Protecting Austrian and Scotch pine from Zimmerman pine moth
Pines weakened by these pests are susceptible to additional pest problems.
Zimmerman pine moth can cripple Austrian and Scotch pine, making them more susceptible to Diplodia tip blight, and when they become weaker, to bark beetles. All together these pests and diseases will cause a slow decline and sometimes even death.
Austrian and Scotch pine trees can be partially protected from Zimmerman pine moth with a trunk and branch spray of permethrin, bifenthrin, cyfluthrin (all pyrethroid insecticides), or dimilin (insect growth regulator) between mid-April and mid-May. Some research is now exploring the use of soil systemic insecticides, like clothianidin (Arena), dinotefuran (Safari) or imidacloprid (Merit), to see how well they work. Soil systemics should be applied a month ahead of the desired activity time, so applications in April or early May would be active in the trees in May and June.
It is also important to grow the healthiest Austrian and Scotch Pines that you can. It is important to make sure that they are watered during dry periods. For more information see Getting ready for those early insects by Jill O’Donnell.