If you don't yet know what a brown marmorated stinkbug (Halyomorpha halys) is, consider yourself lucky. These invasive insects are marching their way across more and more of the United States, spoiling fruit harvests and driving homeowners crazy. The stinkbug species seems to have hitched a ride to the U.S. in the mid-1990s in a shipment of Asian goods. The earliest sightings occurred in Allentown, Pennsylvania, but in just two decades the hardy pests have spread to at least 41 states. (See a map of where stinkbugs have been detected.) Though the epicenter of the invasion still radiates from the East Coast, populations of brown marmorated stinkbugs can now be found thousands of miles away, outside of Portland, Oregon, and within the city limits of Sacramento, California. "It's a big concern. Sacramento is in the heart of a lot of big-time agriculture," said Tracy Leskey, a research entomologist with the United States Department of Agriculture who has been working to understand the threat stinkbugs pose and detect patterns in how they move. More details and video via Nat Geo.