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Maize farmers destroy Fall Armyworm at 80% less cost thanks to killer wasp

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Maize farmers are using wasps to eradicate Fall Armyworms at one-fifth of the cost they previously spent on chemical pesticides.

The Fall Armyworm (FAW) is among the major pests for Kenyan farmers costing them one-third or one million tonnes of their annual maize production.

Developed by the research organisation PlantVillage, the wasp costs farmers suffering from heavy FAW attacks just Sh2,000 an acre compared to the Sh10,500 they would have paid in chemicals.

The wasp parasite has been deployed to farms in all maize-growing regions of the country and is introduced once a farmer notices the presence of the first moths and moth eggs in the maize field. Depending on the region’s climate, this happens 2-4 weeks after the plant emerges from the ground. 

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The wasp smells wherever the fall armyworm and its eggs are on the farm and specifically targets it. It then reproduces inside the eggs preventing them from ever being hatched and the fall armyworm from morphing into a caterpillar and reaching its most destructive stage.

“The wasp is much smaller than the fall armyworm. Once its eggs hatch inside the fall armyworm egg, they feed on the developing fall armyworm. They attack and destroy more than 90 per cent of FAW eggs. The wasp then emerges as an adult, mates, and goes out to look for more fresh fall armyworm eggs to kill,” explained Franklin Areba an IPM expert at Plant Village’s station in Tala.

It is released in three batches. The first release is done two to four weeks after the crop emerges then after 10-14 days, and a third release after another two weeks.

The parasite is introduced in maize fields in envelopes/cards each of which contains 10,000 wasps and is hung on maize leaves. The killer wasp is especially useful in farms where the FAW has developed resistance because of pesticide overuse. It is also used to control the diamondback moth, cotton bollworm, and pink stem borer and does not attack nor does it have any negative effects on other beneficial organisms present in the farm.

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Each card costs Sh300 and a maximum of six cards is sufficient for an acre of land that has suffered severe infestation.

The wasp can be used with herbicides such as Round-Up without being affected. For some fungicides, the farmer needs to wait two weeks before or after releasing the parasite. “We provide our farmers with a compatibility sheet which guides them on the chemical spraying programme when they have the wasps roaming in their farm,” Areba said.

Plant Village has stations in Busia, Uasin Ngishu, and Machakos Counties and can be reached on 0715034782.

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