Invasive Insect Species Devastating Crop Production in Tanzania:  Implications on Management and Agriculture Resilience

Purpose: This study synthesised evidence on the presence, pathways, and impacts of invasive insect species (IIS) on Tanzanian agriculture. With limited consolidated data despite rich biodiversity, the research fills a critical knowledge gap. Its findings aim to inform policy, enhance biosecurity, and support the development of effective IIS management strategies suited to Tanzania’s diverse agro-ecological zones and farming systems.
Research Method: AThis study employed a systematic review methodology following PRISMA guidelines to assess the impact of invasive insect species (IIS) on Tanzania’s agriculture. A comprehensive literature search in 2024 across multiple databases retrieved 2,186 records, with 134 studies ultimately selected after screening and applying inclusion criteria based on the PICOS framework. Data were drawn from peer-reviewed studies focusing on IIS affecting crops in Tanzania. Both qualitative and quantitative data were analysed to examine invasion pathways, management strategies, yield impacts, and factors influencing the spread of IIS across Tanzanian agro-ecosystems.
Findings and Values: Seven key pathways contribute to the spread of invasive insect species (IIS) in Tanzania: international trade, maritime shipping, air travel, illegal trade, natural dispersal, and climate change. Trade and maritime activities dominate, introducing pests like Prostephanus truncatus. Weak phytosanitary systems also allow spread via air and illicit trade. Climate and natural dispersal support species like Spodoptera frugiperda and Sipha flava. A total of 27 destructive IIS were identified: 52% Hemiptera, 22% Diptera, 15% Lepidoptera, 7% Coleoptera, and 4% Trombidiformes. Pests such as Bactrocera invadens have caused export restrictions. This marks Tanzania’s first systematic review on IIS threats and management gaps.