1469
Bark beetles
Among evergreen forest insects, bark beetles are a very prominent problem. The most notorious of the bark beetles is the mountain pine beetle. Various forested areas throughout Colorado have sustained extensive damage from mountain pine beetle attacks.
In urban areas, however, the primary culprits are typically one of the various Ips species. Ips can frequently be found in ponderosa, lodgepole, piņon, limber, Austrian and bristlecone pines as well as spruce.
There are no insecticides that will kill beetles after they have successfully infested a tree. Permethrin and carbaryl are effective preventatives against both mountain pine beetle and Ips beetle.
 When Ips beetle infested trees are cut down, the resulting piles of slash can still harbor the insect. It takes about six weeks for Ips beetle to go through their life cycle in the piles. Ips will attack freshly cut bark that is intact and fairly moist. After they have emerged from the cut logs or the bark pulls off easily, it is no longer a source for Ips to go through their life cycle.
There are several species of secondary bark beetles that can be found in evergreens. One example is the red turpentine beetle but other genera of bark beetles include Polygraphus, Scierus and Pityokteines. Preventive sprays are typically not necessary for these beetles as tree mortality is low.
For more information, see the following Colorado State Extension fact sheet(s).
For more information, see the following Planttalk Colorado™ script(s).
| 
