Characterization of Toxicological and Neurophysiological Effects of Natural Product Based Chromenes to Fall Armyworm, Spodoptera frugiperda

2021 ◽  
Author(s):  
Sarah E McComic ◽  
Kumudini M Meepagala ◽  
Daniel R Swale
Keyword(s):  
Spodoptera Frugiperda ◽  
Developmental Trajectories ◽  
Fall Armyworm ◽  
Firing Activity ◽  
Central Neuron ◽  
Developmental Defects ◽  
Meta Position ◽  
Central Neurons ◽  
High Doses

Abstract We previously extracted and purified a chromene amide from Amyris texana and found this scaffold is moderately insecticidal and thus, this study aimed to test the insecticidal properties of 13 synthetically derived chromene analogs to the fall armyworm (FAW, Spodoptera frugiperda). Microinjection of chromenes with alcohol or aldehydes substitutions at the meta position on the benzopyran moiety led to moderate toxicity that was approximately 2- to 3-fold less toxic when compared to permethrin, yet microinjection of differently substituted chromenes exhibited little to no toxicity. Similarly, chromenes with alcohol or aldehydes substitutions at the meta position on the benzopyran moiety were among the most toxic chromenes studied through ingested exposure. In addition to acute toxicity, select chromenes significantly increased the percentage of developmental defects upon eclosion that prevented adult moths from being capable of flight, suggesting these compounds alter development. Interestingly, microinjection yielded differing signs of intoxication between alcohol and aldehyde substitutions where the alcohol resulted in flaccid paralysis and lethargy whereas aldehyde led to tonic contractions and hyperactivity. These contrasting signs of intoxication were also observed in electrophysiological assays where alcohol substitutions led to the depression of central neuron firing activity and aldehyde substitutions led to hyperexcitation of central neurons. In summary, the chromene amides led to acute lethality and/or altered developmental trajectories of FAW, yet the high doses required for acute mortality suggest these scaffolds hold relatively little promise for development into FAW-directed insecticides but may represent novel growth regulators for FAW.

Virulence and Genetic Characterization of Six Baculovirus Strains Isolated From Different Populations of Spodoptera Frugiperda (Lepidoptera: Noctuidae)

2021 ◽  
Author(s):  
Ingrid Zanella-Saenz ◽  
Elisabeth A. Herniou ◽  
Jorge E. Ibarra ◽  
Ma.Cristina Del Rincón-Castro ◽  
Ilse Alejandra Huerta-Arredondo
Keyword(s):  
Biological Control ◽  
Cell Cultures ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
The United States ◽  
Infection Mechanisms ◽  
Different Populations

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States. Five alphabaculoviruses (SfNPV-An2, SfNPV-Arg, SfNPV-Fx, SfNPV-Ho and SfNPV-Sin) and one betabaculovirus (SfGV-RV), were tested against FAW larvae, showing a wide diversity of virulence levels among strains when their estimated LC50s were compared, being SfNPVArg, SfNPV-Ho and SfNPV-Fx more virulent than SfNPV-An 2 , SfNPV-Sin and SfGV-RV. To determine any virulence difference in vitro studies of these isolates, Sf9 cell cultures were used. Interestingly, only ODVs from four of the test SfNPV strains showed infectivity on Sf9 cell cultures, and some differences in virulence were observed. Genomic restriction analyses and partial sequences of lef-8, lef-9 , and polh/granulin genes showed little variability among alphabaculoviruses, both, among them and with previously reported sequences. However, sequences from SfGV-RV were closer to previously reported sequences from the SfGVVG008 strain than the SfGV-Arg and SfGV-VG014 strains. The great difference in the in vivo virulence was not correlated with great similarity among the isolates. The characterization of these six baculoviruses isolates offers the basis for exploring their potential as biological control agents against S. frugiperda, as well the initial studies on their specific infection mechanisms, evolution, and ecology.

scholarly journals Molecular characterization and pathogenicity of isolates of Beauveria spp. to fall armyworm

2008 ◽  
Vol 43 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Andréa Almeida Carneiro ◽  
Eliane Aparecida Gomes ◽  
Claudia Teixeira Guimarães ◽  
Fernando Tavares Fernandes ◽  
Newton Portilho Carneiro ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Spodoptera Frugiperda ◽  
Sequence Comparison ◽  
Rapd Markers ◽  
Fall Armyworm ◽  
Its Sequence ◽  
Its Sequencing ◽  
Host Insect ◽  
Rdna Its

The objective of this work was to evaluate the pathogenicity of 24 Beauveria isolates to Spodoptera frugiperda larvae, and characterize them molecularly through rDNA-ITS sequencing and RAPD markers. Sequencing of rDNA-ITS fragments of 570 bp allowed the identification of isolates as B. bassiana or B. brongniarti by sequence comparison to GenBank. Sixty seven polymorphic RAPD fragments were capable to differentiate 20 among 24 Beauveria isolates, grouping them according to the derived host insect and to pathogenicity against maize fall armyworm larvae. Three RAPD markers were highly associated to the pathogenicity against S. frugiperda, explaining up to 67% of the phenotypic variation. Besides identification and molecular characterization of Beauveria isolates, ITS sequence and RAPD markers proved to be very useful in selecting the isolates potentially effective against S. frugiperda larvae and in monitoring field release of these microorganisms in biocontrol programs.

Characterization of a novel peptide with allatotropic activity in the fall armyworm Spodoptera frugiperda

2004 ◽  
Vol 122 (2) ◽  
pp. 69-78 ◽  
Author(s):  
Mohatmed Abdel-latief ◽  
Martina Meyering-Vos ◽  
Klaus H. Hoffmann
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm

scholarly journals Molecular and Biological Characterization of Spodoptera frugiperda Multiple Nucleopolyhedrovirus Field Isolate and Genotypes from China

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 777
Author(s):  
Chengfeng Lei ◽  
Jian Yang ◽  
Jia Wang ◽  
Jia Hu ◽  
Xiulian Sun
Keyword(s):  
Spodoptera Frugiperda ◽  
Field Isolate ◽  
Management Strategies ◽  
Fall Armyworm ◽  
Multiple Nucleopolyhedrovirus ◽  
Cloning Method ◽  
Occlusion Bodies ◽  
Colombian Isolate

The fall armyworm, Spodoptera frugiperda, is a new invading pest in China. The baculovirus Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) is a pathogenic agent of the fall armyworm and a potential agent for its control in integrated pest management strategies. In this work, we analyze the molecular and biological characteristics of an SfMNPV isolate collected from maize in China (SfMNPV-Hub). Two genotypes were further isolated from SfMNPV-Hub by an in vivo cloning method. The PstI profile of one genotype (SfHub-A) was similar to genotype A of the SfMNPV Colombian isolate, and the other (SfHub-E) was similar to genotype E of the Colombian isolate. The bioactivity of SfHub-A against second-instar S. frugiperda larvae was not significantly different from that of SfMNPV-Hub, whereas SfHub-E was 2.7–5.5 fold less potent than SfMNPV-Hub. The speed of kill of SfHub-E was quicker than SfMNPV-Hub, while SfHub-A acted slower than SfMNPV-Hub. Occlusion body (OB) production of SfHub-A in an S. frugiperda cadaver was significantly higher than that of SfMNPV-Hub, while SfHub-E yielded far fewer occlusion bodies (OBs) in the host larvae. These results provide basic information for developing a virus-based pesticide against the invading pest S. frugiperda.

scholarly journals Molecular characterization of the Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on maize in southern Rajasthan, India

2021 ◽  
Author(s):  
Sakthivel Ramesh Babu ◽  
Perumal Pachippan ◽  
Raja Manoharan ◽  
Sonika Joshi ◽  
Deepika Kalyan ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Caribbean Region ◽  
Plant Identification ◽  
African Region ◽  
Tropical America ◽  
Lepidopteran Pest ◽  
Lepidoptera Noctuidae

Abstract The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) is a polyphagous Lepidopteran pest, a native to tropical and sub-tropical America and recently it has invaded the African and Asian countries. Presently, the mitochondrial Cytochrome Oxidase Subunit I (COI) - gene based molecular characterization of FAW samples from the maize fields of southern Rajasthan has revealed the occurrence of corn and rice strains there. The occurrence of such S. frugiperda population of Rajasthan region could be traced its origin from the Florida-Caribbean region or African region. Further, the Tpi gene region analysis showed that the S.frugiperda forms found in the maize fields are only the corn strains. In the Indian Rajasthan populations of FAW, the Tpi-variant2 category is the highest one and is then followed by the Tpi-variant1 and Tpi-variant3 was unique with C and T at Tpie4192 and Tpie4198, respectively. Further research is needed towards the confirmation of these tentatively identified strains of S. frugiperda that would in turn helpful for the proper monitoring, host-plant identification and the effective management of such pests.

scholarly journals Metabolic Resistance in the Fall Armyworm: An Overview

2018 ◽  
Vol 10 (12) ◽  
pp. 426
Author(s):  
Indyra F. Carvalho ◽  
Larissa L. Erdmann ◽  
Larissa L. Machado ◽  
Ana Paula S. A. Rosa ◽  
Moisés J. Zotti ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
Abiotic Factors ◽  
Fall Armyworm ◽  
Detoxification Enzymes ◽  
American Continent ◽  
Metabolic Resistance ◽  
Glutathione S Transferases ◽  
High Doses ◽  
Lepidoptera Noctuidae ◽  
Detoxification Process

The Fall Armyworm (FAW), Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae), is one of the most important pests in the American continent and has recently become an invasive species in Africa. It’s main form of control is through the use of insecticides, however during the last 40 years, due to continuous spraying and high doses used along with FAW’s high adaptative capacity, developed resistance to different classes of chemical insecticides. One of the main mechanisms enabling resistance in the FAW is by detoxification enzymes or so-called metabolic resistance. P450s, Carboxylesterases and Glutathione-S-Transferases are the main families of enzymes believed to mediate the detoxification process. These enzymes in the FAW, although widely studied, have been difficult to generalize into patterns. This happens mainly because FAW populations can have high genetic variability within the species, as they have different biotypes meaning that they can be morphologically identical but physiologically different and consequently, enzymatic responses to toxic compounds can also differ. There are also differences due to the diversity of biomes in which S. frugiperda is found, which due to adaptations to different host plants and other abiotic factors, it’s hard to predict enzymatic responses in insecticide resistance. In this context we aimed to review the literature regarding these three main enzymes families involved in metabolic resistance in S. frugiperda, by cataloguing, analysing and summarizing these studies.

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