Pine Wilt Disease
CRITICALBursaphelenchus xylophilus
Overview
A lethal disease of pines caused by the pinewood nematode, which is transmitted by pine sawyer beetles (Monochamus spp.). It causes rapid wilting and death of susceptible pine species, particularly non-native Scots pine and Austrian pine. The nematode clogs resin canals and destroys cells lining them, leading to cessation of resin flow and rapid desiccation. Trees typically die within weeks to months of symptom onset.
- Type
- Disease
- Severity
- CRITICAL
- Source
- USFS
Symptoms
Rapid browning and wilting of entire tree within weeks, needles turn grayish-green then tan-brown but remain attached, no resin flow when bark is cut (healthy pines bleed resin), wood appears dry when cut, affects entire tree rather than individual branches, most common in mid to late summer
Affected Species
Geographic Spread
Treatments
Rapid Removal and Destruction
Remove and destroy (burn or chip) infected trees promptly before spring to prevent sawyer beetles from emerging and spreading the nematode to nearby pines. Do not store pine wood from infected trees.
Preventive Nematicide Injection
Trunk injection of abamectin (Greyhound, Arbormectin) in fall can protect high-value pines preventively. Must be applied before infection occurs. Repeat annually.
Recommended Products & Tools
Helpful supplies for managing Pine Wilt Disease. Always read and follow label directions, and confirm a diagnosis before treating.
Protectant spray for many bacterial and fungal diseases.
For the rare case sealing is advised (e.g., oaks in oak-wilt season).
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Frequently Asked Questions
What is Pine Wilt Disease?
A lethal disease of pines caused by the pinewood nematode, which is transmitted by pine sawyer beetles (Monochamus spp.). It causes rapid wilting and death of susceptible pine species, particularly non-native Scots pine and Austrian pine. The nematode clogs resin canals and destroys cells lining them, leading to cessation of resin flow and rapid desiccation. Trees typically die within weeks to months of symptom onset.
What are the symptoms of Pine Wilt Disease?
Rapid browning and wilting of entire tree within weeks, needles turn grayish-green then tan-brown but remain attached, no resin flow when bark is cut (healthy pines bleed resin), wood appears dry when cut, affects entire tree rather than individual branches, most common in mid to late summer
Where is Pine Wilt Disease currently found?
Pine Wilt Disease is currently active in Connecticut, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maryland, Michigan, Minnesota, Missouri, Nebraska, New Jersey, New York, Ohio, Pennsylvania, Virginia, Wisconsin, West Virginia. It has been reported in 19 total states across the United States.
What plants are affected by Pine Wilt Disease?
Pine Wilt Disease affects Eastern White Pine, Ponderosa Pine. Susceptibility varies by species.
How do I treat Pine Wilt Disease?
Treatment options for Pine Wilt Disease include: Rapid Removal and Destruction, Preventive Nematicide Injection. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.