每年通過木材航道被帶入的昆蟲對(duì)當(dāng)?shù)卣�府與戶主造成25億美元的損失。

Many wooden shipping crates that enter the U.S. contain hungry stowaways: invasive species of insects. Although these pests often dine on trees, they also devour a different resource: money.

After dividing up the invaders into three categories based on their diet—some insects bore through wood while others chew foliage or slurp sap—researchers chose the most damaging species from each category. Then they analyzed the cost of these “poster pests” to five sectors: federal and local governments, households, residential property values and timber values. The non-native bugs cost local governments a whopping $1.7 billion every year, while also gobbling up $830 million dollars in residential property values. [Juliann E. Aukema et al., "Economic Impacts of Non-Native Forest Insects in the Continental United States," in PLOS One]

To keep the ravenous insects from causing more economic damage, one of the study’s authors, Juliann Aukema of U.C. Santa Barbara, urges stronger regulations on international trade. Bug-sniffing dogs might help. After all, they have a vested interest in keeping trees healthy.

—Sophie Bushwick