Data on adults reared from eggs collected from cotton fields in the Stoneville area indicated the predominant Heliothis species was H. virescens (F.) for the 4-year period 1984-1983. This was reversed for the period 1984-1985 with the predominant species being H. zea (Boddie). Adults reared from larvae collected in the same fields were predominantly H. zea in 1980-1981 and 1984-1985, and H. virescens in 1982-1983. The importance of making accurate species identifications before applying control measures is pointed out.