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The" green revolution" has resulted in immense increases in agricultural productivity throughout the world over the past half-century. An important part of the technological innovations accompanying this revolution is the introduction of a variety of chemicals geneiically known as" pesticides," which have been developed and widely marketed for the control or destruction of unwanted species of plants or animals that interfere with agricultural production. In recent years, pesticide use has reached massive proportions worldwide with about 2.5 million tons being applied each year (Pimentel et al., 1992), reflecting a dramatic increase in the use of these chemicals since the early 1970s. The total annual cost worldwide was estimated at US $7.7 billion in 1972, rising to over $25 billion in 1990 (1985 US dollars)(Tolba and El-Kholy, 1992). The most rapid growth has occurred in developing countries, which now account for about 20%-25% of pesticide use (Forget, 1991; McConnell and Hruska, 1993; Pimentel et al., 1992).