Mountain pine beetle

You will find lodgepole pine and other two and three-needle pines attacked in July through August when adult beetles bore into bark, introducing bluestain fungi that girdle the tree. Look for sawdust accumulation and pitch tubes or fluffy white frass at gallery entrances. Dead foliage turns reddish-brown by fall. Large beetles with teeth on the back end are clearly visible during emergence. Trees die within one to two seasons.

Remove infested trees before spring emergence of new adults and chip material. Reduce hazard tree risk by cutting beetle-killed timber promptly. Pheromone disruption is impractical for landscape trees. Prevention focuses on removing storm-damaged or drought-stressed trees. Maintain vigorous tree growth through proper irrigation.