“…Clark et al (1967) defined this term as "the part of an ecosystem which determines the existence of a particular population -composed of the subject species and its effective environment." The concept even influenced our views of pest management, defined by Rabb (1970) as "the reduction of pest problems by actions , Curry et al 1980, and Gutierrez et al 1990a, three describing Heliothis virescens (F.) and Helicoverpa zea (Boddie) , Hartstack and Witz 1983, one of Lygus hesperus (Knight) (Gutierrez et al 1979), three of Pectinophora gossypiella (Saunders) (Gutierrez et al 1977, Stone and Gutierrez 1986, and Hutchison 1991, and one of Pseudatomoscelis seriatus (Reuter) (Hartstack and Sterling 1986). Most of these models were linked to a cotton model (Gutierrez et al 1975(Gutierrez et al , 1984(Gutierrez et al , 1990bCurry et al 1980;Jones et al 1980;Hartstack and Witz 1983;Brown et al 1983), and some were combined with models of other pest or beneficial species (Brown et al 1983.…”