Original Research Article

Introduction Maize (Zea mays L), is the most important crop produced in Ethiopia for Economic, livelihood, industrial, resilience to climate, and food security purposes. It is one of the country’s staple crops, grown extensively across diverse agro-ecological zones. Ethiopia ranks as the fourth-largest maize producer in Africa, following South Africa, Nigeria, and Egypt. The crop is cultivated predominantly by smallholder farmers, accounting for over 90% of production, with Oromia, Amhara, and the Southern Nations, Nationalities, and Peoples’ Region (SNNPR) being the primary maize-growing regions [1]. Maize is cultivated on approximately 2.5 million hectares of land in Ethiopia, producing an average yield of around 4 tons per hectare, significantly higher than many other African countries. This yield improvement is attributed to the adoption of improved technologies such as high-yielding maize varieties, better agronomic practices, pest management, and extension services provided by agricultural development programs [2]. However, production levels are highly variable due to factors such as rainfall dependency, pests (e.g., fall armyworm), and limited access to inputs like fertilizers and improved seeds [3] [4] The fall armyworm (Spodopterafrugiperda, Lepidoptera, Noctuidae), which is native to the Americas invaded many parts of the African continent [5] and has become a major pest of many plant species, with a strong preference for maize [6] [7]. The fall armyworm (Spodoptera frugiperda), an invasive pest, poses a severe threat to Ethiopia’s agricultural sector, particularly maize production leading to significant economic losses. FAW infestations have resulted in a national loss of approximately 0.67 million tonnes of maize, valued at $200 million, between 2017 and 2019. This pest threatens food security for millions, particularly in rural areas dependent on maize cultivation. These losses equated to the maize consumption needs of 4 million food-insecure households during this period. The fall armyworm’s impact varies by agroecology, with high infestation rates reported in mid-altitude maize-growing regions [8] [9] [10]. FAW can have many generations per year depending on environmental conditions. Adult females can live 10–21 days and lay up to 1,000 egg masses in their lifetime. Larva of fall armyworm can be identified based on inverted “Y” marking on the head area, four large dorsal spots on the second last segment in a near square arrangement, pale dorsal line, and lighter ventral and dorsal area [11] [12]. Fall armyworm feeds on whole maize plant parts and causes yield loss in severe infestation [5] [13]. In Ethiopia, FAW can cause yield losses ranging from 20% to 80%, depending on the level of infestation and management practices employed [9] [10]. [14] also reported that FAW infestation occurred on a quarter of the 2.9 million ha of land, resulting in a loss of more than 134 million tons. The pest added burden on farmers by increasing the cost of insecticide use reducing income [15] [16] and resulting in secondary fungal infection and mycotoxin levels [17] [18]. Management of the fall army appears challenging due to the availability of a diverse range of host plants throughout the year; favorable climatic conditions for its growth and development, its short life cycle, rapid multiplication, and ability to spread across large geographical areas [19] [20] [14]. Fall armyworm management strategies such as insecticides, host-plant resistance, cultural practices, crop rotation, and integrated pest management (IPM) approach are used to control FAW [21] [15] [22]. Researchers in Ethiopia emphasize integrated pest management (IPM) strategies. For instance, intercropping and climate-adapted “Push-Pull” techniques [23] have shown promise, reducing FAW infestations by over 80%. Biological control methods, including natural predators, parasitoids, and microbial agents, are gaining attention as sustainable alternatives to chemical pesticides [10] [24]. Most farmers use synthetic insecticides frequently, as the main response and effective means to control fall army infestation [7] [25] [26]. Frequent application of chemicals is unsustainable in that it negatively impacts the environment, causes a decline in biodiversity and beneficial arthropods, leads to insecticide resistance, and endangers the health of growers and consumers [27] [19].  Botanical pesticides like neem oil (Azadirachta indica) have gained attention as an eco-friendly and sustainable pest management strategy. Several studies proved the potential of plant extract as an alternative insect pest control agent [28] [29]. Research has been conducted to understand the effects of varying concentrations and application intervals of neem oil on the control of fall armyworms in maize. Neem-based bio-pesticides derived from Azadirachtaindica (from its leaves, seeds, seed oil, seed cake, and bark) are reported as well-known means for controlling fall armyworms. Neem seed and leaf extracts have great potential as a natural insecticide for the management of fall armyworms [30]. Neem affects insects by repelling and inhibiting feeding, inhibiting metamorphosis, impairing fitness and reproductive ability, and deterring egg-laying”. Oil extracted from neem has been reported to be effective in reducing fall armyworm damage on maize [31] [32] [33] [34] [35] [36]. In Ethiopia Research demonstrates that neem oil (Azadirachta indica) can effectively control fall armyworm when applied in appropriate concentrations and intervals. Higher concentrations, such as 1–3%, and shorter application intervals of 7–10 days are most effective in reducing larval populations [37]. Neem oil disrupts feeding, growth, and reproduction, aligning with integrated pest management principles. Despite challenges like labor intensity and environmental variability, neem oil enhances maize yield and reduces pest impact [38]. Surveys indicate that 97% of Ethiopian farmers are aware of FAW, with many adopting traditional control methods like handpicking caterpillars and applying wood ash. Maize growers in the South Omo zone mainly use frequently high doses of synthetic chemicals including Diazinon 60% EC for controlling severe fall army worm infestation. This practice speeds up resistance development against insecticides and increases the cost of production and health risks (Personal communication). In addition, existing methods alone are insufficient to address the widespread infestation, necessitating broader, scientifically backed interventions [9]. The use of neem products, such as neem oil derived from neem seeds has been expanded as a pesticide plant against FAW elsewhere under laboratory trial and should be evaluated under field conditions. Limited work exists on the effectiveness of neem oil in field-based evaluation in the study … Read more