A plane released 100 gallons of pesticide on the city of Fargo last night. It was the area's first aerial spraying for mosquitoes in almost 20 years. Heavy rain in North Dakota has led to a dramatic increase in the number of mosquitoes, prompting worries about the spread of West Nile virus. While pesticides have long been the preferred way to keep mosquitoes in check, the U.S. Agriculture Department is looking at using diseases to kill the bugs and slow the infection-rate of mosquito-borne illnesses. At an Agriculture Department lab in Gainesville, Florida, research entomologist Jim Becnel is working on what he calls "bug bioterrorism." Becnel says naturally-occuring diseases can be used to control pest populations.