Elucidating Tuta absoluta(Meyrick) invasion and enhancing itsmanagement inEastern Africa: spread, socio-ecological impacts, andpotential of a newly importedlarval parasitoid for classical biologicalcontrolEastern in Africa

Abstract

Agriculture is a fundamental source of sustainable livelihoods in sub-Saharan Africa and millions of people in the region rely solely on small-scale farming for their food security. However, the impacts of invasive alien species (IAS) on crop production are serious, and there is no sign of this abating. Among the recent IAS that have invaded Africa in the last decade, the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been one of the most damaging. Following its first record in the Maghrebregion of Africa in 2008, T. absolutarapidly spread throughout Africa with substantial impacts on tomato production, often causing 100% yield loss. Management options adopted against T. absolutaby tomato growers in Africa have been based on the use of synthetic insecticides. While chemical insecticide applications arean important component of an integrated pest management programme, misuse and over-reliance often exacerbates the impacts of T. absolutadue to the development of resistance to commonly used active substances, increasing the fitness of the pest. This thesis sought to understand the socio-economic impacts of the spread of T. absolutain Eastern Africa and provide effective sustainable pest managementstrategies to reduce its impacts below economic thresholds.