Sunny days and warmer weather bring about thoughts of gardening: which plants are not performing as well as would be liked, which new ones would look better in that spot. If you are contemplating adding to your garden, be sure not to add an unwanted component: insect or mite pests (or disease) that might be tagging along with your new acquisition.
We recently received a sample from a home gardener who purchase two camellias via mail from a nursery in a southeastern state. The person who purchased the plants noticed many of the leaves were yellow, and spotted. Fortunately, she was concerned enough about a possible exotic pest that she sent the leaves to us for the problem identification.
We found an insect infesting the leaves, which was causing leaves to turn yellow and drop. The name of the insect was, appropriately, the tea scale (black, green and white tea are made from a species of Camellia) infesting the leaves. This insect does not occur in Oregon and is considered by some to be the most serious insect pest of camellia. Heavy infestations can result in little new growth, yellowing leaves, leaf drop, and general unthriftiness.
Fortunately, the person who purchased the plants destroyed the camellias before the insects had a chance to spread anywhere else in her yard.
If you purchase new plants that appear to be unhealthy, especially if they are from another state, it would be wise to consult with your local OSU County Extension office for advice on how to proceed. New plants can be fun, but new pests are a plague that could be with you longer than the plants they arrived on.
Flip image to reveal tea scales (images by S. Bambara)
Tea scale damage on camellia leaf (image by SD Frank)
Tea scale on camellia leaf (image © bugwood.org)
Close up of tea scales on camellia leaf (image by SD Frank)