Problem: As a large state with an important agriculture industry, California is concerned about the problem of the introduction of harmful new insects. The use of pesticides may not be effective, only works if the species has already invaded, and most importantly leads to environmental contamination and unforseen side effects. A particularly virulent pest not currently well- established in California is the gypsy moth, which has severely deforested parts of the Northeast and has infested areas in the Northwest near the California border. Proposed solution: The main thrust of the California Department of Food and Agriculture is to prevent the problem before it starts. The first line of defense is a large-scale border inspection program to prevent entry of contaminated or possibly threatening plants and animals. This includes inspections of motor vehicles, as well as of ships, cargo, and other possible means of entry into the state. Penalties for violation of the pest exclusion laws are severe, and do not that an action be deliberate to find it in violation. Next, coordinated effort is made to detect any invasions that may have begun. Insect traps placed throughout the state and checked regularly alert the department to the existence of problem insects. Once a problem has been identified, an intensification of the trapping program helps to determine the size and severity of the infestation. As soon as possible, a pesticide is used on the affected area to eliminate the problem before it spreads. Evaluation: The program has been a success in some instances. An invasion of Mexican fruit flies was successfully prevented in 1983, and other fruit flies have been eradicated before developing inot a problem since. In contrast, a delay in the start of the eradication efforts greatly increased the cost and delay in attacking the problem of the Mediterranean fruit fly in 1980. In the effort against the gypsy moth, the state had identified two small areas of infestation and plans to spray these during the next hatching season. Contact: California Department of Food and Agriculture. Citation: "Battling Invasions of Insect Pests." EPA Journal, v. 11 (April 1985), pp. 3-4. Keywords: environment pest control insects gypsy moths