Experimental Manifestation : Student develops bio-pesticids to eliminate beans weevils


Reports from reliable sources can confirm that a University of Ibadan student, Mojisola Karigidi, who is also the founder of Moepelorse Bio Resources, has successfully come up with a bio-pesticide for preserving beans, pulses and other grains.

Explaining the reason why she carried out this pet research product, Karigidi said “weevils that attack beans and maize in storage can destroy as much as 40 per cent of these crops, causing huge loss to farmers and traders.

”Farmers and food crop traders who are mostly uneducated indiscriminately apply insecticides to these crops in storage to minimise or eliminate losses as much as possible.

Experimental Manifestation : Student develops bio-pesticids to eliminate beans weevils
Experimental Manifestation : Student develops bio-pesticids to eliminate beans weevils

The UI biochemistry student further revealed that even though the practice had serious health and environmental implications, she still kept on carrying out researches on medicinal plants, which prompted he with the idea to  investigate and develop a plant-based bio-pesticide to get rid of insect pests that attack food crops in storage, using lemongrass leaves particularly to wipe out beans and maize weevils,

Karigidi explained how she came up with the discovery claiming that those residing in rural areas used lemon grass locally for the treatment of mild fever, malaria and is also used in green tea products considering its medicinal properties. She also confirmed It has a long record of extensive therapeutic applications in traditional medicine in many countries across the globe.

“Apart from its medicinal properties, some people believe that growing the plant around their home can prevent the invasion of snakes and other reptiles. This belief motivated my team members and I to investigate the insecticidal ability of the plant against weevils,” she explained.

Product formulation

The researchers obtained the distillate of lemongrass by a distillation process and treated weevil-infested beans with different concentrations of the distillate. Prior to this, they reared beans weevils to breed them in large quantities for use. “The result was interesting, as we recorded the death of adult weevils within a short while. I thought of strengthening this effect by combining other botanicals like orange distillate for example, to produce a cocktail effect. The bio-pesticide formulated from this yielded 100 per cent weevil mortality within one hour of exposure,” she disclosed.

READ MORE: The Most Pressing Nutrition, Health, And Wellness Issues In Contemporary Nigeria

In another experiment, the researcher infested clean bean seeds that were without eggs with weevils and allowed the females lay eggs on the seeds. Female weevils began to lay eggs within 12 to 24 hours. The seeds containing visible weevil eggs were divided into groups and treated with different concentrations of the formulated distillate and then incubated in the dark for eight hours at room temperature to monitor adult emergence.Compared to the control group that was untreated, the treated groups showed no emergence of larva or adult weevils and no reduction in the weight of treated seeds.

The biochemist said the formulated bio-pesticide led to the mortality of both weevils and eggs, adding that further studies were done to obtain the most effective dosage.

On the product’s barrier and its commercialisation, the chief developer of the product said the present barrier to the commercialisation of the product, which has been patented under the Trademarks, Patents and Designs Registry of the Federal Ministry of Industry, Trade and Investment of the Federal Republic of Nigeria, is the cost price.

She estimated that selling price is relatively higher when produced at the small-scale level, but upon licensing to big manufacturers, production cost would be reduced when material extraction is done large-scale. That way she said, the product could be made available to farmers, traders and households at affordable and competitive rates, especially for organic products.

It is worthy of note to reckon with the fact that Mojisola Karigidi was a 2017 Aspen New Voices fellow and a 2016 fellow of the Mandela Washington fellowship programme. She was selected as a 2014 fellow of the African Women in Agricultural Research and Development (AWARD) and became an awardee of the Global Innovation through Science and Technology (GIST Tech-I) competition in 2015 based on the lemongrass pesticide. She holds a Master’s degree in Biochemistry from the University of Ibadan.

With all these experiences gathered by Karigidi, she certainly one of those youths the nation should be looking up to, as she possess potentials that could help propel the country to the world scene not just in the aspect of science, but the positive impact and inspiration she brings  to the Nigerian society.

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