Populations of predatory arthropods in insecticide free cotton fields varied in number and species composition during the growing seasons of 1972, 1973, and 1974 though there were definite trends. In general, populations increased between June and July, peaked in late July or early Aug., and decreased sharply after mid-Aug. Populations usually peaked near or soon after the peak squaring of cotton. Many fields were without significant number of predators for control of bollworms,Heliothis zea(Boddie), andHeliothis virescens(F.), during the period of their peak population which begins in Aug. and may extend through Sept.