Rapid, vigorous growth encourages host resistance. Pay particular attention to old, slow-growing trees, crowded groups of trees, and newly planted trees in the landscape. Large nursery stock or transplanted trees, notably oaks and pines, can become highly susceptible to bark beetles after replanting. Transplanting success depends on the tree species and its condition, appropriate tree and site selection, characteristics of the planting site, the season of the year, the transplanting method, and follow-up care. Stresses placed on a tree caused by poor planting or planting at the wrong time of year, lack of proper care afterwards, or the planting of an inappropriate species for the site will increase the tree susceptibility to bark beetle invasion.
Predators are more important in regulating bark beetle populations than parasites.
When bark beetles attack and kill some trees, natural enemies are attracted and may eventually limit the infestation. Avoid injuries to roots and trunks and protect trees from sunscald and other abiotic disorders. Irrigation may be important during dry summer months in drought years, especially with tree species that are native to regions where summer rain is common. Also, dense stands of susceptible trees should be thinned to increase their vigor and ability to withstand an attack. Irrigate when appropriate around the outer canopy, not near the trunk.