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

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Salamida Daudi ◽  
Livingstone Luboobi ◽  
Moatlhodi Kgosimore ◽  
Dmitry Kuznetsov

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.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Djima Koffi ◽  
Rosina Kyerematen ◽  
Vincent Y Eziah ◽  
Yaa Oguabi Osei-Mensah ◽  
Kwame Afreh-Nuamah ◽  
...  

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.


2021 ◽  
Author(s):  
jiyingzi Wu ◽  
xianjia Li ◽  
ruiquan Hou ◽  
kunyu Zhao ◽  
yongqin Wang ◽  
...  

Abstract BACKGROUND: Since the invasion of the fall armyworm moth (Spodoptera frugiperda) in China in January 2019, damage to maize crops has gradually intensified, and chemical control has become the main control measure. This study aimed to examine methods of effective pest control while monitoring the environmental impact of pesticide use. The effectiveness of S. frugiperda pest control by foliar spraying and root irrigation of maize plants with acephate was determined, and the absorption, distribution, and dissipation of acephate and methamidophos by maize were studied.RESULTS: Field trials showed that acephate treatment at 6000 g.a.i ha-1 was the most effective for controlling S. frugiperda. Acephate and methamidophos were absorbed from the roots, transported upward, and concentrated in the leaves, particularly new leaves. The terminal residues of acephate and methamidophos in maize grains were below detectable levels at 60 days after treatment.CONCLUSIONS: The results demonstrate that acephate treatment via root irrigation can more effectively control the infestation of S. frugiperda in maize than acephate treatment via foliar spraying. The translocation and distribution of acephate and methamidophos by root irrigation were more uniform, and the holding efficiency was higher than those in foliar spraying, suggesting an extended period of control efficacy. This pest control method could be utilized to reduce pesticide residues while safely and efficiently controlling S. frugiperda infestation.


2020 ◽  
Vol 292 ◽  
pp. 106804 ◽  
Author(s):  
Hugo De Groote ◽  
Simon C. Kimenju ◽  
Bernard Munyua ◽  
Sebastian Palmas ◽  
Menale Kassie ◽  
...  

2020 ◽  
Vol 49 (3) ◽  
pp. 645-650 ◽  
Author(s):  
Djima Koffi ◽  
Komi Agboka ◽  
Delanyo Kokouvi Adenka ◽  
Michael Osae ◽  
Agbeko Kodjo Tounou ◽  
...  

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Cheng-Lung Tsai ◽  
I.-Hsuan Chu ◽  
Ming-Hsun Chou ◽  
Theeraphap Chareonviriyaphap ◽  
Ming-Yao Chiang ◽  
...  

Abstract The fall armyworm (FAW), Spodoptera frugiperda (Smith), is a major pest native to the Americas. A recent invasion of FAWs from Africa eastward to South Asia, the Indochina Peninsula, and mainland China has received much attention due to the considerable economic losses in agriculture. FAWs can rapidly colonise a new area, likely due to the wide range of host plants, good flying capability, and high egg production. Therefore, a convenient, quick, and accurate tool for FAW identification is urgently required to establish a FAW invasion management strategy. In this study, FAW-specific primers were designed to recognise FAWs on the basis of internal transcribed spacer 1 (ITS1). The results revealed the accurate FAW recognition of the three congeneric species and eight common corn lepidopteran pests, especially at their larval stage. Furthermore, species-specific primers have confirmed their efficacy by using 69 FAW specimens from Taiwan, Thailand, and the United States, with a 96% success rate, excluding 3 decayed specimens. By using the simple, reliable, and convenient FAW-specific primers, a pest management programme can be developed not only to reduce sequencing costs and experimental time from 2 days to 4 h, but eradicate the FAW as soon as it enters a new area.


Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 195 ◽  
Author(s):  
Birhanu Sisay ◽  
Josephine Simiyu ◽  
Esayas Mendesil ◽  
Paddy Likhayo ◽  
Gashawbeza Ayalew ◽  
...  

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.


2021 ◽  
Vol 22 (6) ◽  
Author(s):  
WANDA RUSSIANZI ◽  
Ruly Anwar ◽  
HERMANU TRIWIDODO

Abstract. Russianzi W, Anwar R, Triwidodo H. 2021. Biostatistics of fall armyworm Spodoptera frugiperda in maize plants in Bogor, West Java, Indonesia. Biodiversitas 22: 3463-3469. Fall Armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is an invasive species that has become important pest of maize in Indonesia since 2019. This research was aimed to study the biology and demographic statistics of FAW in maize at Bogor. Daily observations of 132 FAW individuals from egg to death were carried out as the basis for compiling biology and life table. The demographic statistics of FAW were calculated using the Jackknife approach from the basic life table data. ImagoFAW actives at night. Mating activity occurs between 06.00 pm – 04.00 am, while egg-laying activity occurs between 06.00 pm-10.00 pm. Most hatching occurs between 00.00 am - 02.00 am. FAW has 6 larvae instars and there is no difference in stage between larvae that develop into male and female, which is around 15 days. The male pupae stage was longer than the female pupae, 8.78 ± 0.12 days and 7.81 ± 0.15 days. Male and female imagoes have the same life cycle, which is about 10 days. The life cycle of FAW was 32.26 ± 0.41 days, with a preoviposition period of 2.56 ± 0.45 days. Fecundity of FAW reaches 1012.62 ± 99.12 eggs per female imago. The population of FAW in Bogor has an intrinsic growth rate of 0.154 ± 0.001 individuals/day, with gross reproduction rate of 0.154 ± 0.001 individuals per generation, and net reproduction rate of 104.781 ± 0.155 individuals per imago per generation and a generation time of 30.114 ± 0.002 days.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259749
Author(s):  
Inzamam Ul Haq ◽  
Aroosa Khurshid ◽  
Rehan Inayat ◽  
Zhang Kexin ◽  
Liu Changzhong ◽  
...  

The fall armyworm (Spodoptera frugiperda) is a major economic pest in the United States and has recently become a significant concern in African and Asian countries. Due to its increased resistance to current management strategies, including pesticides and transgenic corn, alternative management techniques have become more necessary. Currently, silicon (Si) is being used in many pest control systems due to its ability to increase plant resistance to biotic and abiotic factors and promote plant growth. The current experiments were carried out at the College of Plant Protection, Gansu Agricultural University, Lanzhou, China, to test the effect of Si on lifetable parameters and lipase activity of fall armyworm and vegetative and physiological parameters of maize plants. Two sources of Si (silicon dioxide: SiO2 and potassium silicate: K2SiO3) were applied on maize plants with two application methods (foliar application and soil drenching). The experiment results revealed that foliar applications of SiO2 and K2SiO3 significantly (P≤0.05) increased mortality percentage and developmental period and decreased larval and pupal biomass of fall armyworm. Similarly, both Si sources significantly (P≤0.05) reduced lipase activity of larvae, and fecundity of adults, whereas prolonged longevity of adults. Among plant parameters, a significant increase in fresh and dry weight of shoot, stem length, chlorophyll content, and antioxidant activity was observed with foliar applications of Si. Root fresh and dry weight was significantly (P ≤ 0.05) higher in plants treated with soil drenching of SiO2 and K2SiO3. Moreover, SiO2 performed better for all parameters as compared to K2SiO3 and control treatment. The study conclusively demonstrated a significant negative effect on various biological parameters of fall armyworm when plants were treated with Si, so it can be a promising strategy to control this pest.


2017 ◽  
Vol 16 (3) ◽  
pp. 337
Author(s):  
LETÍCIA HELLWIG ◽  
ANDERSON DIONEI GRUTZMACHER ◽  
PATRÍCIA MARQUES DOS SANTOS ◽  
CALISC DE OLIVEIRA TRECHA ◽  
LAUREN BITTENCOURT MEDINA ◽  
...  

 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.


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 512
Author(s):  
Albasini Caniço ◽  
António Mexia ◽  
Luisa Santos

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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