Mango farmers use plastic bottles to fight fruit flies

A section of mango farmers in the country are using low cost plastic bottles as traps to fight the notorious fruit flies responsible for over 60 percent of fruit loss and now recording a significant drop in insect infested fruits while cutting down on pesticide use which has traditionally taken a toll on fruit quality and their pockets. The cheap baiting method comes at a time when data shows that more than four-fifths of Kenyan mango harvests are lost to the African Fruit Fly.

In a classic model where institutions are teaching fruit farmers in the farmer field schools how to assemble and mix locally available products, farmers are not just halving what they spend in pest control but now have a guaranteed year round fruit production.

For as low as Sh90 a farmer can make or access a trap that can even trap over 50,000 flies within two weeks. All one needs is a plastic bottle which is then pierced with small holes on the sides. Inside the plastic bottle a small cotton or cloth ball is soaked with female fruit fly hormones or unique liquids like sticky sugar or vinegar which acts as a lure to the male fruit fly population.

The males fly through small holes poked in the bottle and are killed by the pesticides in the lower part of the bottle. By reducing the male population in this way, farmers are now managing to control the overall fruit fly population.

Daniel Mworia a mango farmer in Tala area of Eastern Kenya knows too well what this biological method means to his half acre orchard. Having tried all conventional pesticides to no avail, with the fruit flies mutating, he gave up his mango farming. “I have been involved in mango farming for the last ten years and nowhere has the effect been devastating than last year when I lost over 80 percent of my yield to the fruit flies. Its still painful to remember,” Mworia recalled.

But this would be a blessing in disguise as an old friend returning from working in Senegal where the biological control method has been perfected would return home to find him in the process of cutting his mango trees. “He asked me what was wrong and I explained to him. It really touched him and he vowed to help me. That is how I learnt about using bottles as traps. Everything turned around from then,” he recalled.

The turnaround would come in form of Mworia getting some skeptical friends who were also into fruit farming and buffeted by the flies to try it. With the impressive results they set out on training farmers. Mworia also makes the traps for farmers who don’t have time to prepare them. The prices range from Sh90 to Sh600 based on how big they are and what liquid has been put inside. “Cereal farming has really disappointed in this area so when we realized how lucrative fruit farming is, we all delved there. So we wouldn’t take anything for granted,” added Mworia.

Fruit flies can wipe an entire orchard within days. A female fly pierces a mango and lays eggs in the ripening fruit. In two to four days the eggs hatch, releasing maggots that cause the fruit to rot and fall to the ground. Once the infested mango falls the larvae bury themselves in the soil to mature then emerge, restarting the destructive cycle.

“The idea here is, if the farmers can hit these flies before their numbers increase, they are in a safer position than waiting for the fruit to near ripening because by then nothing can stop the fertile egg-laying females from stinging fruit,” said Lucas Wanderi from Africa Alternative Pest Control Group(AAPCG), a body that trains farmers on baiting fruit flies.