Occurrence and distribution of Tuta absoluta (Gelechiidae) in Tanzania

Thirteen regions were surveyed for the presence and abundance of the tomato leafminer (Tuta absoluta) in Tanzania. The survey was conducted in 2015, 2016 and 2017 across selected agro-ecological regions of Tanzania. Monitoring was conducted with pheromone traps in randomly selected tomato fields. The trapped adult T. absoluta were counted once per week for four months in each season. We found that T. absoluta was present in all thirteen regions surveyed. Pest population differed significantly between regions. Regions with the highest pest populations were Iringa, Arusha and Morogoro, with trap catches of 503.8 ±17, 292.9 ± 28.9 and 239.4 ± 24.2 adults/trap/week, respectively. Regions with the lowest populations were Dodoma and Mwanza, with trap catches of 16.2 and 13.3 adults/ trap/week, respectively. The highest densities of T. absoluta and tomato damage occurred in Tanzania’s most productive tomato regions (Iringa, Arusha and Morogoro), which reflects the close relationship between this pest and its preferred host plant, tomato. These alarming findings inform farmers and the government about the distribution and intensity of the pest invasion and call for the development of effective and sustainable management strategies for T. absoluta in Tanzania.