Pest Control in Kenya: From Desert Locust Invasions to Integrated Pest Management Strategies

Pest management is a constant and critical challenge for Kenyan agriculture, with threats ranging from devastating desert locust swarms that can consume the equivalent of food for 35,000 people per square kilometer of swarm per day, to the persistent fall armyworm that has ravaged maize crops since its arrival in 2017. With agricultural losses from the recent desert locust invasion alone estimated at US$1.2 billion, and crop pests collectively reducing yields by 20-40% annually, Kenya's approach to pest control has profound implications for food security, farmer livelihoods, and economic development.

The Desert Locust Crisis: Kenya's Most Devastating Pest

The desert locust invasion of 2019-2021 was the worst to hit Kenya in over 70 years, exposing critical vulnerabilities in the country's pest surveillance and response systems. A single swarm covering one square kilometer can contain up to 80 million adult locusts, each consuming its own body weight in food daily. In Kenya, estimates showed 30,213 hectares of cropland and 579,786 hectares of pasture were affected, devastating pastoral and farming communities across the northern and eastern regions.

The Ministry of Agriculture established a Multi-Institutional Technical Team (MITT) on Desert Locusts drawing members from the Kenya Agricultural and Livestock Research Organization (KALRO), the Food and Agriculture Organization (FAO), the University of Nairobi, and other stakeholders. This collaborative approach proved essential for coordinating surveillance, control operations, and community engagement across the vast affected areas.

Control operations emphasized neutralizing hopper bands before they could develop into adult swarms capable of long-distance migration. Both ground control teams and aircraft spraying operations deployed insect growth regulators, biopesticides, and conventional chemical pesticides depending on the situation. The World Bank supported Kenya's response through the Kenya Locust Response Project, providing resources for surveillance equipment, control operations, and livelihood recovery for affected communities.

Integrated Desert Locust Management

Research published in the Journal of Integrated Pest Management examined farmers' perceptions of integrated desert locust management (IDLM) in Isiolo and Meru Counties. IDLM combines surveillance and early warning systems, rational use of chemicals, biological control measures, and indigenous control methods. The research found that these control methods are complementary, proving more effective when used together rather than in isolation.

Kenya has since developed a comprehensive contingency plan for desert locust management that includes enhanced surveillance networks, pre-positioned control supplies, trained response teams, and community early warning systems. Studies on factors influencing farmers' adoption of desert locust control methods reveal that group membership significantly influences adoption rates, and households engaged in commercial farming are more likely to adopt control measures to protect their investments.

Fall Armyworm: The Persistent Threat to Maize Production

The fall armyworm (Spodoptera frugiperda) arrived in Kenya in 2017 and quickly became one of the most damaging crop pests in the country. Maize, Kenya's staple food crop grown by millions of smallholder farmers, is the primary target. The CGIAR developed a strategic Integrated Pest Management plan specifically for fall armyworm affecting maize smallholders in Kenya, recognizing the need for sustainable control strategies that go beyond chemical pesticides.

IPM packages developed through research at platforms like the CIMMYT Plant Health Innovation Platform at Kiboko comprise 18 combinations of treatments including maize varieties with native genetic resistance to fall armyworm, biopesticides, biological control agents, push-pull companion cropping systems, and intercropping with bean varieties. These packages are being evaluated based on efficacy against the pest, cost-effectiveness, affordability for smallholder farmers, and potential for rapid scale-up.

The International Centre of Insect Physiology and Ecology (icipe) based in Nairobi has been at the forefront of developing new biological control arsenals for fall armyworm. Their research has identified parasitoids and natural enemies that can be deployed as part of IPM strategies, reducing dependence on synthetic pesticides while maintaining effective control.

Biopesticides: A Growing Alternative

Biopesticides represent one of the most promising developments in Kenya's pest management landscape. CABI contributed expertise to the registration of Fawligen, a biological control product formally registered by the Pest Control Products Board (PCPB) for use against fall armyworm in Kenya. Additionally, pheromone-based mating disruption technology has been registered and successfully tested among 309 farmers across three counties, providing an environmentally friendly alternative to conventional pesticides.

Despite their promise, biopesticide adoption remains low among Kenyan smallholders. Research found that only 10% of surveyed farmers in Central, Eastern, and Rift Valley provinces use biopesticides. However, 98% of non-users expressed willingness to try them as part of an IPM strategy, suggesting that the barriers are practical rather than attitudinal. Farmers who avoid biopesticides cite perceptions of ineffectiveness or slow action, limited availability, and higher costs compared to conventional pesticides.

The benefits for farmers who do adopt biopesticides and IPM approaches are significant. Farmers reported substantially reduced pesticide purchases and accompanying labor costs. Women farmers particularly benefited, recording considerable savings as they were previously compelled to hire men for spraying services when using more toxic conventional pesticides.

The Pest Control Products Board and Regulation

The PCPB serves as Kenya's regulatory authority for pesticide registration, importation, and use. All pest control products must be registered with the PCPB before they can be legally sold or used in Kenya. The Board evaluates products for efficacy, safety to humans and the environment, and quality before granting registration. This regulatory framework is essential for protecting farmers and consumers, though enforcement remains challenging given the widespread informal market for agricultural inputs.

Kenya faces a paradox in pesticide regulation: while the country has established regulatory standards, enforcement is inconsistent, particularly in rural markets where counterfeit and banned pesticides are sometimes sold. The Infonet-Biovision platform provides Kenyan farmers with information on registered biopesticides and natural pest control alternatives, helping bridge the knowledge gap that contributes to over-reliance on harmful chemicals.

Push-Pull Technology: A Kenyan Innovation

Kenya is home to one of the world's most successful IPM innovations: the push-pull technology developed by icipe and partners. This companion cropping system uses Desmodium plants between cereal crop rows to repel (push) stemborers and fall armyworm, while Napier or Brachiaria grass planted around field borders attracts (pulls) the pests away from the crop. The system simultaneously controls the parasitic Striga weed, fixes nitrogen in the soil, and provides animal fodder from the companion plants.

Push-pull has been adopted by hundreds of thousands of farmers across East Africa and has been recognized internationally as a model of sustainable intensification. The technology is particularly suited to smallholder farming systems because it requires no purchased chemical inputs, uses locally available plants, and delivers multiple benefits beyond pest control including improved soil fertility and livestock feed.

Climate Change and Emerging Pest Challenges

Climate change is reshaping Kenya's pest landscape in unpredictable ways. Rising temperatures and changing rainfall patterns alter pest lifecycles, expand the geographical range of existing pests, and create conditions for new pest invasions. The desert locust invasion was linked to unusual cyclone activity in the Indian Ocean that created favorable breeding conditions in the Horn of Africa, highlighting how climate variability can trigger pest emergencies.

Adapting pest management strategies to a changing climate requires investment in surveillance systems that can detect emerging threats early, flexible response mechanisms, and research into pest biology under changing conditions. Kenya's experience with the desert locust crisis demonstrated both the devastating potential of climate-linked pest events and the value of coordinated, science-based response systems.

The Future of Pest Management in Kenya

Kenya's pest management future lies in scaling up integrated approaches that combine biological control, resistant crop varieties, cultural practices, and judicious chemical use. The country's strong research base, including icipe, KALRO, and university programs, provides a foundation for developing locally appropriate solutions. Expanding farmer access to biopesticides, strengthening the push-pull technology network, and building climate-resilient surveillance systems are all priorities that will determine whether Kenya can protect its agricultural productivity against evolving pest threats.