Pine Wilt
The term "Pine Wilt" refers to the sudden, and often unexpected, death of pines. Depending on the previous condition of the tree, this can happen quickly or may take several months.
The Cause
Pine Wilt is caused by a microscopic worm called a nematode. This worm is carried in the body of a weed boring beetle called a Pine Sawyer. This beetle bores into an already infected pine tree where it picks up the nematode. The beetle will transport the nematode as it travels from tree to tree and infects each one as it moves.
What Trees are Susceptible to Pine Wilt?
The borers are attracted to stressed trees. Being that pines are not native to our area, these trees are already under stress. The Scotch pine is most susceptible to Pine Wilt. However, some isolated cases have occurred on Austrian and White pines as well.
Pine Wilt Affects
After the borer enters and infects the tree with the nematode, the problems begin. At this point, the nematodes multiply and spread. This spread causes blockages in the tree's vascular system which prevents the flow of nutrients and water throughout the canopy. At this time, wilt symptoms develop and the tree begins to die.
Steps to Reduce Disease Incidence
Although Pine Wilt is not preventable, there are some precautions you can take to reduce the chances of your pines contracting the disease. The best defense is to keep your tree healthy. This includes proper watering, fertilizing, mulching, and various insect and fungal disease control measures.
It is also important to keep the infection out of the area. Remove any infected trees in the area and properly dispose of the wood. The stump must be removed as well. This will help prevent disease spread to other nearby pines.