Inspectors check trucks for invasive hitchhikers near Plymouth

Tri-City Herald Staff WriterMarch 21, 2014 

— State and federal inspectors were hunting for hitchhikers on trucks at the Plymouth weigh station off Interstate 82 this week.

They were looking for gypsy moths, nematodes, Japanese beetles and snails, among other pests.

These invasive pests could negatively affect the state’s agricultural and forestry industries and exports if they were to gain a foothold in the state, officials said.

Fourteen officials from the Washington State Department of Agriculture and the U.S. Department of Agriculture inspected trucks at the weigh station near the Washington and Oregon border Thursday and Friday.

Not every truck that passed through the weigh station was inspected. They were prescreened and the drivers were asked two simple questions: Where were they coming from? What was their cargo?

If the drivers were coming from a state with invasive pest species that Washington doesn’t have or were hauling agricultural commodities, then their rigs were examined. Most inspections were quick, taking minutes.

Officials also confirmed that truckers had the correct documentation to show that nursery stock had been declared free from pests and diseases from their home state.

Owen Shiozaki, Pacific Northwest supervisor for USDA’s animal and plant health inspection service, expected officials would inspect about 100 or 120 trucks at the Plymouth weigh station during the two-day emphasis patrol.

Shiozaki said the checkpoints help to remind truckers how important it is for them to keep their rigs clean. And they want truckers to know what to do if they spot signs of pests, including contacting the USDA or Department of Agriculture if there are any questions.

Officials did not end up finding any invasive pests on the rigs they checked during the two days.

Now is the time that nursery stock is brought into the state as nurseries stock up before Mother’s Day. “It’s more cost effective to stop the pest from coming here,” said Mike Louisell, a public information officer for the state Department of Agriculture,

Among the pests Washington doesn’t have or want are gypsy moths and Japanese beetles. Randy Taylor, state Department of Agriculture acting managing entomologist, said there are also invasive species of snails the state doesn’t have or want, including one that feeds on wheat.

States east of the Mississippi have permanent populations of gypsy moths, a forest pest that eats leaves and can cause problems for the forestry industry, recreation and the environment, Taylor said. Washington has had some introduced each year since the mid-1970s, but has so far managed to eradicate them.

If the state had a permanent population, it would become a trade problem, especially since the state exports forestry products and Christmas trees, Taylor said.

On some of the trucks, inspectors looked for egg masses, since gypsy moths lay eggs on items that can be moved, including machinery, bird houses and patio furniture. The egg masses, about the size of a half dollar, includes hundreds of eggs, Taylor said.

Japanese beetles are mostly an East Coast pest, but nearby states, including Oregon, Idaho, Montana, Colorado and Utah, have them too, Taylor said.

Japanese beetles are an equal opportunity eater, with adults able to feed on 300 different species of plants, including crops, Taylor said. In their grub form, they cause problems for the turf grass industries and golf courses.

Adult Japanese beetles can ride into the state on airplanes, including cargo planes, Taylor said. And grubs can come in through nursery materials.

Inspectors also were looking for nematodes, microscopic roundworms that Shiozaki said can cause problems for potato farmers. The nematodes will form scabs on potatoes, making them unsellable.

Potatoes are Washington’s fourth top commodity, valued at $700 million in 2012. Most of the potatoes are processed into frozen potato products such as french fries.

Invasive pests also can be brought into the state on out-of-state firewood, Shiozaki said. If the wood isn’t used, the pests hatch. That’s why officials recommend using wood from Washington-grown trees for fires.

Both the Department of Agriculture and USDA take other steps to try to keep pests out and detect them early so they can be eradicated before gaining a foothold.

The state puts out traps each year for invasive pests such as gypsy moths and Japanese beetles. They do surveillance at areas such as airports where pests can enter the state.

The Department of Agriculture also inspects nursery stock that is exported, said Aaron Paul, an environmental specialist with the department’s plant services program. Inspectors also will check nursery stock that has been imported to make sure it complies with quarantines.

For information on invasive pests and how to help prevent them from gaining a foothold, go to

Spot an insect that is an invasive species or you can’t identify? Call the Washington State Department of Agriculture at 1-800-443-6684, or capture the pest in a secure container and email a photo of it to

--Kristi Pihl: 582-1512;

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