Concentration–Mortality Response of Mexican Populations Fall Armyworm (Lepidoptera: Noctuidae) to Commercial Formulations of Bacillus Thuringiensis

2021 ◽  
Vol 56 (1) ◽  
pp. 70-83
Author(s):  
María del Carmen Lara-Becerra ◽  
Manuel Alejandro Tejeda-Reyes ◽  
Ángel Lagunes-Tejeda ◽  
Gonzalo Silva-Aguayo ◽  
J. Concepción Rodríguez-Maciel
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Frugiperda ◽  
Zea Mays L ◽  
Fall Armyworm ◽  
Mortality Response ◽  
Important Pest ◽  
Median Lethal Concentrations ◽  
Lepidoptera Noctuidae ◽  
Laboratory Bioassays ◽  
Mexican Populations

Abstract The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is the most economically important pest of maize (Zea mays L.) grown in Mexico. In order to identify biologically based management tactics for this pest, we determined the concentration–mortality response of 16 S. frugiperda populations collected in Mexico to two commercial formulations of Bacillus thuringiensis Berliner (Bt) (XenTari® [Bt subsp. aizawai] and DiPel® [Bt subsp. kurstaki]; Valent de México SA De CV, Jalisco, México). Laboratory bioassays established median lethal concentrations (LC50s) for each Bt formulation × population combination. We also determined mean larval weight 7 d after exposure and the number of larvae that reached the third instar of development. The populations were susceptible to both Bt formulations but they were, overall, more susceptible to Bt subsp. aizawai (XenTari) than to Bt subsp. kurstaki (DiPel). These results can serve as a reference to detect changes in S. frugiperda response to these Bt commercial products over time.

Bioassay for Screening Plant Accessions for Resistance to Fall Armyworm (Lepidoptera: Noctuidae) Using Artificial Diets

1991 ◽  
Vol 26 (3) ◽  
pp. 367-374 ◽  
Author(s):  
M. M. Diawara ◽  
B. R. Wiseman ◽  
D. J. Isenhour
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Plant Introductions ◽  
Resistance To Insects ◽  
Pinto Bean ◽  
Low Levels ◽  
Sorghum Genotypes ◽  
Lepidoptera Noctuidae ◽  
Sorghum Bicolor L ◽  
Laboratory Bioassays

Laboratory bioassays demonstrated that formulation of artificial insect diet influenced the expression of antibiosis to fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), in grain sorghum, Sorghum bicolor (L.) Moench. Larvae of FAW were reared on a diet formulated with pinto bean and a diet formulated with no pinto bean, both supplemented with dried milk stage florets of resistant and susceptible sorghum genotypes. The sorghum lines showed a significantly higher antibiosis to FAW when mixed in the diet formulated with no pinto bean than when mixed in the diet containing the bean. Larvae that were fed the no-bean diet supplemented with resistant sorghum genotypes weighed one-half to one-third less, required longer to pupate, and resulted in lighter pupae than larvae reared on mixtures containing the bean. The results obtained when the larvae were reared on the bean diet were significantly correlated (P = 0.0001, r > 0.80, n = 18) with those recorded when the no-bean diet was used for the FAW variables measured. Because a higher expression of antibiosis is obtained with the no-bean diet, this formulation should be recommended for bioassays designed to study lines with low levels of resistance to insects or to screen plant introductions in which the level of resistance is not known.

scholarly journals Evaluation of the Bio-Insecticidal Effect of Ricinus communis (Malpighiales: Euphorbiaceae) on the Larvae of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

2021 ◽  
Vol 9 (4) ◽  
pp. 118-123
Author(s):  
Cheikh Atab Diédhiou ◽  
Keyword(s):  
Mortality Rate ◽  
Spodoptera Frugiperda ◽  
Control Method ◽  
Ricinus Communis ◽  
Fall Armyworm ◽  
Control Solution ◽  
Insecticidal Effect ◽  
Emergence Of Resistance ◽  
Lepidoptera Noctuidae ◽  
Laboratory Bioassays

Since chemical insecticides favor the emergence of resistance and have disastrous consequences for the environment, we became interested in an alternative control method against Spodoptera frugiperda, more respectful for the environment. We therefore evaluated the effectiveness of the bio-insecticidal effects of plants extracts and oil of castor against the fall armyworm in the laboratory. The laboratory bioassays consisted of evaluating the toxicity of the castor plants extracts and oil by contact and ingestion on fourth instar larvae of Spodoptera frugiperda using a leaf dipping method. It emerges from this study that the mortality of the larvae treated with the bio-insecticide and the control solution varies significantly and that the mortality rate was 100% for dose 1; 85% for dose 2 and 70% for dose 3. The mortality rate for the control solution is 10%. These results testify to the good larvicidal activity of the organic insecticide based on oil, leaves and unripe seeds of castor bean on the fall armyworm.

scholarly journals Biorational management of maize fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) using Bacillus thuringiensis (Berliner) enriched with chemical additives

2021 ◽  
Vol 13 (4) ◽  
pp. 1231-1237
Author(s):  
M. Priyanka ◽  
P. Yasodha ◽  
C.Gailce Leo Justin ◽  
J. Ejilane ◽  
Venugopal Rajanbabu
Keyword(s):  
Bacillus Thuringiensis ◽  
Boric Acid ◽  
Sodium Nitrate ◽  
Spodoptera Frugiperda ◽  
Seedling Emergence ◽  
Fall Armyworm ◽  
Invasive Pest ◽  
Chemical Additives ◽  
Stage Of Development ◽  
Lepidoptera Noctuidae

An invasive pest, fall armyworm, Spodoptera frugiperda (J.E.Smith) (Lepidoptera: Noctuidae) attacks maize at every stage of development, from seedling emergence up to cob formation. Early instar larvae were seen mostly on leaves of maize with characteristics pin or shot hole symptoms. Later instar larvae were confined to deep whorls, leaving typically ragged like appearance and fed on the reproductive stage of the crop especially tassels and developing cobs resulting in quality and quantity loss of maize produce. The effect of commercially available Bacillus thuringiensis subsp. kurstaki product, Dipel® against the second instar larvae of Fall Armyworm (FAW )was not promising under laboratory conditions. Hence, an effort was made to add an adjuvant along with B. thuringiensis to increase the virulence of commercially available B. thuringiensis.The Laboratory bioassays with B. thuringiensis and seven chemical additives ( T1- Bt + Boric acid, T2- Bt + Zinc oxide, T3- Bt + Sodium nitrate, T4- Bt + Peptone, T5- Bt + Urea, T6- Bt + EDTA, T7- Bt + Citric acid & T8-  Bt alone T9- Control) were tested against second instar larvae of Spodoptera frugiperda larvae. The results showed that B. thuringiensis plus sodium nitrate (T3) promoted maximum mortality 82.2 per cent with a minimum LC50 value of 54.620 mg/l. Sodium nitrate boosted B. thuringiensis activity at a concentration of 0.05 per cent by 2.128-fold than B. thuringiensis alone. Overall, sodium nitrate improved the efficacy of B. thuringiensis spray at the maximum level followed by boric acid, urea, EDTA and peptone.

scholarly journals Bacillus thuringiensisCry1Da_7 and Cry1B.868 Protein Interactions with Novel Receptors Allow Control of Resistant Fall Armyworms,Spodoptera frugiperda(J.E. Smith)

2019 ◽  
Vol 85 (16) ◽  
Author(s):  
Yanfei Wang ◽  
Jinling Wang ◽  
Xiaoran Fu ◽  
Jeffrey R. Nageotte ◽  
Jennifer Silverman ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Protein Interactions ◽  
Spodoptera Frugiperda ◽  
Insect Cells ◽  
Fall Armyworm ◽  
Insecticidal Protein ◽  
Row Crops ◽  
Content Type ◽  
Resistance Risk ◽  
Important Pest

ABSTRACTTwo new modifiedBacillus thuringiensis(Bt) proteins, Cry1Da_7 and Cry1B.868, with activity against fall armyworms (FAW),Spodoptera frugiperda(J.E. Smith), were evaluated for their potential to bind new insect receptors compared to proteins currently deployed as plant-incorporated protectants (PIPs) in row crops. Results from resistant insect bioassays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that receptor utilizations of the newly modified Cry1Da_7 and Cry1B.868 proteins are distinct from each other and from those of commercially availableBtproteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Accordingly, these two proteins target different insect proteins in FAW midgut cells and when pyramided together should provide durability in the field against this economically important pest.IMPORTANCEThere is increased concern with the development of resistance to insecticidal proteins currently expressed in crop plants, especially against high-resistance-risk pests such as fall armyworm (FAW),Spodoptera frugiperda, a maize pest that already has developed resistance toBacillus thuringiensis(Bt) proteins such as Cry1F. Lepidopteran-specific proteins that bind new insect receptors will be critical in managing current Cry1F-resistant FAW and delaying future resistance development. Results from resistant insect assays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that target receptors of the Cry1Da_7 and Cry1B.868 proteins are different from each other and from those of commercially availableBtproteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Therefore, pyramiding these two new proteins in maize will provide durable control of this economically important pest in production agriculture.

Spore-Toxin Interactions and Sublethal Effects of Bacillus thuringiensis in Spodoptera frugiperda and Pseudoplusia includens (Lepidoptera: Noctuidae)

1996 ◽  
Vol 31 (1) ◽  
pp. 52-62 ◽  
Author(s):  
F. F. R. Nyouki ◽  
J. R. Fuxa ◽  
A. R. Richter
Keyword(s):  
Bacillus Thuringiensis ◽  
Life Span ◽  
Spodoptera Frugiperda ◽  
Sublethal Effects ◽  
Synergistic Effects ◽  
Pseudoplusia Includens ◽  
Pupal Weight ◽  
Median Lethal Concentrations ◽  
Lepidoptera Noctuidae ◽  
Sublethal Concentrations

Interactions between the spores and δ-endotoxins of Bacillus thuringiensis Berliner were tested in a low-susceptibility insect, Spodoptera frugiperda (J. E. Smith). The spores (formulation MYD™) and one δ-endotoxin (formulation MVP™) had additive effects on mortality at a MVP™ dose of 117,500 μg/g of diet (P < 0.01) and synergistic effects at a MVP™ dose of 235,000 μg/g diet (P < 0.01). The spores and another δ-endotoxin (formulation MYX™) were antagonistic at a MYX™ dose of 117,500 μg/g diet (P < 0.01) and additive at a MYX™ dose of 235,000 μg/g diet (P < 0.01). The two δ-endotoxin formulations were additive with one another (P < 0.01). Sublethal concentrations of MVP™ fed to larvae retarded the development of larvae and pupae for 5 d (P < 0.01) and 1.2 d (P < 0.01), respectively, and decreased pupal weight by 48 mg (P < 0.01). The spore formulation did not affect (P > 0.05) pupal weight or the life span of larvae or pupae. Median lethal concentrations of MVP™ and MYX™ were 6,904 and 7,561 × greater, respectively, in S. frugiperda than in Pseudoplusia includens (Walker). In P. includens, sublethal concentrations of MVP™, MYX™, and Dipel™ fed to larvae significantly (P < 0.05) reduced pupal weight and increased pupal life span compared to control insects. MVP™ and Dipel™ increased larval life span significantly (P < 0.05), but MYD™ did not.

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

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.

Evaluation of Corn Hybrids Expressing CrylF (Herculex® I Insect Protection) Against Fall Armyworm (Lepidoptera: Noctuidae) in the Southern United States

2008 ◽  
Vol 43 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Melissa Willrich Siebert ◽  
Kelly V. Tindall ◽  
B. Rogers Leonard ◽  
John W. Van Duyn ◽  
Jonathan M. Babcock
Keyword(s):  
Spodoptera Frugiperda ◽  
Zea Mays L ◽  
Larval Mortality ◽  
Fall Armyworm ◽  
Laboratory Studies ◽  
Insecticidal Crystal Protein ◽  
Corn Hybrids ◽  
Field Corn ◽  
Field Plots ◽  
Lepidoptera Noctuidae

Efficacy of two insect-resistant corn hybrids expressing the Cry1 F insecticidal crystal protein of Bacillus thuringiensis var. aizawai Berliner (transformation event TC1507) was evaluated against fall armyworm, Spodoptera frugiperda (J.E. Smith), in three southern U.S. locations. Larval susceptibility was evaluated on CrylF and nonBt field corn, Zea mays L., plants (V3–V12 and R1–R2 stages) in field plots and laboratory studies. Leaf-feeding injury was significantly less and plant height was significantly greater for hybrids containing Cry1 F as compared with nonBt corn hybrids when exposed to natural or artificial fall armyworm infestations. In addition, larval mortality was significantly greater on CrylF corn hybrids compared with that on nonBt hybrids. These results demonstrate that corn hybrids containing CrylF represent an effective plant incorporated insecticidal protein management option for fall armyworm. In environments where fall armyworm may exceed damage thresholds and have to be carefully managed with foliar sprays, utilization of CrylF corn hybrids will allow growers flexibility in planting and an efficient means for managing infestations.

scholarly journals Baseline of Susceptibility to the Cry1F Protein in Mexican Populations of Fall Armyworm

2019 ◽  
Author(s):  
Maribel Rivero-Borja ◽  
J C Rodríguez-Maciel ◽  
J A Urzúa Gutiérrez ◽  
G Silva-Aguayo ◽  
Desmi I Chandrasena ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
San Luis ◽  
Geographical Populations ◽  
Percent Mortality ◽  
Neonate Larvae ◽  
Lepidoptera Noctuidae ◽  
Relative Inhibition ◽  
Mexican Populations

Abstract The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is currently the most important maize pest in Mexico. Its control is mainly based on the use of conventional insecticides. Additionally, Bt-maize expressing Cry1F protein represents an alternative to control this pest. We estimated the baseline susceptibility in Mexican populations of S. frugiperda to Cry1F protein. Twenty-eight geographical populations were field collected from Baja California Sur, Chihuahua, Coahuila, Durango, Sinaloa, Sonora, and Tamaulipas states. The F1 neonate larvae of each population were subjected to diet-overlay bioassay. After 7 d of Cry1F exposure, the percent mortality and the percent growth inhibition with respect to the untreated control were recorded (S-LAB). The LC50 ranged from 14.4 (6.3−24.0) (Cajeme 1, Sonora) to 161.8 ng/cm2 (92.0–320) (Ahumada 2, Chihuahua), while the LC95 was between 207.1 (145–363) (Obregón, Sonora) and 1,217 ng/cm2 (510.8–7,390.0) (Río Bravo 2, Tamaulipas). The sensitivity ratios at 50% mortality, (LC50 field/LC50 S-Lab) and 95% mortality were ≤6.45 and ≤5.05-fold, respectively. The 50% growth inhibition (GI50) ranged from 2.8 (0.008–9.3) (Obregón, Sonora) to 42.4 ng/cm2 (3.6–147.0) (Cajeme 1, Sonora). The GI95 was between 75.4 (San Luis Río Colorado, Sonora) to 1,198 ng/cm2 (Cajeme 1, Sonora). The relative inhibition at 50% of the growth, (RI50 = GI50 field /GI50 S-LAB) was ≤3.5 and at 95% (RI95) was ≤1.91-fold. These results indicated susceptibility to Cry1F protein in the evaluated populations of S. frugiperda.

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