The fall armyworm attacking maize – just one of over a hundred crops the pest targets

The fall armyworm attacking maize – just one of over a hundred crops the pest targets

CABI scientists are recommending the use of more environmentally sustainable biological controls, as part of an Integrated Pest Management (IPM) strategy, to fight the fall armyworm (FAW) instead of favouring more harmful pesticides.

In a new paper published in the International Journal of Pest Management, Dr Justice Tambo led a team of researchers who suggest that policy should be geared towards educating farmers about the pest and appropriate control practices that do not over rely on synthetic products.

Dr Tambo, who used survey data from 123 farm households in Ghana and 342 in Zambia that had experienced a FAW attack on their maize plots during the 2016/2017 cropping season, said farmers need to be advised on the rational use of pesticides – where they need to be used as part of IPM – including their impacts on human health and the environment.

However, ultimately, Dr Tambo and the scientists, recommend that other control options using biological agents should be explored to fight the pest which is threatening the food security of more than 200 million people worldwide.

Dr Tambo said, “Our study showed that 51 percent of households sampled in Ghana and 49 percent in Zambia, respectively, used pesticides to control fall armyworm. However, chemical pesticides are costly and their effectiveness and impact on human health and the environment requires further research.

“Furthermore, while 39 percent and 42 percent of households, respectively, received information on FAW from neighbours and extension officers, we recommend that policy efforts should focus on widespread communication campaigns and training programmes with a stronger focus on biological controls.”

Dr Tambo added that more farmers also need to be educated and advised on other IPM techniques to managed FAW including constant weeding to remove alternative host plants; rotation and intercropping of maize with non-host plants; and uprooting and burning of infected plants to destroy larvae and pupae.

“In order to convince farmers that IPM strategies which lean more towards more sustainable biological controls are a viable option, we must demonstrate that the cost is less than the value of the yield saved,” he said.

Last year CABI scientist Dr Melanie Bateman published a paper in the Journal of Applied Entomology, ‘Assessment of potential biopesticide options for managing fall armyworm (Spodoptera frugiperda) in Africa’ – the first major study of 50 potential biological controls that could be used to fight FAW.

Current CABI research on a variety of safe non-toxic FAW management techniques are ongoing. These include the possibility of the parasitoid Telenomus remus – which was recently confirmed in Africa – could be employed to fight FAW.

Dr Marc Kenis, who is leading the research on Telenomus remus, said, “In Latin America, field releases of Telenomus remus in maize can result in 80-100 percent parasitism, providing full control of fall armyworm.

“The main challenge for a wider utilisation is to provide a product that is financially affordable for African farmers. Mass production on its natural hosts is costly but rearing systems on factitious hosts can be developed.”

Additional information

Full paper reference

Justice A. Tambo, Roger K. Day, Julien Lamontagne-Godwin, Silvia Silvestri, Patrick K. Beseh, Birgitta Oppong-Mensah, Noah A. Phiri & Mathews Matimelo (2019) ‘Tackling fall armyworm (Spodoptera frugiperda) outbreak in Africa: an analysis of farmers’ control actions’, International Journal of Pest Management, DOI: 10.1080/09670874.2019.1646942

The paper is available to view as an open access document here: