Adelgids are tiny sized that look similar to aphid insects, frequently will cause unusual swellings called galls on conifer trees. Conifers are trees and shrubs that bear cones such as pine, spruce, hemlock, Douglas-fir, true fir, and many others. Adelgids feed by tapping into their host tree/shrub and withdrawing plant sap. Infestations can cause branch dieback, growth deformation, needle drop and in severe cases even death of the tree/shrub.
Notes: Good tree care can go a long way toward prevention. Avoid crowding plantings too closely. Thin out branches to open up the tree crown, but don’t top or dehorn. Keep trees wound free. Fertilize trees in the spring with a complete fertilizer. Water trees deeply during dry spells.