Fruit Fly Control

Better mango yields thanks to integrated pest management in Kenya, Tanzania and Ethiopia


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In Kenya, fruit flies often cause serious damage to mango crops. However, the flies can be controlled with an innovative combination of environmentally friendly measures (Integrated Pest Management IPM), which includes the removal of affected mangos, monitoring the fly population and using odour traps for targeted control. An important element of biological pest management is the use of bio-pesticides or natural predators such as parasitic wasps. These wasps lay their eggs on those of the mango pests. The wasp larvae eat the eggs or larvae of the fruit fly and so decimate the population. As part of this project, the wasps are being bred and released in the plantations. The farmers then learn how to establish the wasps in their own mango groves and live in harmony with them. IPM can keep the fruit-fly population in check and significantly increase the quality and quantity of the mango harvest.


Improve the food security and incomes of farmers in the project regions by strengthening and expanding the use of integrated, environmentally-friendly methods of controlling the fruit fly.


Kenia, Äthiopien und Tansania ist der Früchteanbau zunehmend eine treibende Kraft für die landwirtschaftliche Entwicklung. KleinbäuerInnen stellen dabei die wichtigste Produktionskraft dar.

Doch regelmässig werden grosse Ertragseinbussen eingefahren, welche hauptsächlich durch aus Asien eingeschleppte Fruchtfliegenarten verursacht werden. Das Weibchen der Fruchtfliege legt seine Eier in die Mango, aus welchen kurze Zeit später Maden schlüpfen und die Mangos von innen verfaulen lässt. Wissenschaftler sind zum Schluss gekommen, dass die Fruchtfliegen jährlich 40-80% Ernteverlust verursachen. Der durch die Fruchtfliegen verursachte direkte und indirekte Schaden gefährdet das Einkommen von Bauernfamilien und Mangohändlern massiv, was sich negativ auf die Nahrungssicherheit und die Lebenssituation der lokalen Bevölkerung auswirkt.


1'500 Mangoproduzentinnen und -produzenten (33% Frauen) profitieren direkt von höheren Ernteerträgen sowie einer verbesserten Qualität ihrer Produkte, was zu einer Einkommensverbesserung und Exportmöglichkeiten führt. Ausserdem sind 50 landwirtschaftliche Berater, 30 Schulungsbeauftragte und 15 Quarantine Officers (für die Qualitätskontrolle vor dem Früchteexport) direkt begünstigt. Weiter profitieren 10‘000 Personen indirekt von den besseren Mangoernten, darunter, neben 4'500 Farmangestellten und 2'500 anderen Gemüse- und Früchtebauern, 3‘000 Personen, welche im Verkauf und Export tätig sind.

Objectives of current project phase

  • Document the damage caused by fruit flies in the production of mangoes at the new project locations in Kenya and Ethiopia 
  • Introduce and adapt existing and newly developed measures for the control of fruit flies (IPM) at the new locations 
  • Wide-spread release of natural predators of the fruit flies and monitor their spread Expand the IPM measures and strengthen the mango supply chain by ensuring good agricultural practices.


The project has bred 7,500 F. arisanus and 9,000 D. longicaudata parasitic wasps: This has allowed the release of sufficient beneficial insects in the project regions. 
In addition, fruit-fly traps containing attractant have been placed in the fields. The traps are checked regularly and the number of flies caught is monitored.
In the project regions of West Embu and Machakos, 4 new locations have been established for training and demonstration purposes. They are all with easy reach of local farmers and can be used as venues for the Farmer Field Days (practical training in IPM techniques). In 2015, a total of 1,608 farmers were trained in IPM methods and provided with information material. In addition, 38 trainers from NARS (National Agricultural Research System) have been trained in IPM. They can now act as ToT (Trainer of Trainers) and spread the knowledge further. To support the expansion of IPM, a total of 1,608 starter packs including fly traps, 2 doses of attractant and information material were distributed to mango farmers at the beginning of the mango season in October. In 2015, GAP (Good Agricultural Practices) training was given to 20 people from four different farmer groups. In addition, these farmers were provided with information on the basics of marketing their fruit, focussing in particular on pricing, sales planning and general marketing.


The breeding and release of the beneficial insects requires intensive technical support and advice but once released, the insects multiply independently and require no additional care. The farmers merely have to ensure that the habitats used by the beneficial insects are not damaged by pesticides. In addition, a new facility for the production of attractants opened in March, ensuring that inexpensive, locally-produced attractants are available after the end of the project.

In addition, the project’s scientific management team is expanding its networks and forming partnerships with institutions with similar aims. This will guarantee the exchange of knowledge and experience.