World travelers
Of all the threats to urban trees, the most severe originate overseas.
Some of these “exports” are intentional; companies may forgo careful inspections which can keep dangerous “passengers” from reaching a new home. Of eleven severe pests and disease tracked by the USDA Forest Service, all but nine originated in Asia.
Still others may be accidental travelers on the wood pallets and crates that carry cargo. And some travel in the passenger cabin, or in the luggage of people arriving from overseas. Often, people will carry foods and vegetables that remind them of their former home or that evoke memories of a special trip.
All paws on deck!
The Beagle Brigade works tirelessly to sniff out people bringing plant material and food into the country. They inspect luggage at US airports, ports and border crossings. Why Beagles? They have keen sense of smell. And compared to their colleagues from USDA and Customs and Border Protection, they’re small, nonthreatening and friendly.
Closer to home
You and your neighbors might be unwitting culprits. Most of the insect pests that plague urban trees in the US arrived on imported ornamental trees and plants. Others catch a ride on firewood cut from dead, dying or otherwise infected trees.