California Red Scale

 

California Red Scale is a very important pest on California citrus. Lemon is most susceptible, followed by grapefruit, Valencia orange, navel orange, and Mandarin orange. Grapes, holly, olives, roses, eucalyptus, mulberry, and walnuts can also be attacked. After eggs hatch (a female produces 100-150), the tiny “crawlers” (about ½ the size of the period over this i) spread out over the plant. This usually happens in spring or early summer. During the crawler stage scale may be spread to new plants on the feet of birds, on insects, and by the wind. They crawl for a time, then settle and begin to feed on young twigs, leaves, and fruit. When they settle, they also start building a little “house” over themselves for protection. This structure is what you see on the leaves of your tree. The scales suck sap from the tree, and if high populations develop, they will cause yellowing and drop of foliage, and a gradual decline of your citrus tree. To control red scale or any scale, spray the infested tree with a “summer oil.” The action of the oil is to cover the scale and smother it. Therefore, coverage is important. Make sure all plant surfaces are covered with spray. One spray should control the population. However, check the tree occasionally and make another spray application if live scales are found.