Dennis from Dillon, Co writes
The trees are at 9200' in Colorado. How much Acephate should I buy to apply next spring? How is it applied?
Acephate 97UP is not labeled to control white pine weevils. The standard approach to manage white pine weevil is to spray insecticides in spring. This treatment is directed at the overwintered adults to kill them before they lay eggs. Current insecticides useful for this treatment would include products that contain bifenthrin (Talstar), cyfluthrin (Tempo) or permethrin (Tengard). Rates of use should be to the high-end of what is labeled, such as for bark beetles or borers. Timing is very important but difficult to determine. Sprays should be applied shortly before adults begin to feed on the terminal and lay eggs. You can contact your local cooperative extension office and speak to the master gardener on staff who can help you determine the correct timing. Treatment of the top of the tree during midsummer, after adults have emerged from the wilted terminals, can kill weevils as they feed in this site, reducing overall numbers that may cause problems in the subsequent year. Also, as many weevils crawl to the trees in spring, treatment of the lower trunk at the same time spring terminal applications are made may also help kill some of the migrating overwintered insects.
Answer last updated on: 09/03/2014