Red Pine Pocket Mortality - Symptoms & Signs

Pockets typically start small with one to a few dead trees surrounded by trees that have reduced shoot growth and thin crowns. Each year, a few trees on the pocket edge may die and the edge of the pocket expands. Over time, pockets can become quite large; 4-acre pockets have been observed.

Pitch tubes, which are signs of attack by the red turpentine beetle, Dendroctonus valens, can be present on the lower bole of trees in the pocket margin. The wood in the vicinity of the pitch tubes and in the root collar area may be stained blue-black. Emergence holes of the pine engraver, Ips pini, are often evident on the dead trees within the pockets.

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Pitch tubes caused by feeding of the red turpentine beetle, Dendroctonus valens WDNR Photo

Blue-black discoloration caused by Leptographium spp. WDNR Photo

Emergence holes caused by the pine engraver beetle, Ips pini. WDNR Photo