More than one trillion dollars’ worth of agricultural products is traded every year. But as countries buy and sell fruits, vegetables, timber and other products, they also may be putting domestic plants at risk. That’s why new standards have been issued under the International Plant Protection Treaty.

The global trade in agriculture means the food someone eats may have come from a country thousands of miles away. But as food is unloaded from ships and planes, some unwelcome visitors may find a new home. Many already have.

Take the stink bug, for example, in the United States. It’s believed to have arrived from China and finds American fruit crops delicious. Pests can also include fruit fly eggs or fungal spores. Some of the well known threats include wheat rust, African army worms, Cassava Bacterial Blight and the European Grapevine Moth.  The list goes on.

That’s where the International Plant Protection Convention comes in.

“The convention originated back in 1952. It’s been revised a couple of times – 1979 and 1997. The purpose of the convention is to develop standards for trade and plants and plant products. And it’s recognized as one of the three standard setting bodies under the World Trade Organization,” said Craig Fedchock, who’s the convention coordinator.

At the convention’s annual meeting in Rome, upgraded standards were issued for pest risk analysis. It gives greater guidance for determining whether an imported plant might be a threat to cultivated or wild plants. Fedchock said that another standard was revised regarding wood packaging material.

“Everybody in the world has probably seen a wood pallet at some time or other. Well, that pallet is made generally from wood that’s not the best quality wood. Maybe the trees are dead when being made into pallets and beetles will bore into that wood and then they’ll emerge. And they can be a devastating forest pest. And we have evidence again, being from the U.S., of something like the Asian Longhorn Beetle, which has quite a voracious appetite for certain trees. But this isn’t limited to the United States. There’s Pinewood Nematode in China. It’s around the world,” he said.

The risk of pests is growing due to the sheer amount of global trade.

“More and more things are being traded. More and more people are traveling. The risks associated with people bringing a piece of fruit or some fruit from a backyard tree to a relative in another country – that’s happening more frequently. Or new and exotic fruits and vegetables are coming from one country to another or another hemisphere to another hemisphere -- the risks increase incrementally just by the volume of trade<” he said.

He said that serious harm can be done to a country if a risk assessment is not done.

“A pest risk assessment is a valuable part of the entire process of trade to make sure that a country can protect itself, but yet ensure that anything that does get imported is safe.”

Other treaty standards are being looked at for possible revision, including guidelines for sea containers.

He said, “Sea containers contain a lot of things beyond food – sometimes farm equipment, sometimes computers or what have you. They have the little nooks and crannies. They have the corners where some pests can go and lay some eggs that go unnoticed unless it’s properly cleaned. If those pests get an opportunity through an open container door to just wander out into a new environment it can be pretty bad for the environment it’s wandering into.”

Even garbage must be monitored.

“When ships arrive in a port, garbage is an issue. Or flights coming in from another country, the trash can be a significant issue. A little fruit fly can lay its eggs in a skin of a piece of fruit ,and unless you’re really an expert looking for these things you might not ever notice that this has taken place,” he said.

It’s difficult to estimate how much damage agricultural pests do every year, but it’s believed to be in the billions. Countries that have pests may not want trading partners to know the full extent of the problem.

The coordinator of the International Plant Protection Convention said it’s easier and cheaper to prevent a pest problem than it is to get rid of one.