your azaleas or rhododendrons are looking a little pale, you may have them already.
- They suck the life out of leaf tissue, along with the green color. If left unchecked they can weaken or kill a shrub over several seasons.
- Lace bugs are a relatively new pest in Oregon, first confirmed in 2009.
You can prevent infestation or treat safely to protect your prized bloomers
- Keep your plants well watered and don’t over-fertilize. Stressed and overfed plants are more susceptible to lace bugs and a variety of other problems.
- Let nature do the work for you. Ladybugs, green lacewings, minute pirate bugs, earwigs, and spiders all eat lace bugs. Encourage these beneficial bugs with a diversity of plants in your yard and steer clear of pesticides that can harm them.
- If you have azaleas or rhodies, check regularly for lace bugs. Look on the undersides of leaves. Eggs appear as black dots, nymphs look like tiny clear, yellow or black spiky things, and adults have the telltale clear wings with black blotches.
- If found, you can treat the plant with a low-risk product such as insecticidal soap, neem, or horticultural oil. Carefully follow all label directions and repeat as often as the label recommends. Typically this would be every two weeks for a few months.
- If you start scouting in spring, and start treatments as soon as you see nymphs, you can get control faster than if you start in summer since the adult insects are harder to kill.
- Avoid pesticides that can harm bees, other beneficial insects, waterways and people. Read labels and particularly avoid products containing neonicotinoids, acephate or carbaryl.
Plant resistant varieties
- When selecting new azaleas, choose varieties that are less susceptible to lace bug, such as the Encore Azalea cultivars: ‘Autumn Amethyst’, ‘Autumn Twist’, ‘Autumn Royalty’, ‘Autumn Sangria’, ‘Autumn Cheer’, and ‘Autumn Rouge’.
- Evergreen ‘Micrantha’ azalea also shows some resistance to lace bugs, as do the deciduous azaleas rhododendron canescens and r. periclymenoides.
- If you would prefer another type of shade-tolerant flowering shrub, try native Oregon grape, red flowering currant or exotic kalmia, hydrangea, osmanthus or daphne.