New trap promises fruit flies rough time

Dr Sunday Ekesi, the interim Director of Research at Icipe explains a point at the launch of the fruit-fly protein bait facility in Makuyu, Murang'a. The bait attracts the flies to the spot applied, where they feed on it together with the toxicant and die. © JOSEPH KANYI | NATION MEDIA GROUP

Researchers have come up with a protein bait laced with toxicants to kill the female fruit fly, a major pest that has become a hindrance to farmers accessing the export market.

The protein bait, the researchers from International Centre of Insect Physiology and Ecology (Icipe) and Kenya Biologics Ltd, is the most effective yet economical way to eliminate the pest.

“Protein is an important nutrient in the adult fruit fly diet, therefore, specific proteins are used in bait-sprays mixed with toxicants to kill female fruit flies in an innocuous and safe way. The female flies are the pests’ producers/multipliers hence important in the insect’s survival,” said Dr Sunday Ekesi, the interim Director of Research at Icipe.

Dr Ekesi noted fruit flies are constantly attracted to waste brewers’ yeast as it contains proteins they need.

“Adult female fruit flies depend on this protein for growth, sexual maturity and egg development, hence they, and to an extent male flies, constantly seek the nutrient. The protein is harvested and used in bait-sprays mixed with a suitable toxicant providing an environmentally friendly strategy to control the flies.”

The bait attracts the flies to the spot applied, where they feed on it together with the toxicant and die soon after.

To ensure the use of the bait on farms, Icipe and Kenya Biologics Ltd, with sponsorship from numerous partners, have set up a fruit fly protein bait factory in Murang’a for production of the protein, bringing it closer to the rural smallholder farmer.

Dr Ekesi indicated that despite the high demand for the protein food bait, there were no local producers making importation unaffordable for the smallholder farmers.

Rising pressure from pests

The facility launched over a week ago is capable of producing 2,000 litres per day of the product dubbed Fruit Fly Mania.

“You may use a hand spray rather than a knapsack sprayer to apply weekly depending on the density of fruit flies on your farm,” Chris Kolenberg, the CEO, Kenya Biologics Ltd, said.

He added one should first test the flies’ presence by placing a vessel with the pheromone on the farm and constantly check for the fruit fly presence and upon verification, spray an area to attract the flies.

According to Icipe, fruit flies’ damage begin when they attack and lay their eggs in the fruit. The female fly implants its eggs into young fruits of the host plant.

The larvae or maggots develop in the flesh of untreated fruits by digging tunnels that provide opportunities for secondary infection when the larvae emerge from the fruit.

The growth of larvae accelerates maturation of the fruit, which detaches and falls to the ground. The larvae leaves the fruit and the pupae develops in the top few inches of the soil.

After it emerges from the soil, it starts looking for the nourishment it needs to reach sexual maturity, couple and lay eggs.

Many chemical pest-control products that farmers use contravene European Union’s Maximum Residue Level legislation standards for pesticides on horticultural produce, hence limiting access to export markets.

Horticulture experts have warned farmers of rising pressure from pests and insects.

Irene Mugo

The Technical Centre for Agricultural and Rural Cooperation (CTA) is a joint international institution of the African, Caribbean and Pacific (ACP) Group of States and the European Union (EU). CTA operates under the framework of the Cotonou Agreement and is funded by the EU.