Yellow dogwood (Cornus sericea "Flaviramea"), more commonly known as yellow twig dogwood, is a deciduous shrub that grows best in U.S. Department of Agriculture plant hardiness zones 3 to 8. This plant is occasionally susceptible to a few insect pests, though growing it under ideal conditions will keep yellow dogwood healthy and make pest problems less likely. Scales are a large family of unusual-looking insects, with a flattened appearance that makes them look more like plant growths than living creatures. They feed on plant juices by inserting their mouth parts into twig and leaf tissue. Scales rarely cause significant damage to dogwoods and natural predators are usually enough to keep them in check. In cases of severe infestation, narrow-range insecticides applied during yellow dogwood's dormant season can be helpful. It is important to first identify the species of scale you are dealing with, because most insecticides only affect certain varieties. As their name suggests, leafminers borrow into plants' leaves, creating tunnels, or "mines" between the upper and lower leaf surface. They are a fairly minor pest, rarely causing significant damage, and the University of California recommends controlling them by clipping away older infested leaves. Insecticides are not very effective, but natural enemies, such as parasitic wasps, can keep leafminers in check. Bagworms are caterpillars that create brown, bag-like cocoons hanging from infested trees. These caterpillars usually infest conifers and cocoons can easily be mistaken for pine cones, but they are fairly easy to spot on dogwoods and other deciduous trees. Bagworms can feed on the leaves of yellow dogwood and cause significant defoliation in severe cases. Hand-picking caterpillars and cocoons often provides sufficient control, but a number of insecticides are also effective, including carbaryl and Bacillus thuringiensis. Maintaining healthy plants greatly increases their resistance to insect pests, and yellow dogwood is no exception. This shrub grows well in full sun, though a small amount of shade is preferable in hot climates. Yellow dogwood prefers moist soil rich in organic matter. Well-drained soil is preferable, but the plant can also tolerate swampy or boggy sites.