Invasives Blog


CABI has published an ‘evidence note’ report on the invasive Fall Armyworm pest, showing how the caterpillar could cause maize losses costing 12 African countries up to US$6.1 billion per annum, unless control methods are urgently put in place.

Fall Armyworm: Impacts and Implications for Africa was commissioned by the UK’s Department for International Development (DFID) to review current evidence of the potential impact of Fall Armyworm in Africa. The document quantifies the likely economic effect on agricultural sectors in affected countries and regions if left unmanaged, and draws lessons for Africa from experience controlling the pest in the Americas.

Fall Armyworm in Africa has the potential to cause maize yield losses ranging from 8.3 to 20.6 million tonnes per annum, in the absence of any control methods, in just 12 of Africa’s maize-producing countries. This represents a range of 21-53 per cent of the annual production of maize averaged over a three year period in these countries. The value of these losses is estimated at between US$2,481-6,187 million.

According to the report, Fall Armyworm should be expected to spread throughout suitable habitats in mainland sub-Saharan Africa within the next few cropping seasons. Northern Africa and Madagascar are also at risk. This month, 28 countries in Africa have confirmed the pest on their territory, compared to only 12 five months earlier. A further nine countries have conducted or are presently conducting surveys, and either strongly suspect its presence or are awaiting official confirmation.

Dr Roger Day, CABI’s Sanitary and Phytosanitary (SPS) Coordinator, says, “Thanks to DFID’s support, we have been able to assemble exactly the information that many people in Africa are looking for. In the smaller-scale farming systems of central and southern America, Fall Armyworm is controlled using an integrated approach, and this is what is required in Africa.”

Immediate recommendations in the report include raising awareness on Fall Armyworm symptoms, early detection and control, and the creation and communication of a list of recommended, regulated pesticides and biopesticides to control the pest. Work must also start to assess which crop varieties can resist or tolerate Fall Armyworm. In the longer run national policies should promote lower risk control options through short term subsidies and rapid assessment and registration of biopesticides and biological control products.

Click here to download the summary of the evidence note→

Click here to download the full evidence note→

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