Fall armyworm from a maize multi-peril pest risk perspective

Abstract

We assembled 3,175 geo-tagged occurrences of fall armyworm worldwide and used that data in conjunction with information about the physiological requirements of the pest to spatially assess its global climate suitability. Our analysis indicates that almost the entire African maize crop is grown in areas with climates that support seasonal infestations of the insect, while almost 92% of the maize area supports year-round growth of the pest. In contrast, rich-country maize production largely occurs in temperate areas where only 2.3% of the area may allow the pest to survive year-round, although still subject to worrisome seasonal risks. This means the African maize crop is especially susceptible to damaging infestation from fall armyworm, on par with the risk exposure to this pest faced by maize producers throughout Latin America. We show that the maize grown in Africa is also especially vulnerable to infestations from a host of other crop pests. Our multi-peril pest risk study reveals that over 95% of the African maize area deemed climate suitable for fall armyworm, can also support year-round survival of at least three or more pests. The spatial concurrence of climatically suitable locations for these pests raises the production risk for farmers well above the risks posed from fall armyworm alone. Starkly, over half (52.5%) of the African maize area deemed suitable for fall armyworm is also at risk from a further nine pests, while over a third (38.1%) of the area is susceptible to an additional 10 pests. This constitutes an exceptionally risky production environment for African maize producers, with substantive and complex implications for developing and implementing crop breeding, biological, chemical and other crop management strategies to help mitigate these multi-peril risks.

Migration risk of fall armyworm (Spodoptera frugiperda) from North Africa to Southern Europe

“…Our annual suitable distribution extends further south in South America and Africa and further north in India. This is consistent with the research results of Senay et al (2022), who pointed out that countries such as Angola, Botswana, Namibia, and some areas along the eastern coast of South Africa, as well as highlatitude areas in India, can support the year-round survival of FAW.…”

Hybrid breeding for fall armyworm resistance: Combining ability and hybrid prediction

“…In the absence of a sustainable FAW control strategy, maize production in SSA is projected to be exceptionally risky (Haftay, 2020;Overton et al, 2021). This is because climatic conditions in most maize-growing agro-ecology support the multi-generational establishment of voracious and polyphagous FAW pest (Senay et al, 2022).…”

“…In the absence of a sustainable FAW control strategy, maize production in SSA is projected to be exceptionally risky (Haftay, 2020; Overton et al, 2021). This is because climatic conditions in most maize‐growing agro‐ecology support the multi‐generational establishment of voracious and polyphagous FAW pest (Senay et al, 2022). Effective deployment of HPR to mitigate yield and economic losses emanating from the wide‐scale destruction of the maize crop by the FAW insect pest, therefore, requires an in‐depth understanding of the genetic differences for resistance to FD and other important traits like GY.…”

“…This is partly because FAW is an invasive pest, and the focus of insect resistance breeding was on existing lepidopteran pests such as stem borers. Development, deployment and improved FAW‐resistant hybrids are the pre‐requisites for a better farmer harvest, trade and financial surplus in the context of a devastating pest that is likely to establish itself as a multi‐generation pest of economic importance in SSA (Senay et al, 2022). In addition to screening large sets of diverse maize germplasm under artificial FAW infestation to discover resistance lines from multiple sources (Soujanya et al, 2022), determination of their combining abilities of these inbreds with a view of quantifying their genetic effects controlling the inheritance of the resistance is also crucial (Fasahat et al, 2016).…”

Validating Indigenous Farmers’ Practice in the Management of the Fall Armyworm Spodoptera frugiperda (J. E. Smith) in Maize Cropping Systems in Africa

“…FAW is also reproductively very efficient in tropical areas, where the warmer temperatures allow for more generations to be propagated per year, compared with temperate areas that may have one up to two in a year [6,7]. Therefore, seasonal infestations of maize crops have been reported in most African countries because about 92% of the area under maize farming in Africa supports the conditions for year-round survival and reproduction of FAW [8].…”