Key Features
- Brown tips
- Sap oozes from wounds
- Black snout weevil adults
Symptoms
Adult weevils chew the twig surface in the fall and spring, causing twigs to ooze sap and turn brown in early summer. Adults are black snout-weevils. Grubs are white and legless. Injury can be a problem in sites where pines line a drive and some trees have been removed and stumps remain. Severe problems occur in Christmas tree plantations and tree nurseries when the main stems (leaders) of young plants are killed.
Biology
Adults are attracted to cut pine stumps in late April where they meet to mate. Females burrow to roots of cut stumps to lay eggs. Worm like larvae feed on these roots until they pupate in chip bark cocoons and emerge as adults in September. During the summer, adults spend days in leaf litter and nights feeding on the twigs. Adults live for two years and lay eggs during both summers.
Management Recommendations
Focus protection efforts on small, newly planted trees who are more susceptible to damage from beetles chewing on twigs. Remove stumps that serve as breeding sites prior to planting new trees. Applications of insecticide to stumps in early April can kill beetles that emerge from stumps or use stumps to meet mates. Foliar applications of insecticides in spring and late August will prevent injury to twigs. Imidacloprid applied in the fall to the soil can prevent injury the following spring and summer. Dinotefuran applied in the spring can kill adults feeding in the summer.
Effective Pesticides
Active Ingredients include: Acetamiprid, Dinotefuran, Imidacloprid, Permethrin
Resources
