Assessment of impacts of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize production in Ghana

Abstract Spodoptera frugiperda was considered an insect pest only in the Americas until its first report in African countries in 2016. In this study, farmers and agricultural officials in Ghana were interviewed on their perceptions and knowledge of the pest, on infestation and maize yield variations across years, and on management practices. Farms were inspected to determine the infestation level of 100 plants per hectare. Interviews revealed that farmers were familiar with the larval stages of this pest and noticed that the pest occurred throughout the year, but populations of S. frugiperda increased only during cropping seasons. Infestation levels reported by farmers in surveys were much lower in 2018 (30.38%) than in 2017 (80.92%). Farm inspections confirmed that infestation levels were much lower in 2018 (20.90%) than 2017 (73.70%). The belt formed by Guinea Savannah, Transitional Zone, and Semi-Deciduous Forest Agro-Ecological Zones (AEZs) recorded the highest infestations while the lowest were observed from the Sudan Savannah and Tropical Rain Forest AEZs. Insecticides were the most commonly used tactic to manage populations of this new pest. Maize yields increased across Ghana between 2013 and 2015 from 1.52 to 1.73 t/ha, decreased between 2015 and 2017 to 1.55 t/ha, and increased to 1.69 t/ha in 2018. The impact of fall armyworm injury to maize production is discussed.

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Maize Infestation of Fall Armyworm (Lepidoptera: Noctuidae) Within Agro-Ecological Zones of Togo and Ghana in West Africa 3 Yr After Its Invasion

Environmental Entomology ◽

10.1093/ee/nvaa048 ◽

2020 ◽

Vol 49 (3) ◽

pp. 645-650 ◽

Cited By ~ 2

Author(s):

Djima Koffi ◽

Komi Agboka ◽

Delanyo Kokouvi Adenka ◽

Michael Osae ◽

Agbeko Kodjo Tounou ◽

...

Keyword(s):

Spodoptera Frugiperda ◽

Fall Armyworm ◽

West African ◽

Economic Damage ◽

African Countries ◽

Ecological Zones ◽

Management Interventions ◽

Maize Plants ◽

Lepidoptera Noctuidae ◽

Agro Ecological Zones

Abstract The fall armyworm Spodoptera frugiperda (J. E. Smith) invaded several West African countries in 2016 causing severe injury to maize plants and economic damage. This study assesses variations in the occurrence of this species in different Agro-Ecological Zones (AEZs) in Togo and Ghana during the 3 yr following its discovery. The surveys were conducted on 120 farms in Togo and 94 farms in Ghana by collecting larvae from 200 maize plants per hectare. Infestation levels were 68.46% in 2016, 55.82% in 2017, and 17.76% in 2018. The number of larvae recorded per hectare and infestation levels were higher in Togo than in Ghana. The lowest number of collected larvae and infestation levels of S. frugiperda were in 2018, compared to the other 2 yr. Larvae per hectare and the infestation level varied regionally inside the two countries. The southern part of Togo (AEZ five) contained higher numbers of larvae and higher infestation levels during the 2 yr following the invasion of the pest. We concluded that infestation levels of S. frugiperda are much lower in 2018 than the two previous years and it is therefore necessary to determine the factors that affect the population dynamics of S. frugiperda in the field, which is a perquisite for developing management interventions.

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Modelling the Control of the Impact of Fall Armyworm (Spodoptera frugiperda) Infestations on Maize Production

International Journal of Differential Equations ◽

10.1155/2021/8838089 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Salamida Daudi ◽

Livingstone Luboobi ◽

Moatlhodi Kgosimore ◽

Dmitry Kuznetsov

Keyword(s):

Spodoptera Frugiperda ◽

Egg Production ◽

Bounded Solution ◽

Fall Armyworm ◽

Subsequent Increase ◽

Maize Production ◽

Severe Effect ◽

Exogenous Factors ◽

Maize Plants ◽

The Impact

In this paper, we propose and analyze a stage-structured mathematical model for modelling the control of the impact of Fall Armyworm infestations on maize production. Preliminary analysis of the model in the vegetative and reproductive stages revealed that the two systems had a unique and positively bounded solution for all time t ≥ 0 . Numerical analysis of the model in both stages under two different cases was also considered: Case 1: different number of the adult moths in the field assumed at t = 0 and Case 2: the existence of exogenous factors that lead to the immigration of adult moths in the field at time t > 0 . The results indicate that the destruction of maize biomass which is accompanied by a decrease in maize plants to an average of 160 and 142 in the vegetative and reproductive stages, respectively, was observed to be higher in Case 2 than in Case 1 due to subsequent increase in egg production and density of the caterpillars in first few (10) days after immigration. This severe effect on maize plants caused by the unprecedented number of the pests influenced the extension of the model in both stages to include controls such as pesticides and harvesting. The results further show that the pest was significantly suppressed, resulting in an increase in maize plants to an average of 467 and 443 in vegetative and reproductive stages, respectively.

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EFEITO DO AUMENTO DA DENSIDADE DE LARVAS DE Spodoptera frugiperda EM MILHO CONVENCIONAL EM CASA DE VEGETAÇÃO

Revista Brasileira de Milho e Sorgo ◽

10.18512/1980-6477/rbms.v16n3p337-350 ◽

2017 ◽

Vol 16 (3) ◽

pp. 337

Author(s):

LETÍCIA HELLWIG ◽

ANDERSON DIONEI GRUTZMACHER ◽

PATRÍCIA MARQUES DOS SANTOS ◽

CALISC DE OLIVEIRA TRECHA ◽

LAUREN BITTENCOURT MEDINA ◽

...

Keyword(s):

Zea Mays ◽

Spodoptera Frugiperda ◽

Zea Mays L ◽

Insect Pest ◽

Control Level ◽

Fall Armyworm ◽

Level Control ◽

Maize Production ◽

Artificial Infestation ◽

Lepidoptera Noctuidae

RESUMO - A produção de milho tem sofrido grandes avanços, propiciando aumento de produtividade, no entanto, esta é diretamente afetada pelo ataque de insetos desde o plantio até a sua utilização. Neste contexto, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) é considerada o principal inseto-praga. Para a cultura do milho já existem níveis de controle definidos, entretanto, mesmo utilizando os já estabelecidos, ocorrem perdas na produção. Assim, o objetivo do estudo foi reavaliar o nível de dano de S. frugiperda em milho convencional BG7060, por meio de infestação artificial com diferentes densidades populacionais de lagartas (0, 1, 3, 5, 10, 15 e 20 lagartas planta-1) em plantas no estádio fenológico V4-V8 (folhas completamente expandidas) em condições de casa de vegetação. Os resultados obtidos evidenciaram que o aumento do número de lagartas de S. frugiperda por planta afeta todas as variáveis relacionadas à produtividade, exceto a altura de planta e comprimento da espiga, propiciando uma menor produtividade. Constatou-se que o nível de controle de S. frugiperda para o híbrido BG7060 no estádios V4-V8 é 29% de plantas atacadas em uma amostragem de 100 plantas, quando ocorre uma lagarta planta-1.Palavras-chave: nível de controle, monitoramento, manejo integrado de pragas, Zea mays L. LEVEL OF DAMAGE OF FALL ARMYWORM, Spodoptera frugiperda, IN CONVENTIONAL MAIZE IN GREENHOUSE CONDITIONS ABSTRACT - The maize production has advanced considerably providing an increase in productivity, however, this is directly affected by the insect attack in all phases. In this context, the fall armyworm Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) is considered the main insect-pest. There is a control levels set for the maize production, however, using the level of control already established, production losses occur. In this sense, the purposes of the study was re-evaluate the level of damage of the S. frugiperda in conventional maize, BG7060, through artificial infestation with different populational densities (0, 1, 3, 5, 10, 15 and 20 caterpillars plant-1), of plants at V4-V8 phenological stage (fully expanded leaves) in green house conditions. The results obtained highlighted that the increase in the number of caterpillars of S. frugiperda by plant affects all variables related to productivity, except the plant height and length of the ear, providing a smaller productivity. It was found that the control level of S. frugiperda for the BG7060 maize for V4-V8 stage is 29% of attacked plants in a sample of 100 plants, when there is one caterpillar per plant.Keywords: level control, monitoring, integrated pest management, Zea mays L.

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Seasonal Dynamics of the Alien Invasive Insect Pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Manica Province, Central Mozambique

Insects ◽

10.3390/insects11080512 ◽

2020 ◽

Vol 11 (8) ◽

pp. 512

Author(s):

Albasini Caniço ◽

António Mexia ◽

Luisa Santos

Keyword(s):

Spodoptera Frugiperda ◽

Seasonal Dynamics ◽

Insect Pest ◽

Fall Armyworm ◽

Dry Season ◽

Maize Production ◽

Invasive Insect ◽

Cropping Season ◽

Lepidoptera Noctuidae ◽

Methods Of Control

The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as fall armyworm (FAW), is causing significant losses to maize production in Africa since its detection in 2016. Despite being the primary insect pest of the main food crop in the country, researchers have concentrated their efforts on methods of control, and there are no published studies on its seasonality which could assist farmers in delivering effective methods of control in periods of heavy infestations. The primary goal of this study was to assess the seasonal dynamics of FAW in maize fields. We conducted a field survey from May to August 2019 (dry season of the 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of the 2019/2020 cropping season) in 622 maize fields. In each field, 20 plants were selected in a “W” pattern and checked for the presence of FAW egg masses and/or larvae. Plants were also assessed for damage. Preliminary results show increased infestation, damages, and population density of FAW in the dry season. Our results suggest that early planting of maize in the primary cropping season may significantly reduce the infestation and damage by FAW when compared to the dry season.

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Assessment of the Host Range of Fall Armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Manica Province, Mozambique

10.20944/preprints202101.0102.v1 ◽

2021 ◽

Author(s):

Albasini Caniço ◽

António Mexia ◽

Luisa Santos

Keyword(s):

Host Range ◽

Spodoptera Frugiperda ◽

Host Plants ◽

Insect Pest ◽

Fall Armyworm ◽

Maize Production ◽

Invasive Insect ◽

Cropping Season ◽

Polyphagous Insect ◽

Lepidoptera Noctuidae

The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as Fall Armyworm (FAW), is a polyphagous insect feeding on more than 350 host plants in addition to maize in its native habitat. Due to the voracious nature of FAW, significant yield losses on maize production were reported across the African continent since its detection in 2016. Despite being a polyphagous insect, little is known about its alternative host plants in the new habitat including Mozambique. This study aimed to assess the host range of FAW in the central province of Manica, Mozambique. A field survey was conducted from May to August 2019 (dry season of 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of 2019/2020 cropping season) in maize fields and crops often mixed with maize or located in the vicinity of maize fields. A total of 1291 fields were surveyed. In each field, 20 plants were selected in a “W” pattern and checked for the presence of FAW egg masses and/or larvae. At the time of the sampling, no evidence was found suggesting that in Manica province FAW feeds in crops other than maize because out of 35 different crops surveyed, FAW was only recorded on maize. Results from this study suggest that the strain of FAW occurring in Manica province might be the one specialized in maize or the continuous availability of maize fields throughout the year is influencing the choices of the host plants of this invasive insect pest.

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Farmers’ knowledge, perception and management practices of fall armyworm (Spodoptera frugiperda Smith) in Manica province, Mozambique

NeoBiota ◽

10.3897/neobiota.68.62844 ◽

2021 ◽

Vol 68 ◽

pp. 127-143

Author(s):

Albasini Caniço ◽

António Mexia ◽

Luisa Santos

Keyword(s):

Spodoptera Frugiperda ◽

Management Practices ◽

Smallholder Farmers ◽

Insect Pest ◽

Fall Armyworm ◽

Financial Resources ◽

Management Options ◽

Maize Cultivation ◽

Lepidoptera Noctuidae ◽

Structured Questionnaire

This study aimed to gather information about farmers’ knowledge, perception and management practices of the newly introduced insect pest, the fall armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Manica province, Mozambique. A total of 200 smallholder farmers with experience in maize cultivation were surveyed using a semi-structured questionnaire. The survey was conducted between May and August 2019 in four districts: Macate, Manica, Sussundenga and Vanduzi. Most farmers were unable to morphologically identify fall armyworm (FAW) (from 93.9% in Vanduzi to 98.0% in Manica). Most farmers have experienced FAW damage in their farms (from 92% in Macate to 98.0% in Manica). Maize is mostly planted in October and November (from 44.0% in Sussundenga to 60.0% of farmers in Manica), but the highest infestation period is believed to be between November and February. With the exception of Vanduzi where 65.3% of farmers apply insecticides, most farmers in other districts do not use any method to control FAW (from 60.8% in Macate to 88.0% in Manica and Sussundenga respectively). Among those applying insecticides, from 65.0% in Manica to 75.0% in Vanduzi have confidence in the efficiency of the insecticides being used against FAW. Most farmers reported an increase in the spread of FAW. The lack of financial resources is reported as the main constraint in the fight against FAW. This study is the first of its nature in the province of Manica and provides valuable information that may support extension services and researchers when designing FAW management options for local smallholder farmers.

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Effectiveness of Push–Pull Systems to Fall Armyworm (Spodoptera frugiperda) Management in Maize Crops in Morelos, Mexico

Insects ◽

10.3390/insects12040298 ◽

2021 ◽

Vol 12 (4) ◽

pp. 298

Author(s):

Ouorou Ganni Mariel Guera ◽

Federico Castrejón-Ayala ◽

Norma Robledo ◽

Alfredo Jiménez-Pérez ◽

Georgina Sánchez-Rivera ◽

...

Keyword(s):

Spodoptera Frugiperda ◽

Insect Pest ◽

Fall Armyworm ◽

Maize Yield ◽

Morphological Development ◽

Main Method ◽

Development Of Resistance ◽

Pull Systems ◽

Complex Scenario ◽

Block Experiment

Chemical control is the main method used to combat fall armyworm in maize crops. However, its indiscriminate use usually leads to a more complex scenario characterized by loss of its effectiveness due to the development of resistance of the insect pest, emergence of secondary pests, and reduction of the populations of natural enemies. For this reason, efforts to develop strategies for agroecological pest management such as Push–Pull are increasingly growing. In this context, the present study was carried out to evaluate field effectiveness of Push–Pull systems for S. frugiperda management in maize crops in Morelos, Mexico. In a randomized block experiment, the incidence and severity of S. frugiperda, the development and yield of maize were evaluated in nine Push–Pull systems and a maize monoculture. The Push–Pull systems presented incidence/severity values lower than those of the monoculture. Morphological development and maize yield in the latter were lower than those of most Push–Pull systems. Mombasa—D. ambrosioides, Mulato II—T. erecta, Mulato II—C. juncea, Tanzania—T. erecta and Tanzania—D. ambrosioides systems presented higher yields than those of monocultures.

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First Report of Native Parasitoids of Fall Armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Mozambique

Insects ◽

10.3390/insects11090615 ◽

2020 ◽

Vol 11 (9) ◽

pp. 615

Author(s):

Albasini Caniço ◽

António Mexia ◽

Luisa Santos

Keyword(s):

Relative Abundance ◽

Spodoptera Frugiperda ◽

Smallholder Farmers ◽

Insect Pest ◽

Fall Armyworm ◽

Egg Masses ◽

Native Parasitoids ◽

Cropping Season ◽

Parasitism Rates ◽

Lepidoptera Noctuidae

The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as fall armyworm (FAW), is causing significant losses to maize production in Africa since its detection in 2016. As an emergency response, governments in several countries distributed and/or promoted massive use of synthetic insecticides among smallholder farmers to fight FAW. The inappropriate use of synthetic insecticides by non-trained and ill-equipped farmers raises environmental and health concerns. This study aimed to assess the occurrence of native parasitoids of FAW, their parasitism rates, and relative abundance in the central province of Manica, Mozambique. A field collection of FAW egg masses and larvae was conducted from May to August 2019 (dry season of the 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of 2019/2020 cropping season). A total of 101 egg masses and 1444 larvae of FAW were collected from infested fields. Five larval parasitoids were recorded, but no egg parasitism was observed. Coccygidium luteum Brullé (Hymenoptera: Braconidae) and Drino quadrizonula Thomson (Diptera: Tachinidae) were the primary parasitoids. Maximum parasitism of 23.68% and 8.86% and relative abundance of 100 and 96.3 were recorded for C. luteum and D. quadrizonula, respectively. Total parasitism by different parasitoid species was at 9.49%. Cultural practices favoring the action of these parasitoids should be advocated.

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Spread and impact of fall armyworm (Spodoptera frugiperda J.E. Smith) in maize production areas of Kenya

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2019.106804 ◽

2020 ◽

Vol 292 ◽

pp. 106804 ◽

Cited By ~ 6

Author(s):

Hugo De Groote ◽

Simon C. Kimenju ◽

Bernard Munyua ◽

Sebastian Palmas ◽

Menale Kassie ◽

...

Keyword(s):

Spodoptera Frugiperda ◽

Fall Armyworm ◽

Maize Production ◽

Production Areas

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Insecticidal activity of culture supernatants from Bacillus thuringiensis Berliner strains against Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) larvae

Anais da Sociedade Entomológica do Brasil ◽

10.1590/s0301-80591999000400010 ◽

1999 ◽

Vol 28 (4) ◽

pp. 675-685 ◽

Cited By ~ 8

Author(s):

Marliton R. Barreto ◽

Leandro L. Loguercio ◽

Fernando H. Valicente ◽

Edilson Paiva

Keyword(s):

Bacillus Thuringiensis ◽

Protein Secretion ◽

Spodoptera Frugiperda ◽

Wide Spectrum ◽

Insect Pest ◽

Polyacrylamide Gel Electrophoresis ◽

Fall Armyworm ◽

Tropical Maize ◽

Potential Applicability ◽

Culture Supernatants

Novel vegetative insecticidal proteins (Vips) identified in the supernatant of Bacillus thuringiensis (B.t.) cultures have shown to provide adequate control over a wide spectrum of economically important crop pests. To evaluate the potential applicability of these proteins against fall armyworm (Spodoptera frugiperda Smith) larvae, the most important insect pest for tropical maize, the characteristics and mortality effects of culture supernatants from five B.t. strains were investigated. Striking differences among strains were detected, not only in terms of efficiency in killing the insect, but also regarding to mortality effects of heated and non-heated supernatants, which were used to distinguish the heat-sensitive protein-derived insecticidal fraction from a thermostable one, with a non-protein nature (b-exotoxinas). The qualitative, quantitative and temporal patterns of total protein secretion in the medium (supernatant) were assessed through spectrophotometry and polyacrylamide gel electrophoresis. The strains showed remarkably distinct rates of growth and timing for protein secretion relative to cell density in culture. Moreover, the electrophoretic-banding patterns also varied in a strain-specific manner, both in denaturing and non denaturing conditions. Polypeptides displaying a molecular weight that is very close to the expected for previously identified Vip3A proteins were found for the strains with high supernatant-mortality ratios. The data suggest the feasibility and usefulness of searching for protein-derived (Vip-like) insecticidal fractions in B.t. supernatants as a mean of developing especific and efficient alternatives of biological control to be employed in integrated pest management programs of S. frugiperda in tropical maize.

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