There are many ways in which insect reproductive systems can be targeted for pest control. We will focus on two approaches that are widely used in crop management, mating disruption and the sterile insect technique. Mating disruption is a pest management tactic that exploits pheromone-based mate finding behaviors, and has been particularly effective at combating moth pests. By interfering with the mate finding process, this technique reduces successful oviposition, pest population density and hopefully pest induced damage. Mating disruption involves the application of synthetic or man-made pheromones to a management area. Atmospheric treatment with pheromones can interfere with the mate finding process by creating false pheromone trails, camouflaging the female's signal or by overstimulating the male's nervous system. The mating disruption approach works well for pests that rely on chemical signaling for mate location. It is only effective however if pest population densities are low. At high population densities, a male may find a female without the use of pheromone cues simply because there's a higher chance of encountering one. Mating disruption is environmentally friendly and is usually very specific to the targeted insect. This makes it a valuable tool in pest management because it lowers insecticide input into their ecosystem and has fewer non-target effects. Due to the high monetary costs associated with pheromone synthesis, mating disruption is mostly used to control pests in high-value crops or severe pest problems with no other suitable solution. It is a particularly valuable tool in dealing with pests of perennial crops as many cultural control strategies like crop rotation and tillage cannot be implemented. Mating disruption can also be an important tool in the management of invasive pest species. When pests are first introduced into an area, their population density is low and can be effectively managed with mating disruption. This has been implemented over large geographic areas in the United States to combat the spread of gypsy moth, a devastating invasive forest dweller that strips all of the leaves from a variety of tree and shrub species. In recent years, aerial and land-based application of pheromones to hardwood forests has helped to slow the westward expansion of gypsy moth from its point of introduction in the Eastern US. Another pest management tactic that interferes with insect reproduction is called the sterile insect technique. This pest control method aims to reduce reproduction in pest insect species by releasing large numbers of sterile individuals. The sterile insect technique is used primarily against high-risk pests of high-value crops that are geographically restricted. It is proven to be effective against pest species such as the codling moth, a pest of pears and apples as well as the screwworm, a parasite of cattle. The goal of the sterile insect technique is to eradicate the pest insects from an infested region. This approach requires a large investment of time and money. A large rearing facility is required to produce millions of individuals that are sterilized through ionizing radiation, genetic manipulation or using RNA interference to inhibit gene expression or translation. If wild pest insects mate with sterilized individuals released into the management area, it can significantly reduce the population size of the next generation. For this technique to be effective, the probability that an insect would mate with sterile individuals must be greater than that with the wild individuals. This means a high sterile to wild population ratio must be maintained in the pest management program over multiple years. As such, the sterile insect technique is an approach that requires extensive collaboration between government bodies, industry partners and landowners to rear, sterilize and release large numbers of the target species into a management zone. The expenses associated with the consistent production and transport of millions of sterilized insects for release is unsurprisingly high. Nonetheless, the economic damage from high risk pests such as the screwworm makes the costs associated with the sterile insect technique worthwhile for the effective elimination of the pest. Furthermore, this technique reduces the need for chemical insecticides and can be effective on species that are difficult to target with other pest management tactics. As it is highly specific, negative effects on non-target organisms are minimal.
