Scales of Japanese Maple

Disease Information


Symptoms and damage

the most common insect pests of camellia are scales. Scale insects feed on plants by piercing plant tissue and sucking sap. Scales do not look like typical insects. They are small, immobile and have no visible legs. They vary in appearance depending on species and sex. Some look like small fish scales attached to the plant. As a result of their unusual appearance, populations can reach damaging levels before they are noticed. On camellia, scales usually attach to leaves but some species also attach to stems. Their feeding weakens the plant. With a heavy infestation, symptoms include yellowing of the upper leaf surface, fewer and smaller blossoms, leaf drop, twig dieback and sometimes death. Tea scale (Fioriniatheae) is the most serious scale insect on camellia.


With a light infestation, scales can be scraped off the plant and discarded. If only a few leaves are infested, hand picking and destruction of infested leaves is very effective. The best time to spray with refined horticultural oil is in spring, after the plants have finished blooming and the danger of cold weather has passed. This will kill many adults, crawlers and eggs by smothering them. ΒΆ Apply horticultural oil sprays at a 2% solution (5 tablespoons oil per gallon of water). Spray the plants thoroughly, so that the oil spray drips or "runs off" from the upper and under sides of leaves, twigs, and plant stems. Spraying horticultural oil later during the growing season will help control crawlers, as well as adults and eggs. Spray two applications, 10 days apart. Spray when the temperature is between 45 and 90 degrees, and spray in the evening. Spray when no rain is in the forecast for 24 hours.

Most contact insecticides are effective only against the crawlers. In addition, using a contact insecticide against scales can result in the deaths of naturallyfested leaves is very effective

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