The Efficacy of Alternative, Environmentally Friendly Plant Protection Measures for Control of Fall Armyworm, Spodoptera Frugiperda, in Maize

Abstract

The invasive fall armyworm (FAW) is threatening maize production and the livelihoods of millions of smallholder farmers in the newly invaded areas in Africa and Asia. To control this new key pest and to overcome health, environmental, and resistance problems related to the indiscriminate use of insecticides, effective and sustainable alternative pest control approaches are needed. Here, we report on field trials that tested maltodextrin, neem-based products, ash, and soil, as well as the locally produced alata samina soap, in the Upper West and Greater Accra regions, Ghana. Significant reductions of larval numbers and crop damage, together with increased yields, were mostly achieved by applying the insecticide emamectin benzoate, which was considered the positive control in this set of trials. However, high efficiency and cost–benefit ratios were also achieved with two neem-based products. Maltodextrin was only efficient at one of the two sites, with a clear dose-dependent effect, while the higher dosage was nearly as effective as emamectin benzoate. Due to its relatively high product cost, maltodextrin is generally less cost-efficient. Ash and soil, as well as alata samina soap treatments, did not efficiently reduce FAW larval numbers or crop damage at the dosages tested; thus, they also did not significantly increase maize yields.

Bio-Efficacy of Diatomaceous Earth, Household Soaps, and Neem Oil against Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae in Benin

“…To the best of our knowledge, this is the second report on the field efficacy of a household soap used as a stand-alone application against FAW in Africa and the first time Palmida soap was tested in the field as an insecticide. In contrast, Alata samina soap, an African black soap (used in Ghana and Nigeria) tested at 0.133% was not effective against FAW larvae in the field [55]. The results obtained in this study are similar to those of Amin et al [33], who successfully field-tested soap solutions at concentrations varying between 0.5 and 3% against sucking pests in cotton.…”

“…Therefore, actions need to be taken (sensitization and training) to make sure that farmers use this product adequately. The good performance of Emacot 19 EC in this study was expected given the fact that the efficacy of emamectin benzoate against caterpillars is well documented in many agricultural crops [ 55 , 81 , 82 ].…”

Managing a Transboundary Pest: The Fall Armyworm on Maize in Africa

“…Intercropping (Figure 3) practiced widely by smallholder farmers in sub-Saharan Africa has long been recognized as an efficient farming system providing improved resource utilization and increased productivity [57,58]. The practice is reported to reduce pest populations and enhance the potential of their natural enemies [59,60]. In Latin America, maize-bean intercrops reportedly reduced FAW infestation when compared to a maize monocrop [54].…”

Fall‐armyworm invasion, control practices and resistance breeding in Sub‐Saharan Africa

“…The relative effectiveness of some of these botanicals on FAW has been studied and reported (Babendreier et al., 2020; Hruska, 2019). Neem oil and neem seed and leaf powder were reported to have 70% mortality on FAW larvae (Maredia et al., 1992; Silva et al., 2015), and oil from Flooded gum ( Eucalyptus urograndis ) was effective in protecting maize (Hruska, 2019), while papaya ( Carica papaya L.) seeds ground into powder were found to be as effective as the chemical insecticide malathion {diethyl 2‐[(dimethoxyphosphorothioyl)sulfanyl]butanedioate} (Archundia et al., 2006; Figueroa‐Brito et al., 2013).…”

“…Neem oil and neem seed and leaf powder were reported to have 70% mortality on FAW larvae (Maredia et al., 1992; Silva et al., 2015), and oil from Flooded gum ( Eucalyptus urograndis ) was effective in protecting maize (Hruska, 2019), while papaya ( Carica papaya L.) seeds ground into powder were found to be as effective as the chemical insecticide malathion {diethyl 2‐[(dimethoxyphosphorothioyl)sulfanyl]butanedioate} (Archundia et al., 2006; Figueroa‐Brito et al., 2013). In Ghana, neem oil‐based products (0.17−0.33%) were found to be almost as effective as Emamectin benzoate (4′′‐Deoxy‐4′′‐epi‐methylamino‐avermectin B1) (Ema 19.2 EC) in reducing FAW damage in maize (Babendreier et al., 2020). In that study, both the low and high doses of the neem extracts had the same effect on FAW, hence lower doses were recommended for control.…”