This brochure was created in 2017 by Pete Nelson, a graduate student at North Carolina State University, who worked with the Kenya Plant Health Inspectorate Service on the Trellis Fund project, "Improving food production by adopting best pest management methods."
The tomato leaf miner, Tuta absoluta, is a moth native to South America which breads rapidly and attacks all above-ground parts of the tomato plant. Infestations of the moths can eradicate entire crops and have been reported in all tomato growing regions in Kenya.
The pests spread via seedlings, infected tomato vines, tomato fruits and used containers at markets, repacking points, and distribution centers. They feed on all parts of the plant including fruit, leaves, stems, and flowerheads. Symptoms of an infestation include abnormal shape, lesions, exit holes, dead parts of the plant, rolled leaves, leaf mines, and excrement from larvae, called frass.
Management of Tuta absoluta
Integrated Pest Management which uses multiple pest control tactics to eradicate pests is the best way to prevent the spread of tomato leaf miners.
To avoid pest spread, quarantine measures and phytosanitary field inspections of seedlings, fruits and packing containers are necessary. Host commodities intended for export must be produced in pest free facilities, and internationally bound tomatoes should be packed in insect-proof containers.
- Crop rotation with non-solanaceous crops e.g. maize and beans.
- Infested tomato fruits and other debris should be buried in deep holes instead of being dumped at farm edges, collection points or in markets.
- Keep fields weed-free as some weeds have been reported to act as alternative hosts such as Datura stramonium and indigenous vegetables like Managu.
Products that have been found to eradicate tomato leaf miners in other countries include Neem extract, Bt, Trichogramma spp., Entomopathogenic fungi and predatory bug ‘Macrolophus pygnaeus’.
Insecticide use is challenging because some tomato leaf miners have quickly developed resistance to them. However, products that have been used in other countries and are available in Kenya include Coragen, Belt, Tracer and Radiant.