**1. Introduction**

The fall armyworm, *Spodoptera frugiperda* (J.E. Smith) (Lepidoptera: Noctuidae), once considered endemic to North and South America, has become an invasive pest in Africa [1]. It was detected for the first time in Sao Tome and Principe, Nigeria, Benin, and Togo in 2016 [2]. To date, the presence of *S. frugiperda* has been reported in more than 30 sub-Saharan countries [3,4]. It has been documented to feed on 353 host plants belonging to 76 plant families, mainly Poaceae, Asteraceae, and Fabaceae [5].

In the absence of proper managemen<sup>t</sup> methods, *S. frugiperda* has the potential to cause maize yield losses of 8.3 to 20.6 million metric tons per year in 12 of Africa's maize producing countries, which represents a range of 21 to 53% of the annual production of maize [4]. The value of these losses ranged from US\$ 2.48 billion and US\$ 6.19 billion [4]. In Benin, *S. frugiperda* attacks mainly maize crops [6]. Surveys carried out in 2016 by the Ministry of Agriculture, Livestock, and Fisheries of Benin revealed that over 395,000 ha of maize were damaged, resulting in a loss of 415,000 tons, or 30% of national production [6]. Therefore, it represents a threat to the country's food security and economy.

The main managemen<sup>t</sup> methods used in America against *S. frugiperda* are synthetic pesticides and genetically modified crop varieties [7]. Several studies have indicated that *S. frugiperda* is resistant to several insecticides such as pyrethroids, organophosphorus, and carbamates [8,9]. In addition, recent studies have shown resistance of *S. frugiperda* to several genetically modified varieties of maize such as MON89034, TC1507, and NK603 [10–13]. Therefore, alternative methods that reduce the application of synthetic pesticides and that use botanicals and natural enemies are recommended in Africa [1,4]. Information on farmers' knowledge and managemen<sup>t</sup> practices are essential for developing appropriate managemen<sup>t</sup> methods suited to farmers' need [14–16]. Farmers develop knowledge and managemen<sup>t</sup> practices and have their own ideas on how to solve a given problem in the practical and economical ways [17]. One of the main barriers to implementing a pest managemen<sup>t</sup> program has been shown to be the lack of information about farmers' knowledge, perceptions, and managemen<sup>t</sup> practices [18].

In the literature, two complementary approaches to the development and extension of technologies are known: conventional and participatory approaches. Some critics to conventional approach viewed it as a linear process of practical application of scientific knowledge [19], where farmers' knowledge could be overlooked in the development of technologies [20]. African farmers are well-known as innovators and experimenters [21]. The participatory approach addresses the limits of the conventional approach by considering farmers' knowledge and involving farmers in the process of development and extension of technologies [22,23].

In this study, knowledge refers to what farmers know about the biology and ecology of *S. frugiperda*. Perception refers to how farmers perceive *S. frugiperda* attacks, the damage caused by this pest, and the effectiveness of the managemen<sup>t</sup> practices they use. The identification of pests and the quantification of their damage by farmers could be quite di fferent and less accurate than that of a trained expert. Nevertheless, they provide crucial information, as farmers make decisions based on what they think is the problem [24]. Management practices used by farmers are the cumulative result of their knowledge and perceptions of the pest and depend on access to pesticides. These knowledge and perceptions are often specific to each region [25] and influenced by many socio-economic factors, for example membership in a farmer organization [26,27].

Farmers' knowledge and managemen<sup>t</sup> strategies for *S. frugiperda* have been poorly documented since its appearance in Africa. Thus far, the only study specifically focusing on farmers' knowledge of *S. frugiperda* has been carried out by Kumela et al. [28] in Kenya and Ethiopia. Their results revealed farmers' knowledge on *S. frugiperda* infestation, damage, and development stages. The managemen<sup>t</sup> practices of farmers, such as the use of synthetic pesticides, plant extracts, handpicking of larvae, and application of soil to maize whorls were also reported by the same study. However, specific information regarding natural enemies, host, and repellent plants known by farmers has not been reported, though these are important for developing sustainable pest managemen<sup>t</sup> methods. Additionally, the e ffectiveness of the di fferent managemen<sup>t</sup> practices adopted by farmers has not been addressed. The objective of the current study was to improve the understanding of the behaviour of maize farmers regarding the invasion of *S. frugiperda* in Benin. A national survey was carried out to assess farmers' knowledge of the pest, their perceptions, and managemen<sup>t</sup> practices. We hypothesize that farmers could develop e ffective managemen<sup>t</sup> strategies against *S. frugiperda* based on their knowledge and perceptions. This study will be useful to define the actions required for the sustainable managemen<sup>t</sup> of *S. frugiperda*.

#### **2. Materials and Methods**
