Under relentless global population growth the key challenge is to increase agricultural production while preserving biodiversity and reducing the pressure on ecosystems and natural resources. As a first step, the development of sustainable agricultural practices requires thorough understanding of all biodiversity components and their interlinkages in agricultural and natural environments. This chapter outlines how the application of taxonomic expertise can successfully resolve important agricultural pest problems. The chapter describes the development of the insect collection at the International Institute of Tropical Agriculture (IITA) and offers specific examples to demonstrate the importance of an accurate diagnosis. The chapter considers how best to exploit scientific collections, reviewing new challenges and opportunities and the importance of protecting as well as using biodiversity.