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

AbstractMaize (Zea mays L.) is one of the most important and widely cultivated crops in Argentina. Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a common maize pest capable of causing significant yield losses and is most destructive in late-planted maize in subtropical regions, going through five to six generations per growing season. The Bacillus thuringiensis (Bt) trait Herculex I Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred (HX I, event DAS-Ø15Ø7-1), expressing Cry1F protein, was launched in the 2005–2006 season in Argentina and was widely adopted because of the high level of efficacy against S. frugiperda, as well as other pests such as Diatraea saccharalis (J.C. Fabricius). However, increased late-season plantings, limited adoption of refuge, and properties of S. frugiperda biology (high number of generations and migratory behavior) have led to high S. frugiperda exposure to Cry1F and resistance selection pressure. Field efficacy monitoring has been conducted throughout the main maize production areas in Argentina from 2009 to 2016. Laboratory monitoring has been conducted throughout the same areas from 2010 to 2015. Here, we describe changes in field efficacy of HX I and the results of laboratory-based susceptibility monitoring conducted using purified Cry1F protein. Increases in larval survival and crop damage were evident throughout the 2012–2016 period and spanned the majority of maize production areas in Argentina. Over the same period, random larval collections showed increasing survivorship on diet containing purified Cry1F protein. These field and laboratory studies confirmed that resistance to Cry1F has developed and is now widely distributed in S. frugiperda populations in Argentina.

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Fall Armyworm, Spodoptera frugiperda Infestations in East Africa: Assessment of Damage and Parasitism

Insects ◽

10.3390/insects10070195 ◽

2019 ◽

Vol 10 (7) ◽

pp. 195 ◽

Cited By ~ 14

Author(s):

Birhanu Sisay ◽

Josephine Simiyu ◽

Esayas Mendesil ◽

Paddy Likhayo ◽

Gashawbeza Ayalew ◽

...

Keyword(s):

Biological Control ◽

East Africa ◽

Spodoptera Frugiperda ◽

Fall Armyworm ◽

Egg Parasitoid ◽

Leaf Damage ◽

Parasitism Rate ◽

Maize Production ◽

Larval Parasitoid ◽

Percent Parasitism

The fall armyworm (FAW), Spodoptera frugiperda, threatens maize production in Africa. A survey was conducted to determine the distribution of FAW and its natural enemies and damage severity in Ethiopia, Kenya and Tanzania in 2017 and 2018. A total of 287 smallholder maize farms (holding smaller than 2 hectares of land) were randomly selected and surveyed. FAW is widely distributed in the three countries and the percent of infested maize fields ranged from 33% to 100% in Ethiopia, 93% to 100% in Tanzania and 100% in Kenya in 2017, whereas they ranged from 80% to 100% and 82.2% to 100% in Ethiopia and Kenya, respectively, in 2018. The percent of FAW infestation of plants in the surveyed fields ranged from 5% to 100%. In 2017, the leaf damage score of the average of the fields ranged from 1.8 to 7 (9 = highest level of damage), while 2018, it ranged from 1.9 to 6.8. In 2017, five different species of parasitoids were recovered from FAW eggs and larvae. Cotesia icipe (Hymenoptera: Braconidae) was the main parasitoid recorded in Ethiopia, with a percent parasitism rate of 37.6%. Chelonus curvimaculatus Cameron (Hymenoptera: Braconidae) was the only egg-larval parasitoid recorded in Kenya and had a 4.8% parasitism rate. In 2018, six species of egg and larval parasitoids were recovered with C. icipe being the dominant larval parasitoid, with percentage parasitism ranging from 16% to 42% in the three surveyed countries. In Kenya, Telenomus remus (Hymenoptera: Scelionidae) was the dominant egg parasitoid, causing up to 69.3% egg parasitism as compared to only 4% by C. curvimaculatus. Although FAW has rapidly spread throughout these three countries, we were encouraged to see a reasonable level of biological control in place. Augmentative biological control can be implemented to suppress FAW in East Africa.

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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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Predatory Ability of Harmonia axyridis (Coleoptera: Coccinellidae) and Orius sauteri (Hemiptera: Anthocoridae) for Suppression of Fall Armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

Insects ◽

10.3390/insects12121063 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1063

Author(s):

Ning Di ◽

Kai Zhang ◽

Qingxuan Xu ◽

Fan Zhang ◽

James D. Harwood ◽

...

Keyword(s):

Biological Control ◽

Functional Response ◽

Natural Enemies ◽

Spodoptera Frugiperda ◽

Harmonia Axyridis ◽

Fall Armyworm ◽

Handling Time ◽

Invasive Pest ◽

Maize Production ◽

First Instar

The lepidopteran pest, Spodoptera frugiperda (JE Smith), spread rapidly after its first detection in China and has caused significant yield loss to maize production in the southwestern part of the country. Although natural enemies of S. frugiperda are present in the field, biological control using naturally distributed predators is ineffective because their underlying populations are too low. To enhance our understanding of the potential role of natural enemies in regulating this invasive pest, functional response experiments were conducted to quantify the response of two predators, Orius sauteri (Poppius) (Hemiptera: Anthocoridae) and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in terms of consumption of S. frugiperda. Experimental results revealed that the predatory effects of nymphs of O. sauteri and H. axyridis on the eggs and larvae of S. frugiperda fitted Holling’s Type II functional response model. Importantly, the theoretical maximum number of prey consumed per day (Na-max), the instantaneous attack rate (a′) and the handling time (Th) of O. sauteri nymphs on S. frugiperda eggs were 15.19, 0.7444 and 0.049 d, respectively; and the parameters on first instar larvae of S. frugiperda were 700.24, 0.5602 and 0.0008 d, respectively. These data contrast to those of H. axyridis, where the Na-max, a′ and Th of adults on eggs of S. frugiperda were 130.73, 1.1112 and 0.085 d, respectively, and on the first instar larvae of S. frugiperda were 1401.1, 0.8407 and 0.0006 d, respectively. These results revealed that H. axyridis is a highly voracious predator of the eggs and young larvae of S. frugiperda and O. sauteri could also be used as biocontrol agent of this pest. Our work provides a theoretical framework for the application of natural enemies to control S. frugiperda in the field. Further research is required to strategize conservation biological control approaches in the field to increase populations of these predators and enhance the suppression of S. frugiperda.

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

Journal of Integrated Pest Management ◽

10.1093/jipm/pmaa015 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Djima Koffi ◽

Rosina Kyerematen ◽

Vincent Y Eziah ◽

Yaa Oguabi Osei-Mensah ◽

Kwame Afreh-Nuamah ◽

...

Keyword(s):

Spodoptera Frugiperda ◽

Management Practices ◽

Deciduous Forest ◽

Insect Pest ◽

Fall Armyworm ◽

Transitional Zone ◽

African Countries ◽

Maize Production ◽

Ecological Zones ◽

The Impact

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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Outbreaks of a new invasive pest, the fall armyworm (Spodoptera frugiperda) in South Sumatra, Indonesia

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/912/1/012019 ◽

2021 ◽

Vol 912 (1) ◽

pp. 012019

Author(s):

S Herlinda ◽

M E Sinaga ◽

F Ihsan ◽

F Fawwazi ◽

S Suwandi ◽

...

Keyword(s):

Population Density ◽

Plant Species ◽

Spodoptera Frugiperda ◽

Fall Armyworm ◽

Invasive Pest ◽

The South ◽

Maize Production ◽

The Mean ◽

Larvae Density

Abstract Spodoptera frugiperda is polyphagous besides attacking maize, it can attack other plant species from various families. Information about the attack and population of S. frugiperda in various maize production centers in Indonesia is still limited. This study aimed to find out the population and attack of S. frugiperda in South Sumatra. Surveys were carried out from the lowlands to the highlands of South Sumatra, such as Palembang City, Pagar Alam City, Lahat City, Ogan Ilir District, Prabumulih City, Muara Enim District, Banyuasin District. The mean percentage severity of S. frugiperda in South Sumatra reached 34.75%, and its percentage of mean incidence reached 78%. The highest larvae density was found in Pagaralam City with an average of 0.29 larvae/100 plants, while the lowest was found in Muara Enim District (0.08 larvae/100 plants). The population density of larvae began to occur at the age of 3 to 5 weeks, after that the larvae were not found in maize fields. We found that outbreaks of S. frugiperda have occured in the South Sumatra.

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Baseline Susceptibility of Spodoptera frugiperda Populations Collected in India towards Different Chemical Classes of Insecticides

Insects ◽

10.3390/insects12080758 ◽

2021 ◽

Vol 12 (8) ◽

pp. 758

Author(s):

Mahesh Kulye ◽

Sonja Mehlhorn ◽

Debora Boaventura ◽

Nigel Godley ◽

Sreedevi Kodikoppalu Venkatesh ◽

...

Keyword(s):

Spodoptera Frugiperda ◽

Management Strategies ◽

Resistance Management ◽

Fall Armyworm ◽

Reference Population ◽

Maize Production ◽

Pyrethroid Insecticides ◽

Eastern Hemisphere ◽

Major Pest ◽

Moderate Resistance

Fall armyworm (FAW), Spodoptera frugiperda, is a major pest of maize in the Americas and recently invaded the Eastern hemisphere. It was first detected in India in 2018 and is considered a major threat to maize production. FAW control largely relies on the application of chemical insecticides and transgenic crops expressing Bacillus thuringiensis insecticidal proteins. Assessing FAW resistance and insecticide susceptibility is a cornerstone to develop sustainable resistance management strategies. In this study, we conducted more than 400 bioassays to assess the efficacy of nine insecticides from seven mode-of-action classes against 47 FAW populations collected in 2019 and 2020 across various geographical areas in India. The resistance status of the field-collected populations was compared to an Indian population sampled in 2018, and an insecticide susceptible reference population collected in 2005 in Brazil. Low to moderate resistance levels were observed for thiodicarb, chlorpyriphos, deltamethrin, chlorantraniliprole and flubendiamide in several populations (including the reference population collected in 2018). The highest resistance ratios were observed for deltamethrin which likely compromises recommended label rates for pyrethroid insecticides in general. Our data provide a useful baseline for future FAW resistance monitoring initiatives and highlight the need to implement insecticide resistance management strategies.

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