Cassava Production and Pest Management: Present and Potential Threats in a Changing Environment

Cassava is attacked by a complex of arthropod pests across the tropical regions of the world where the crop is grown. Root yield losses have been recorded for several pests, including mites, mealybugs, whiteflies, hornworm, lacebugs, thrips and burrower bugs. Agronomic characteristics such as vegetative propagation, a long growth cycle, drought tolerance, staggered planting dates and intercropping contribute to the considerable diversity of pests that feed on the crop. The dynamics of cassava production are evolving as trends in the food, feed and industrial starch sector are leading to an increased demand for high quality starches. The resulting shift to larger scale production units, expansion of cultivated area and modifications in crop management combined with the effects of climate change, especially warmer temperatures and altered rainfall patterns, affect the occurrence and dynamics of arthropod pests in cassava agro ecosystems. Data is presented to describe the effects of temperature and dry seasons on key pest species. Whiteflies, mites and mealybugs register a suitability increase in the same areas in South America: Northeastern Brazil, Northern Argentina, South-Central Bolivia, and Southwest Peru. In Africa increases are projected in Southeast Africa and Madagascar. In Asia, regions with greater projected suitability for these pest species are Coastal India and Southeast Asia. Future trends and important criteria that will influence the severity and management of key pests are discussed.