The fall armyworm invasion in Africa: An overview of its economic and ecological impacts

The fall armyworm invasion in Africa: an overview of its economic and ecological impacts. 

Johnnie van den Berg* & H. Du Plessis

Unit for Environmental Sciences and Management, IPM program, North-West University, Potchefstroom, South Africa.
The invasion by fall armyworm resulted in significant economic and ecological impacts. An in initially estimate of losses in 12 African countries was between US$ 2.4–6.2 billion, and in Ghana and Zambia, the annual loss estimates for 2017 were US$177 million US$159 million respectively. Farmer’s perceptions of losses in different African countries range between 11 and 54% but actual on-farm assessments recorded much lower losses, showing that yield losses may be overestimated. To mitigate this impacts, several governments subsidized the use of synthetic insecticides, resulting in their large-scale use on maize in many countries. While insecticide application onto maize was rarely done by small holder farmers in the past, it is now increasingly being done. Due to its high invasive potential, fall armyworm also has ecological impact since it now occurs in mixed populations with other lepidopteran pests where inter-species competition may lead to changes in species complexes. The indirect impacts of this new pest in Africa included the establishment of new and progressive initiatives regarding pest management, training of farmers and general awareness of invasive species and IPM. It is also likely that the devastating damage caused by fall armyworm may influence perceptions regarding genetically modified Bt crops, and that it may affect decision making regarding this technology in future.