Insects

Pine Shoot Beetles

Pine Shoot Beetles
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Pine Shoot Beetles black or dark brown, 1/8 – 2 inches long, with a cylindrical body, rounded at the head and abdomen ends. There is one generation per year, with most adults dying after matting normally. After laying eggs in the holes (holes are called galleries), the adult comes out and then dies. The larvae soon come out to feed in separate galleries (hole like tunnels) from April through June. In May or June, larvae pupate at the end of their feeding galleries. The new generation come out through the bark and attacks new shoots on pine trees of all ages. Feeding adults attack living pine trees of all sizes. This is the most destructive stage of the life cycle. When shoot feeding is severe, tree height and diameter growth are reduced. The beetles damage the new growth by burrowing up to 4 inches into the pith (soft or spongy tissue in plants). Affected shoots droop, turn yellow, and fall off during the summer and fall. In October, the adults move into the soil or the base of pine trees to overwinter. While adults can live overwinter in shoots in warmer climates, they must move under the bark at the base of trees or in the soil in colder weather.
Pine shoot beetles were introduced accidentally to northeastern North America, where it has become a serious foreign pest of pines. Although the beetle is slow moving, it could spread to other areas through the movement of Christmas trees, nursery stock, and pine logs.