Tomato leafminer (Tuta absoluta): impacts and coping strategies for Africa.
The recently introduced tomato leafminer, Tuta absoluta, has become the most important pest constraint to tomato production in Africa. Spreading at an average 800 km/year, it is now present in 41 African countries. The socio-economic impacts of Tuta absoluta were assessed through a household survey in Kenya and Zambia in 2018, covering 400 respondents in Kenya and 426 in Zambia. We found that 97.9% of farmers in Zambia, and 99% in Kenya reported Tuta absoluta as the main problem on tomato. A majority of farmers in Zambia (57%) had lost a large proportion of their crop to Tuta absoluta, compared to 41% in Kenya. Mean seasonal production loss based on farmers' own estimates was 114,000 tonnes for Kenya and 10,700 tonnes for Zambia, equivalent to US$ 59.3, and US$ 8.7 million in economic losses respectively. Pesticides were the predominant control method for Tuta absoluta, used by 96.5% of farmers in Kenya and 97.6% of farmers in Zambia, with 6.4% using highly toxic products. However, only 27.2% and 17.2% of farmers in Kenya and Zambia, respectively, indicated the pesticide treatments were very successful. In Kenya, 73.1% of farmers applied 1-5 sprays/season, and in Zambia 29.2% applied 1-5 sprays, and 33.9% applied 6-10. The average amount spent on pesticides per household against Tuta absoluta was US$ 47.2 in Kenya, about US$ 33.7/ha, while in Zambia, this cost was US$ 42.1 per household, and US$ 9.4/ha. The average cost for a pesticide application against Tuta absoluta in Kenya was US$ 12.3, and US$ 4.2 in Zambia. The implications of these findings for sustainable management of this pest are discussed.