Indiscriminate use of pesticides has led to serious concerns relating to their adverse effects on nontarget organisms, pesticide residues in food and food products, pest resurgence, development of resistance to insecticides, toxic effects on human beings, and environmental pollution (Metcalf and Luckmann, 1982). Widespread pesticide use has also led to elimination of natural enemies and, as a result, it has become practically diffi cult to control several insect species through the currently available chemical pesticides. Therefore, it is important to adopt pest control strategies that are ecologically sound, economically practical, and socially acceptable. In this context, development and deployment of natural enemies that are adapted to extremes of climatic conditions or are capable of tolerating sublethal doses of pesticides can play an important role in pest management. Recent advances in molecular biology have broadened the available techniques for genetic manipulation of arthropods for a variety of traits in species of interest (Atkinson, Pinkerton, and O’Brochta, 2001; Kramer, 2004). Release of genetically improved arthropods for suppression of pest populations has been undertaken in the past, and the possible applications of genetically modifi ed arthropods have expanded considerably (Braig and Yan, 2002). Incorporation of foreign DNA into the genome has expanded the possibilities for genetic transformation of insects, although it has also raised a few questions. The fi rst genetically modifi ed insects were produced 20 years ago with the restoration of wild-type eye color in a mutant strain of Drosophila melanogaster Meigen (Rubin and Spradling, 1982), followed by transformation of the Mediterranean fruit fl y, Ceratitis capitata Weid. (Loukeris et al., 1995).