Do your spruce trees have clumps of dead needles? If so they may have been killed by the Spruce Needle Miner. The groups of dead needles are held together at their base by a webbing. The miner also leaves a hole near the base of each damaged needle.

The adult moths are active in June, laying eggs on the needles of spruce. During this period of time the insect is the most susceptible to insecticidal control. Once the eggs hatch and the miner gets into the needle, control is very difficult. The larvae feed actively, starting in late June until frost. They over winter as partly grown larvae in the infected needles and resume feeding in early spring until about mid-May when they enter their pupa stage.

To control the spruce needle miner, the first step is to remove the infested needles. You can hose the infected needles out of the trees by using a strong water spray. Then, clean the infected needles up and burn them. In late June, you can apply an insecticide followed by a repeat application in a week or ten days.

Malathion applied at the rate of 2 teaspoons of chemical for each gallon of water is the recommended spray for the spruce needle miner. Other insecticides labeled for needle miners such as Tempo can also be used. The active ingredient in Tempo is  available in Bayer Advanced Garden Multi-Insect Killer.  When using insecticide, mix and apply according to label directions.

This page was last updated April 2003

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