Pine wilt

Definition

A lethal vascular disease of pines (Pinus spp.) and some other conifers caused by the pine wood nematode Bursaphelenchus xylophilus, transmitted primarily by cerambycid beetles of the genus Monochamus. The nematodes migrate from the beetle vector into resin canals, then throughout the xylem, inducing cavitation and rapid wilting, resin depletion, and tree death within weeks of infection. The disease is native to North America but invasive in East Asia and Europe, where susceptible exotic pines suffer near-total mortality.

Etymology

Example

In Japan, Monochamus alternatus beetles emerge from dead pine trees in summer carrying thousands of Bursaphelenchus xylophilus dauer larvae in their tracheae; when feeding on healthy pines, the beetles introduce nematodes through feeding wounds, initiating pine wilt that kills the tree before autumn.

Synonyms

• pine wilt disease
• pine wood nematode disease

Related Terms

• Bursaphelenchus xylophilus
• Monochamus
• Vector
• dauer larva
• forest entomology
• Invasive species
• xylem
• resin canal

Usage Notes

The term refers specifically to the disease syndrome, not the nematode itself (pine wood nematode) or the vector beetle. In field surveys, 'pine wilt' is diagnosed by rapid crown browning, resinosis failure, and the presence of Monochamus emergence holes. The disease exhibits marked variation in severity among Pinus species: native North American pines often tolerate infection, while Asian and European species typically succumb. Do not confuse with diplodia blight or other pine wilt–mimicking diseases.