Pine Wilt Nematode

Asked January 26, 2014, 1:50 PM EST

A tree service company has suggested trunk injection of a nematicide in my Austrian pines against pine wilt nematode which has recently appeared in a few trees in my neighborhood. The cost is $1048 and the injection is said to last 2 years. Is it worth it?

Arapahoe County Colorado

1 Response

Pine wilt, a disease caused by the pinewood nematode, is a small worm that’s transferred from tree to tree by the pine sawyer beetle. It impacts exotic pines, although Scotch pines are more susceptible than Austrian pines. Pine wilt has been confirmed in some trees in the Denver Metro area in 2012.
Did the tree service tell you about nearby Pine wilt? You can call your City Forester, and ask them to confirm any reported identifications that are near to you, and whether or not they are recommending preventative treatments in your area.
Unless your Austrian Pine has had a positive diagnosis of Pine wilt, or you can confirm any nearby identifications, such preventative measures would not be necessary. For a positive diagnosis of Pine wilt, treatment would be better than doing nothing. However, the treatments have shown to be only about 70% effective. As far as the cost and if it's worth it, only the homeowner can assess the cost/benefit of trying to save a tree. Make sure to work with only certified arborists that are licensed to diagnose/recommend treatments for trees in your area.
The US Forest Service notes: Management of pine wilt disease is primarily limited to prevention. There are no cures for pine wilt disease once a susceptible tree becomes infested with the pinewood nematode. The most effective prevention strategy is to avoid planting non-native pines, such as Scotch and Austrian pine, where the mean summer temperature is greater than 20°C (68°F). Where these non-native pines already exist, landowners can reduce susceptibility of high-value landscape trees by watering to avoid drought stress. If they discover infestations, landowners can consider removing and chipping infested trees to limit the spread to nearby susceptible trees. http://na.fs.fed.us/spfo/pubs/howtos/ht_pinewilt/pinewilt.htm