John Ndung’u’s farm, located in Murang’a County, hosts tens of mango trees. “I have commenced preparing the trees for the next season,” says Ndung’u, who has 180 trees. Each of the trees has two or three yellow and white plastic containers hanging on one of the stems. These are traps for curbing fruit flies in particular.
“Fruit flies are very destructive and they are the worst enemies of mangoes. They don’t allow them to mature,” explains the farmer, who started growing the fruits in 1998 on half an acre.
Apart from mangoes, fruit flies also attack oranges and other citrus fruits and pumpkins. Normally, the insects enter the fruits and lay eggs inside, which hatch and make the pests difficult to control. The fruits then start ripening while still young, according to Ndung’u, and then fall from the tree. Affected mangoes normally have a bitter taste and produce some sticky sap, making them unfit for consumption.
But with his traps, Ndung’u has managed to curb the pest. “I usually place the pheromone traps on trees when flowering begins. They contain chemicals to attract the male flies and kill them, thus preventing mating.” Ndung’u says that an acre offers him 24,000 mango fruits per season.
Simon Nduati, an agronomist in Murang’a, says each trap has two holes on the lid. “The traps are hooked on the mango tree, two on each. Upon smelling the chemicals, the male fruit flies enter the pheromone trap and end up dying inside,” he explains.
Nation.co.ke explains that, on average, Nduati says each container traps about 1,000 fruit flies per day, noting that with the technique, farmers are spending farm much less money than when using pesticides.