Last week the Washington Invasive Species Council released an economic impact study of invasive species in Washington. The study provides “a snapshot of total economic impact within a single year if no prevention or management activities occurred.”

The three worst offenders are apple maggots, rush skeletonweed, and scotch broom.

• Apple maggot: The larvae of the fruit fly is found in 22 counties and makes apples, pears, and cherries “unfit for consumption, sale, and export.” This is a particularly interesting case because “any orchard infested with apple maggot cannot export any of their produce.” Thus, the direct costs related to fruit that would be sold domestically would be $54.2 million, while direct costs related to fruit that would be exported would be $108.3 million. Total impacts (direct, indirect, induced) would result in $392.0 million in lost business activity, 2,900 lost jobs, and $125.2 million in lost wages.
• Rush skeletonweed: A weed found in 28 counties (mostly east of the Cascades) that reduces grazing opportunities for livestock, out-competes crops for nutrients, and can damage harvesting machinery. Direct impacts to crops (wheat, potatoes, hay, legumes), livestock, and hunting would total $61.8 million. Total impacts would result in $149.2 million in lost business activity, 1,080 lost jobs, and $47.0 million in lost wages.
• Scotch broom: A shrub found in 32 counties (particularly west of the Cascades) that is toxic to livestock and elk, prevents forest regeneration, and out-competes crops for nutrients. Direct impacts to livestock, timber, and hunting would total $59.7 million. Total impacts would result in $142.8 million in lost business activity, 660 lost jobs, and $36.8 million in lost wages.

Altogether, without prevention, 23 invasive species could cause $1.3 billion in annual damage in Washington. The study doesn’t mention how much is currently spent on prevention from public and private sources, but according to the Invasive Species Council, “state agencies and universities spend more than $25 million a biennium to control invasive species.” As Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.”