Conservation of natural enemies may be an effective form of pest management in various ecosystems. If beneficial Hymenoptera, native to an area, can be protected and encouraged to multiply, the benefits of natural insect pest control might be realized. Hymenoptera as natural enemies as well as pollinators have been studied intensively in many agroecosystems worldwide. However, lowbush blueberry is not an ecosystem where ecology of Hymenoptera has been well studied. This book discusses two studies conducted in lowbush blueberry fields in Washington County, Maine (USA). These studies investigate the population dynamics of native bees and wasps, and further try to explain what environmental factors are associated with changes in abundance within and between blueberry fields. Based on the results of these studies, blueberry growers should consider integrating efforts to conserve populations of native Hymenoptera into their management practices. In doing this, growers may also want to research methods of pesticide use that will minimize lethal effects on these beneficial bees and wasps.