There is a continuing need to increase food production, particularly in the developing countries of Asia, Africa, and Latin America. This increase in food production has to come from increased productivity of major crops grown on existing cultivable lands. One practical means of achieving greater yields is to minimize the pest-associated losses, which are estimated at 14% of the total agricultural production (Oerke et al., 1994). Insect pests, diseases, and weeds cause an estimated loss of US$243.4 billion in eight major fi eld crops (42%), out of total attainable production of $568.7 billion worldwide. Among these, insects cause an estimated loss of 90.4 billion, diseases 76.8 billion, and weeds 64.0 billion. Current crop protection costs are valued at $31 billion annually ( James, 2007). Insects not only cause direct loss to the agricultural produce, but also act as vectors of various plant pathogens. In addition, there are extra costs in the form of insecticides applied for pest control, currently valued at US$10 billion annually.