Cobb worked for the USDA in Beltsville, MD. She was an authority on cyst nematodes, receiving samples from throughout the country for identification. Cobb identified and described a number of novel, introduced species of nematodes and worked on the development of control measures for the diseases they caused. She discovered that a race of Ditylenchus dipsaci, a stem and bulb nematode, had a much broader range than previously thought. For 10 years, Cobb also annually compiled nematology literature from around the world for the Nematology Laboratory.
(Submitted for publication in July 2008.)