Invasive Species in a Flat World

A recent digest of US Department of Agriculture (USDA) press releases and federal register posts caught my eye. It contained five items. Individually, they seem rather ordinary, but together they tell a story. What do you notice?

• USDA Begins Survey Effort to Determine Eradication of Asian Longhorned Beetle in New York County.
• USDA Says Residents Made a Difference in Reducing Invasive Plant Pests and Diseases.
• First Shipments of Mangoes from Pakistan Arrive in the United States.
• USDA Seeks Comment on Pest Risk Analyses for the Importation of Fresh Figs, Pitaya and Pomegranates from Mexico into the Continental United States.
• USDA Seeks Comment on Proposal to Allow the Importation of Tomatoes from West African States into the Continental United States.

Here is evidence that the world really is flat—not just in the economic sense that Thomas Friedman discussed in his brilliant book (2005) “The World is Flat,” but also for invasive species.

It used to be that oceans and mountain ranges provided geographical barriers that kept the pests in one region out of other regions. Not any more. Globalization of trade and travel has flattened the mountains and built bridges across the oceans. An insect lays its egg on a tomato stem in West Africa or under the skin of a mango in Pakistan, and the larva might hatch in New York or Oregon. Likewise, a pallet made from wood infested with Asian longhorned beetle larvae supports a shipment of computer components made in China, and ends up in Washington (actually happened recently).

I know that USDA works hard to assess the risks of agricultural trade and requires mitigation measures to reduce the risks, but there is no perfect system. If you don’t believe me, take an entomologist or a plant pathologist to the produce section of your supermarket. I’m confident they’d be able to find bacteria, insects, and other live hitchhikers. Good places to look: blemishes on potatoes, brown spots on lettuce stems, and the calyx of apples. As you’d expect, organic produce is often biologically interesting. (Somebody ought to study that.)

I’m not anti-globalization. I like bananas on my cereal and grapes in the winter. But I do think we need to be smart about trade. Tomatoes imported from Africa does not sound smart to me—can’t we can grow our own closer to home? What about the customs and border inspection people, you might ask? Don’t they screen out the problems? They do catch a lot, but visual inspections at the border are not the answer. Not only are many of the pests that are coming into our country microscopic, but we only have enough inspectors to look at a small percentage of the commodities we import.

We also need research on safe, economical methods for disinfesting commodities and robust early detection and rapid response programs for the harmful pests that inevitably slip through.

Finally, we need more people that know how and when to report an unusual scale insect on an orange peel or a spider in their bananas. In Oregon, we’ve made it easy: 1-866-INVADER or http://www.oregoninvasiveshotline.org. Keep your eyes open—you can encounter exotic creatures right in your kitchen in a flat world!

Dan Hilburn