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

Abstract

Spodoptera frugiperda was first reported in Africa in 2016 and has since become a serious threat to maize/cereal production on the continent. Current control of the pest relies on synthetic chemical insecticides, which can negatively impact the environment and promote the development of resistance when used indiscriminately. Therefore, great attention is being paid to the development of safer alternatives. In this study, several biorational products and a semi-synthetic insecticide were evaluated. Two household soaps (“Palmida” and “Koto”) and a detergent (“So Klin”) were first tested for their efficacy against the larvae under laboratory conditions. Then, the efficacy of the most effective soap was evaluated in field conditions, along with PlantNeem (neem oil), Dezone (diatomaceous earth), and Emacot 19 EC (emamectin benzoate), in two districts, N’Dali and Adjohoun, located, respectively, in northern and southern Benin. The soaps and the detergent were highly toxic t second-instar larvae with 24 h lethal concentrations (LC50) of 0.46%, 0.44%, and 0.37% for So Klin, Koto, and Palmida, respectively. In field conditions, the biorational insecticides produced similar or better control than Emacot 19 EC. However, the highest maize grain yields of 7387 and 5308 kg/ha were recorded, respectively, with Dezone (N’Dali) and Emacot 19 EC (Adjohoun). A cost-benefit analysis showed that, compared to an untreated control, profits increased by up to 90% with the biorational insecticides and 166% with Emacot 19 EC. Therefore, the use of Palmida soap at 0.5% concentration, neem oil at 4.5 L/ha, and Dezone at 7.5 kg/ha could provide an effective, environmentally friendly, and sustainable management of S. frugiperda in maize.

Bio- efficacy and Economics of Diatomaceous Earth against Gram Pod Borer [Helicoverpa armigera (Hubner)] in Chickpea with Combination of Beauveria bassiana, Metarhizium anisopliae and Neem Oil

“…Among all the treatments highest per cent reduction of chickpea pod borer as well as increasing the yield was recorded in T 5 (74.41%). Similar findings made by Zeni et al [10],Constanski et al [11], Aniwanou et al [12]. T 6 (73.26%) is found to be the next best treatment which is in line with the findings of Sabbour et al [13], Arooni-Hesari et al [14].…”

Invasiveness, biology, ecology, and management of the fall armyworm, Spodoptera frugiperda

“…Heavy rain forces FAW larvae out of the whorl, so the efficiency of hand picking may be increased by conducting it immediately after heavy showers. Preliminary results for soil, sand, ash, and soapy water are mixed, suggesting specific characteristics of the materials or their application are important (Babendreier et al 2020;Aniwanou et al 2021;Varma et al 2021). Ash is an unconventional pesticide that acts as a physical poison causing abrasion of insect cuticle, thus exposing pests to death through desiccation.…”

Effectiveness of Neem Oil and Jatropha Oil in Controlling Spodoptera frugiperda (J.E Smith) on Maize in the Republic of Chad

“…More specifically, Sisay et al (2019), showed in both laboratory and field trials, the efficacy of wettable powder of neem seed (applied in 5% water) against S. frugiperda. Likewise, Neem oil has also been reported by several other authors as effective in controlling S. frugiperda (Adeye et al, 2018;Duarte et al, 2019;Phambala et al, 2020;Aniwanou et al, 2021). The efficacy of Neem extracts on S. frugiperda and other insect pest species is linked to its biochemical composition that includes substances toxic to the targeted pests (Medina et al, 2003;Rakshit et al, 2008;Li et al, 2010;Insanu et al, 2013;Dono et al, 2020).…”

“…Indeed, although the maize yield increase is relatively higher with Emacot 19 EC than in the biopesticide treatments, this gain may not significantly differ from those obtained with Neem oil and Jatropha oil. Similarly, several authors have also reported yield increase of many crops treated with Neem or Jatropha oil to control insect pests (Diabaté et al, 2014a;Kammo et al, 2019;Aniwanou et al, 2021).…”