Wednesday, December 5, 2012

The 2012 Grinch is a Slug

             I love the holiday season, but I’m not a big fan of the Christmas tree shipping season. There is a shipping Grinch every year. This year, it is slugs on Oregon trees arriving in Hawaii.

            Oregon has over 700 licensed Christmas tree growers. Together they produce 8 million trees a year. Ninety percent of the trees are sold out-of-state, including 900,000 to customers in foreign countries. Every country and some states have import requirements, and Oregon Department of Agriculture Nursery/Christmas tree program staff spend October through early December inspecting  trees and certifying crop for export. There are no better Christmas tree inspectors in the world, but every year the Grinch slips through the system and ruins someone’s Christmas.

            This year, it’s the Hawaii Department of Agriculture inspectors that are working overtime and dreaming of a vacation from Christmas. On first arrival in Honolulu, 40 percent of the Oregon Christmas tree containers were found to have hitchhiking slugs. A smaller number had yellow jacket queens, root weevils, and other live critters. As the season progressed, the percentage of quarantined containers declined until only 12 percent of the last shipment of 54 containers were quarantined.

            What happened? Biology and reality. Christmas trees are living organisims grown in a verdant environment. Spiders, ants, slugs, tree frogs, and lots of other animals live in Christmas tree plantations – tree are, after all, homes for many kinds of wildlife. Inspectors can spot twig weevil or needle midge infestations in fields, but a slug on a Christmas tree, especially an immature tree like the ones uses in Hawaii to celebrate the holiday season, is virtually impossible to discover. Oregon Christmas trees, though of high quality, are not sterile. In fact, they are far from it.

            The reality is that the inspection and certification process only screens out trees from unhealthy fields; it doesn’t guard against hitchhikers.

            Hawaii’s inspectors are commited to their mission of protecting their islands from invasive species. They are doing the right thing by stopping infested containers. Unfortunately for them, the demand for Christmas trees is so great that they are working overtime and weekends to hot water-wash our trees before releasing them. I feel bad about that. This kind of invasive species issue should be taken care of at origin rather than at destination.

            I’ve had it with the Shipping Grinch. We need to kick this Grinch out of our holiday. We invest a great deal of time and resources protecting Oregon from invasive species because it is important. We also need to make sure we aren’t exporting potential invaders to our customers. After all, we would expect the same from them.

            We’re going to have to figure out a better system of preventing hitchhikers from leaving Oregon on Christmas trees. There is hope. Some growers haven’t had any rejections. They are using a combination of mechanical shaking, slug baits, stacking trees on pallets, or power-washing to discourage hitchhikers. We need to figure out what’s working and turn what we learn into best management practices that all growers can follow.

            Best of luck to you for a Grinch-free Christmas! And don’t forget to thump your Christmas tree in the driveway before bringing it indoors. All the little hitchhikers that fall out with the dead needles will thank you – and so will your spouse, your neighborhood, your county, your state . . .

Dan Hilburn     


1 comment:

  1. Norway's University Museum of Bergen reports up to 25,000 individual insects in some Christmas trees. Fascinating!