Managing hemlock woolly adelgid (HWA) can involve use of insecticides. When it does, the non-target impacts (negative effects to other organisms) need to be thoroughly considered
and weighed against the environmental cost of inaction or alternative management approaches. Insecticides applied for HWA management are used for conservation purposes, which may seem counterintuitive. However, hemlocks are a key forest species, and so their loss can result in severe ecological consequences. To justify insecticide use against HWA, we have to ask: What are the possible negative consequences of using insecticides in the forest? We must consider these trade-offs in hemlock management. It is important to remember that there will be trade-offs in any kind of resource management discussion, even if it may not initially seem apparent. The negative environmental consequences of hemlock mortality must be weighed against the known consequences of insecticide use to preserve hemlocks.

Galls are abnormal vegetative growths on trees that result from the feeding and egg laying activities of various insects and mites. Generally, galls are not life threatening to trees, but there are recommended steps to control the growth.