Azalea pests such as caterpillars, lacebugs, weevils, and mites rarely bother mature and well-mulched plants. Your first line of defense is giving your azalea what it needs: a nice acid-based soil, good mulching, and possibly a little fertilizer. Occasionally, however, younger plants many suffer from infestations. If you can’t locate your azalea pests below, check our page on azalea diseases.
| Symptom |
Pests and Treatment |
| Leaves irregularly chewed. Plant wilts. |
Root weevils. Damage from the adults is usually just a few chewed leaves. The larvae, however, burrow into the ground and eat the roots and can cause severe damage. If you want to use a synthetic spray use acephate to get ride of the adults and discourage egg-laying. Want to use an organic bug-killer? Use fresh beneficial Nematodes on the soil to eliminate the next generation of weevils. Nematodes are small microscopic worms that occur naturally and will feed on the larvae of azalea pests. |
| Pale, speckled leaves almost gray in color. |
Azalea Lace Bug. Lace bugs have needle-like mouths and suck the sap from your plant. Adults lay their eggs inside leaves and seal them in for the winter. Look at the bottom of your leaves. If you see any black “fly” specks, then you already have them hibernating in your plant. If your infestation is light, try first spraying with an insecticidal soap, but be sure to cover all surfaces. If your problem gets worse, try a systemic like Bayer Garden Control. This is a systemic poison that doesn’t harm the plant, but does harm the insects. Use as directed. |
| Leaves turn bronze or grey-green. |
Mites. To tell if you have these azalea pests, simply take a white sheet of paper and wipe it along the bottom of several leaves. If you have red streaks on the paper, you’ve got mites. Mites suck the sap from your plant. For natural methods try treating with Insecticidal soaps or a horticultural oil. Otherwise, try a spray insecticide. |
| Bump-like bugs on leaves or stems. |
Scales. Both adult and nymphs (immature scales) suck plant sap. Adult females are often found in the forks of branches and on twigs. Light infestations can simply be scraped off. Spray in early spring with a dormant oil before plant growth starts. Spray insecticides can be used on the nymphs, but they are not generally effective against the adults. Use a systemic poison applied at the root of the plant. |
| Leaves are eaten/disappear. |
Red Headed Azalea Caterpillars are black with red faces and white striping. These caterpillars feed in groups and literally graze their way through your plant in late summer. When bothered, they raise up on both ends. Removal by hand is your first defense. For chemical control, try a multi-insect killer or systemic. |
| Branches are stunted, turn brown and die. |
Rhododendron Borer. Rhododendrons are closely related to azaleas, and this borer likes azaleas just as well. The adult looks a little bit like a wasp. The caterpillar is a yellow borer and drills into branches where it lives off of the sapwood all winter. Pruning and destroying infested branches are the only natural control method. Synthetic or chemical controls should be applied in May or June. Bonide Borer/Miner Killer or products that contain permethrin should be effective. Follow label directions carefully. |
Natural Vs. Synthetic Pesticides
As always, natural pesticides and measures should be your first choice of defense against azalea pests and diseases. But please be aware that just because these substances are “natural” doesn’t mean that they aren’t harmful! Be sure to follow all instructions on the container. If, however, you decide to use a synthetic (chemical) pesticide, use it sparingly. Some insects such as mites can actually develop a resistance to a poison over time.
Natural Pesticides
Azadirachtin (Neem Oil)Azadirachtin is a pesticide that comes from neem oil which in turn comes from a tropical tree (Azadirachtin indica). It disrupts the growth cycle of eggs, larvae and adults. It will work well against the majority of azalea pests: aphids, root weevils, mites, and caterpillars. Mix with water and apply as directed. Brand names include Bioneem and Rose Defense. (Be aware that although this a natural pesticide it can also disrupt the life cycle of honeybees and ladybugs.)
Horticultural Oils
Derived from petroleum oils, Horticultural oils prevent insects from breathing — smothering them. Summer application is sprayed on to prevent aphids, scales and mites from infesting the plant. Test spray an are to check how your plant will react first. Winter application is used to control the insect eggs of azalea pests.
Insecticidal Soaps
People commonly assume Insecticidal Soaps are made from soap products. Actually they are derived from potassium salts of fatty acids (from animals and plants). Works against aphids, mites, and scales. Mix first with soft or distill water and spray on. Will kill earth worms.
Beneficial Nematodes
Nematodes are small microscopic worms that occur naturally and feed on pests that live in the soil. They are especially effective against root weevils.
Synthetic Pesticides
If you must use a synthetic insecticide for your azalea pests, then I suggest you stick with Acephate for your azaleas. Acephate is a systemic poison applied at the root of your plant. The plant takes it up through its roots and protects your azalea from stem to stern. Although I mention using other spray methods above, this is my preferred chemical insecticide. It gives me full control during application, and I don’t end up spraying something I shouldn’t. It is very effective against root weevils, but can kill honeybees and birds.