Conservation Training

Introduced Plant Pathogens Threatening North American Forests

August 16, 2023

1:00 pm – 2:00 pm
Location: Webinar

Introduced plant pathogens threaten North American forests. Some arrived in the distant past: chestnut blight, white pine blister rust, beech bark disease, Dutch elm disease, butternut canker. Damaging introductions continue through the late 20th Century (sudden oak death, laurel wilt) and recent decades (ohia rust, Fusarium blight, rapid ohia death, beech leaf disease). Introduction of pathogens to naïve ecosystems is a global problem: North American and Asian pathogens are killing millions of trees in Europe.

Most of these pathogens probably entered on plant imports; others associated with ambrosia beetles could be introduced on plants, or on wood. The U.S. imported ~5 billion plants in 2021. One type of wood imports known to transport ambrosia beetles is, and wood packaging, e.g., crates and pallets. The U.S., Canada, and Mexico together import more than 31 million shipping containers per year. Between 11,000 and 25,000 of these containers are probably transporting a wood-boring pest. (While not all ambrosia beetles, this group is among the most commonly detected insects.)