Problem Identifier Unit Screen//v.w/ RR Template

Problem Identifier Unit Screen//v.w/ RR Template Pitch Moths

Problem
One or more masses of sticky cream, yellow, or pinkish pitch appear on the trunk. These masses may be 2 or 3 inches wide and protrude 1 to 2 inches from the side of the trunk. The pitch masses are usually found in wounds or in branch crotches. When the pitch mass is scraped away, a larva up to 1 inch long may be found underneath.

Analysis
(Vespamima species)

Pitch moths attack pine, spruce, and Douglas fir. The adults are clear-winged moths that resemble yellowjackets. They lay eggs during the spring and summer in the trunks and larger limbs, particularly at sites of recent trunk injury or where old pitch masses exist. Usually there is one larva per pitch mass. It feeds on the inner bark for 1 to 2 years, pupates, and finally emerges as the adult moth during the summer. Although pitch masses are unsightly, pitch moths do not usually threaten the life of a tree. However, tree limbs may be weakened enough to break under the weight of snow.

Solution
Scrape away fresh pitch masses and kill the larva. The larva can be found in the bark under the pitch mass or in the pitch mass itself. Avoid mechanical injury to trees. Confine pruning of larger limbs to fall and early winter months.

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