Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae): A recent threat and future management strategy in Nepal

Abstract

Abstract. Fall Armyworm (FAW), Spodoptera frugiperda, is an invasive pest of maize including other cultivated crops such as rice, wheat, and many other vegetables. This invasive species was initially noticed in North-America and later reported in many countries of Africa in early 2016. In South Asia, this has been reported for the first time in India followed by Srilanka in 2018 and Bangladesh, China, Taiwan and Nepal in 2019. It is polyphagous in nature and damage has been reported in more than 80 plant species. The loss has to lead up to 50-80% in maize in severe situation. FAW is a distant flyer and can fly more than 100 km in a night and spread well in crop fields. As this pest is already invasive in many states of India and the likelihood of entry and spreading in Nepal is higher because of the open border between the countries and flexible government quarantine policy. The great socio-economic loss has been forecasted once this pest has received invasive status in Nepal. Recently, this crop has been confirmed by Nepal Agricultural Research Council (NARC) in Gaidakot area of Nawalpur district, Nepal and has been noticed in almost all parts of Nepal such as Sidhuli, Chitwan, Nawalparasi, Tanahun and Rupendehi districts. However, this information has not been endorsed by Nepal Plant Protection Office (NPPO), an official invasive species endorsing organization in Nepal. This species is spreading rapidly in maize growing areas and significant losses have been reported in maize crop by the farmers. The regular scouting, surveillance, and monitoring can be suggested to evaluate the pest status in the crop field. Habitat manipulation with the deployment of deterring crops ‘push’ such as desmodium (Desmodium uncinatum) and pest-attracting crop ‘pull’ such as Napier (Pennisetum purpureum) and Sudan grass (Sorghum vulgare sudanense) is suggested in a ‘push-pull strategy’, the most popular and successful method of FAW management in the maize field. Field sanitation, and conserving pest’s natural enemies are other integrated approaches. However, in a commercial maize field, a group of ‘soft’ and selective chemicals have been suggested for immediate control of this pest. This review compiled the recent informations available on FAW and is useful for farmers, researchers and policy makers to draw a roadmap for the future FAW management in Nepal.

Fall Armyworm, Spodoptera frugiperda (J.E. Smith) Management Strategies: A Synopsis

“…Several previous studies have explained about the invasion, distribution, life cycle and management of the pest (Bhusal & Bhattarai, 2019;Bhusal & Chapagain, 2020;Gahatraj et al, 2020;Gc et al, 2019). However, there are scanty literatures that explains about the efficacy of various management strategies that could been practiced for experimental research in Nepal (Bhusal & Bhattarai, 2019;Gahatraj et al, 2020). Findings from this review will be useful for the academicians, extension workers and plant protectionist to design a sustainable FAW management protocol.…”

“…FAO (2019) warned the threat and risk of invasion of FAW in Nepal since its invasion in India and believed the loss could reach 100% in maize crop. It has also been reported that there will be a greater risk of FAW if no management tactics are applied in Nepal (Bajrachharya et al, 2019;Gahatraj et al, 2020).…”

“…For the development of IPM programs for FAW, it is imperative to determine the magnitude of damage, extent of damage and effectiveness towards bio-pesticides. Several previous studies have explained about the invasion, distribution, life cycle and management of the pest (Bhusal & Bhattarai, 2019;Bhusal & Chapagain, 2020;Gahatraj et al, 2020;Gc et al, 2019). However, there are scanty literatures that explains about the efficacy of various management strategies that could been practiced for experimental research in Nepal (Bhusal & Bhattarai, 2019;Gahatraj et al, 2020).…”

Threshold of treatment of the fall armyworm (Spodoptera frugiperda) in the crop of starchy corn (Zea mays L. ssp amylaceo)

“…La infestacio n de larvas de Spodoptera frugiperda causa dan o foliar, llegando a ocasionar pe rdidas significativas en la produccio n del grano de maí z (Toma et al, 2017;Ramirez et al, 2018). Teniendo en cuenta solo el maí z, arroz, trigo (Gahatraj et al, 2020), sorgo, can a de azu car, se ha calculado que, el gusano cogollero del maí z, podrí a causar hasta 13 000 millones de do lares al an o en pe rdidas de cultivos en el Á frica subsahariana (SSÁ) (Ábrahams et al, 2017). En el a rea de distribucio n invadida por el gusano cogollero la amenaza sera duradera por la presencia de plantas hospederas y por las condiciones clima ticas favorables para la reproduccio n (Midega et al, 2018); Montezano et al, 2018).…”

Assessing New Scouting Approaches for Field Sampling of <em>Spodoptera frugiperda</em> and Its Parasitoids

“…Scouting a maize field for assessing the FAW infestation level is key to the decision of deploying curative control methods. This enables early alerts and promotes effective use of insecticides by indicating to farmers when and most importantly when not to apply insecticides based on calculations of intervention thresholds, which to the best of our knowledge are only based on expert opinion for FAW in countries of recent invasion [3][4][5] in African, Asian and Australian continents.…”