Mountain laurel (Kalmia latifolia) is a beautiful, evergreen shrub native to the eastern United States known for its stunning clusters of pink, white, or red flowers. While mountain laurels are relatively low-maintenance plants, they can fall victim to a variety of pests that can damage their foliage and overall health. In this guide, we will explore some of the most common pests that affect mountain laurels, how to identify them, and the best treatment options to keep your plants healthy and thriving.
1. Azalea Caterpillars (Datana major)
Identification: Azalea caterpillars are hairy, bright yellow-green caterpillars with black and white stripes along their bodies. They are usually found in groups on the undersides of mountain laurel leaves.
Treatment: Handpick the caterpillars off the plant or spray with a botanical insecticide containing Bacillus thuringiensis (Bt) to control their population.
2. Lace Bugs (Corythucha spp.)
Identification: Lace bugs are tiny insects with lacy wings that feed on the undersides of mountain laurel leaves. Their feeding causes stippling on the foliage, giving it a whitish or yellowish appearance.
Treatment: Use insecticidal soap or horticultural oil to suffocate lace bugs or apply neem oil to repel them.
3. Scale Insects (Various Species)
Identification: Scale insects appear as small, oval-shaped bumps on the stems and leaves of mountain laurels. They can be brown, black, or white in color and secrete a sticky substance known as honeydew.
Treatment: Remove scales by hand if possible or apply horticultural oil to smother them. Systemic insecticides can also be effective against scale insects.
4. Spider Mites (Tetranychus urticae)
Identification: Spider mites are tiny arachnids that feed on the undersides of mountain laurel leaves, causing stippling and webbing. Infested leaves may turn yellow or bronzed.
Treatment: Increase humidity around the plant by misting regularly and prune infested branches. Use insecticidal soap or neem oil to control spider mite populations.
5. Leafminers (Various Species)
Identification: Leafminers are larvae of various insects that create serpentine tunnels within mountain laurel leaves. These tunnels appear as wavy lines on the foliage.
Treatment: Prune and destroy infested leaves to reduce leafminer populations. Systemic insecticides can also be used to control severe infestations.
6. Japanese Beetles (Popillia japonica)
Identification: Japanese beetles are metallic green beetles with coppery-brown wing covers that feed on the foliage and flowers of mountain laurels. Their feeding causes skeletonized leaves and wilting flowers.
Treatment: Handpick adult beetles off the plant in the early morning when they are less active. Use pheromone traps to attract and capture beetles or apply insecticidal soap to control their populations.
7. Deer
Identification: Deer are notorious for feeding on mountain laurels, especially in areas where they are abundant. Deer browsing results in clipped foliage and damaged branches.
Treatment: Install physical barriers such as fences or use deer repellents containing ingredients like garlic or capsaicin to deter deer from feeding on mountain laurels.
While preventing pests from infesting your mountain laurels is ideal, it’s essential to monitor your plants regularly for any signs of pest activity. Early detection can help you address pest issues promptly and minimize damage to your plants. By implementing appropriate treatment measures and maintaining good cultural practices, you can keep your mountain laurels healthy and vibrant throughout the growing season.