Ips: The Other Pine Bark Beetles

Four species of Ips bark beetles live in the southeastern U.S., all with similar biology, ecology, and life cycles.  Ips bark beetles primarily colonize pine trees, but may also use other conifers.  Adult beetles are small (<1/4”), brown, and cylinder shaped with spines on the back end.  Male beetles enter the tree, boring to the phloem, and release chemicals that travel through the air and attract females.  These females arrive, mate, complete gallery construction with the male, and lay eggs in the gallery.  Larvae feed in the phloem, and exit the tree when development is complete.  In the Deep South, Ips bark beetles can have 8-10 generations per year.  These beetles generally do not attack healthy trees – rather, they are attracted to trees that are already stressed, weakened, injured, or dying.  Direct control using insecticides may be possible for high-value trees, while stand management tactics that promote healthy forests will minimize risk in other areas.