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

Problem Identifier Unit Screen//v.w/ RR Template Spruce Spider Mite

Problem
Needles are stippled yellow, and are dirty. Sometimes there is a silken webbing on the twigs and needles. To determine if the tree is infested with mites, hold a sheet of white paper underneath some stippled needles and tap the foliage sharply. Tiny dark red, green, or black specks the size of pepper grains will drop to the paper and begin to crawl around. The pests are easily seen against the white background.

Analysis
(Oligonychus ununguis)

The spruce spider mite is one of the most damaging pests of evergreen trees. These mites suck sap from the undersides of the needles. As a result of feeding, the green leaf pigment disappears, producing the stippled appearance. This symptom may be mistaken for certain types of air pollution damage (see PAN). Spider mites first appear between April and June, hatching from eggs laid at the base of pine needles the previous fall. Mites can rapidly build up to tremendous numbers during the growing season. Young pine trees may die the first season. If left uncontrolled for several years, older trees sometimes die, with symptoms progressing from the lower branches upward. Several other species of mites also infest pines on the West Coast. Some of these mites are most numerous in the spring, while others are found throughout the summer and fall.

Solution
Spray with a miticide containing hexakis. Repeat the application 2 more times at intervals of 7 to 10 days. Additional sprays may be needed later in the season or in spring if the tree becomes reinfested.

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