Blog Post

Controlling Fall Armyworm

Africa south of the Sahara continues to struggle against an invasion of Fall Armyworm. Since its first appearance in Nigeria in early 2016, the pest has spread to 28 countries. Driving the rapid spread of the pest is the region’s climate – fall armyworm tends to thrive in areas where drought is followed by heavy rains, a pattern that has intensified in recent years in many areas of Africa south of the Sahara. According to a new CABI evidence note , the pest has the potential to destroy between 21 and 53 percent of annual maize production (averaged over a three-year period) in just 12 of the region’s maize-producing countries [1] . Unless urgent control measures are put into place, CABI estimates that the damage could amount to up to USD 6.1 billion per year in these 12 countries.

According to the note, over 200 million people in the region depend on maize for food security; the crop accounts for almost 50 percent of the calories and the protein consumed in eastern and southern Africa and almost one-fifth in West Africa. Fall Armyworm will thus significantly impact food security for a large swathe of the population. The infestation could dramatically reduce yields and could increase the cost of agricultural production, impacting households’ incomes, assets, and resilience to shocks.

CABI also estimates that international trade will be impacted by the infestation. The region’s trade partners may place additional requirements or restrictions on crops being exported from countries impacted by Fall Armyworm in order to prevent the spread of the pest; this would mean increased costs for exporting countries.

According to a variety of news sources, many countries have responded to the crisis with a variety of monitoring and control measures. Ghana declared a state of emergency in May, and Ethiopia has treated 617,056 hectares of maize through a combination of chemical and traditional treatment methods. Namibia has also recently warned of the possibility of an outbreak during the 2017-2018 crop season and is working with FAO to train agricultural extension officers in proper diagnostic, monitoring, and containment measures.

The CABI report predicts that Fall Armyworm will continue to spread throughout mainland Africa south of the Sahara over the next few cropping seasons. However, the report does give a range of recommendations that farmers and governments can use to address the crisis. These include strengthening agricultural advisory services in order to increase awareness of the signs and symptoms of Fall Armyworm infestation. This can improve early detection and help farmers act before crops are destroyed.

In addition, governments and researchers need to work to make farmers aware of recommended pesticides and biopesticides that can control the pest. Governments, research organizations, and private sector actors like seed companies also need to invest in identifying and developing crop varieties, such as Bt (Bacillus thuringiensis) maize, that are more resistant to damage from the pest. While some progress has been made in identifying resistant varieties, these varieties are still not widely available.

In the longer term, the report suggests that national policies should provide for short-term subsidies to make appropriate biopesticides and biological control products more easily available and accessible to farmers. This will reduce the potentially negative environmental and health effects of the use of pesticides as a short-term solution.

By: Sara Gustafson, IFPRI


[1] Benin, Cameroon, Democratic Republic of the Congo, Ethiopia, Ghana, Malawi, Mozambique, Nigeria, Uganda, Tanzania, Zambia, and Zimbabwe.