Brown Needles

• Pine engraver beetles (Ips pini,) the mountain pine beetle (D. ponderosae) and the western pine beetle (Dendroctonus brevicomis) are destructive insects that attack pine forests. The invasive insects commonly attack stressed or wounded trees. These insects introduce blue stain fungi into the pine tree water transport system, plugging the pine tree's transport system and bringing about the death of the tree. Unfortunately, the tree does not exhibit symptoms of an infestation until the needles turn from green to red, signaling the death of the tree. Gardeners may notice a brown-needled tree, distinctive in a stand of healthy, green trees. Trees infected with pine engraver beetles may first exhibit brown needles on the uppermost tips of the tree branches.
  
  Carpenter ants (Camponotus spp.) are some of the largest ants found in North America. They infest damaged and decayed pine trees, establishing large colonies. Carpenter ants do not directly damage the tree. They establish nests in rotted or soft wood.
  
  Drought stressed pine trees are prone to insect attack. The best defense against insect infestation is to maintain adequate moisture levels during times of prolonged drought. Remove dead or dying trees. Burn or properly dispose of all slash, branches and needles to help prevent infestation of nearby healthy trees.
  
  

Wounded Bark and Foliage

• Deer can cause extensive damage to pine trees. They rub their antlers on the bark during mating season. They rub off the outer bark, allowing insects, fungi and disease to infest the tree. Deer also nibble on the tender new growth of pine trees, eating foliage as high as they can reach. Trim lower branches. If the tree is well established, browsing deer may damage a tree, but the tree will usually survive.
  
  

Pitch Tubes and Resin Masses

• Considered the most destructive insect to pine trees in the southern and southeastern regions of the United States, the southern pine beetle (Dendroctonus frontalis Zimmermann) lives on the inner bark of pine trees. Pine trees under attack from the southern pine beetle exhibit resin masses or pitch tubes on their exterior tree bark. Once a pine tree is infested by the southern pine beetle, the death of the tree is imminent. The southern pine beetle attacks all species of pine trees. There are no effective methods of treatment or control.
  
  The pine shoot beetle is evidenced by masses of pine pitch on the tip of the buds. Prevalent in the midwest and northeastern regions of the the United States, the pine shoot beetle is the developed larva of a brownish-red moth that lays it eggs and hibernates in the tender tips of pine needles. In spring, the moth emerges to feed on other healthy tips. The tips of the tree shrivel and die. The only known remedy for an infestation of pine shoot beetle is to engage the services of a professional arborist to remove all of the sticky tips from the tree.
  
  

Drooping, Dropping Needles and Dead Branches

• Pine wilt disease, caused by the pinewood nematode, is often found in Scots, Austrian and Red pine trees. White pine trees are not affected. White pine may succumb to a newly identified malady, white pine decline. Affected white pines may evidence different symptoms. They may appear healthy for decades and then start to decline. All conifers normally shed their oldest leaves in the fall. White pine trees that shed an abnormal number of needles, especially in the spring or summer, are likely suffering from white pine decline. Trees experiencing white pine decline present yellowing or dull green foliage.