 From VOA Learning English, this is the Agriculture Report. Agriculture is a big business. More than $1 trillion worth of agricultural products are traded internationally every year. But countries may put their own plants at risk when they import fruits, vegetables, wood and other products. As products are unloaded from ships and planes, some unwelcome visitors may find a new home. The stink bug is one example. This pest eats fruit crops. It is believed to have arrived in the United States from China. Other pests include fruit fly eggs or fungal spores. Some well-known threats include wheat rust, African army worms, cassava bacterial blight and the European grapevine moth. The list goes on. To fight the problem, there are new standards under the International Plant Protection Convention. Craig Fedchok is the coordinator of the treaty. He says the purpose of the convention is to develop standards for the trade of plants and plant products. The convention was first approved in 1952. It is recognized as one of the three bodies that set standards for the World Trade Organization. New standards for pest risk analysis were released at the convention's annual meeting in Rome. These give greater guidance for deciding whether an imported plant might be a threat to cultivated or wild plants. Craig Fedchok says changes were also made to standards for wood packaging material. Wood packaging can carry pests like beetles that can harm native forests. Agricultural pests are believed to cause billions of dollars in damage each year. Finding an estimate is difficult. Countries may not want their trading partners to know the full extent of the problem. For VOA Learning English, I'm Alex Spillareo.