Farmers in Louisiana are going toe-to-toe with some nasty enemies: apple snails that clog crawfish traps while laying millions of bubblegum-colored eggs and tiny bugs called delphacids that can wipe out half a rice field while spreading plant disease. Scientists are trying to figure out how to stop them, but the recent surge in these pests that threaten the cultural heritage of the South is still largely a mystery. Researchers are examining possible factors including farming methods, pesticides and extreme weather. They say that in general climate change is helping invasive species find footholds.
