Azadirachtin: an update

Mordue, A. J.; Blackwell, Alison

doi:10.1016/0022-1910(93)90001-8

Cited by 706 publications

(201 citation statements)

References 133 publications

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“…The effects of neem oils and extracts on insects are due to the presence of large quantities of limonoids, among which azadirachtin is the most complex and potent (Mordue (Luntz); Nisbet, 2000). Azadirachtin has strong antifeedant activity due to its effect on chemoreceptors; it affects ecdysteroid and juvenile hormone titers by blocking morphogenetic peptide hormone release, resulting in growth and molting aberrations, and it has direct histopathological effects on insect muscles, fat body, and gut epithelial cells (Mordue (Luntz); Blackwell, 1993). Therefore, neem acts as an insect growth regulator and as a feeding and oviposition deterrent (Mordue (Luntz); Nisbet, 2000;Isman, 2006).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of neem-based nanoformulations as alternative to control fall armyworm

2016

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Neem (Azadirachta indica A. Juss.) based insecticides are efficient for the control of various pest species, but their low residual effect and the lack of standardized formulations are problems for field use. Nanoformulations of neem in colloidal suspension or powder, containing the polymers poly (ε-caprolactone) (PCL), poly (β-hidroxibutirate) (PHB) or poly (methyl methacrylate) (PMMA), in capsules or spheres, were developed in order to reduce biodegradation of the active neem compounds and improve their residual effect. Corn leaves treated with the nanoformulations were offered to first instar larvae of fall armyworm during 10 days, observing mortality and larval weight and comparing it to a commercial neem oil and negative controls. The residual effect of the four most efficient nanoformulations was evaluated at 1, 3 and 7 days after spraying (DAS). Feeding preference tests with dual-choice (treatment vs. control) were performed with corn leaf disks at 1, 3 and 7 after DAS, and a preference index was determined 24 hours after larvae feeding on the disks. Some nanoformulations caused mortality up to 3 DAS and sublethal effects up to 7 DAS, but none outperformed the residual effect of commercial neem oil. All treatments showed phagodeterrence at 1 DAS, but this was lost over time. The short duration of the nanoformulations' efficacy suggests that there was little or no release of neem by the nanoparticles, so more studies are needed to improve the release kinetics of the nanoformulated products.Index terms: Azadirachta indica; Spodoptera frugiperda; polymeric nanoparticles; controlled-release formulations. RESUMOInseticidas à base de nim (Azadirachta indica A. Juss.) são eficientes para controle de várias espécies de pragas, porém o baixo efeito residual e a falta de padronização das formulações são um problema para uso em campo. Nanoformulações de nim em suspensão coloidal e em pó, contendo os polímeros poli-ε-caprolactona (PCL), poli-β-hidroxibutirato (PHB) e polimetilmetacrilato (PMMA) em cápsulas ou esferas, foram desenvolvidas, a fim de reduzir a biodegradação dos compostos ativos e melhorar seu efeito residual. Folhas de milho tratadas com as nanoformulações foram oferecidas a lagartas de primeiro ínstar de lagarta do cartucho durante 10 dias, observando-se a mortalidade e o peso larval e comparando com um óleo comercial de nim e controles negativos. O efeito residual das quatro nanoformulações mais eficientes foi avaliado aos 1, 3 e 7 dias, após a pulverização (DAP). Testes de preferência alimentar com dupla escolha (tratamento vs. controle) foram realizados com discos de folhas de milho aos 1, 3 e 7 DAP, e um índice de preferência foi determinado 24 horas após as lagartas se alimentarem nos discos foliares. Algumas nanoformulações causaram mortalidade até 3 DAP e efeitos subletais até 7 DAP, mas nenhuma superou o efeito residual do óleo comercial de nim. Todos os tratamentos apresentaram fagodeterrência em 1 DAP, mas esta foi perdida ao longo do tempo. A curta duração da eficiência das nanoformu...

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Section: Introductionmentioning

confidence: 99%

Evaluation of neem-based nanoformulations as alternative to control fall armyworm

2016

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“…The plant family Meliaceae has been the subject of search as one of the most promising sources of terpenoids with insect control properties, such as azadirachtin, a limonoid (tetranortriterpene) obtained from the seed kernels of the neem tree Azadirachta indica A. Juss. (Meliaceae) (Mordue and Blackwell, 1993). Likewise, López-Olguín (1998) showed that limonids isolated from the seed kernels of Trichilia havanesis Jacq.…”

mentioning

confidence: 99%

“…The antifeedant activity of limonoids and neoclerodanes appears to be due to their effects on chemosensory mouthparts (deterrent activity), but also through their post-ingestive toxic effects (Mordue and Blackwell, 1993). It is expected that insects will try to eliminate the compounds that are toxic by the induction of their detoxication systems, whereas no such induction is necessary for those compounds that are deterrents.…”

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confidence: 99%

Antifeedant activity and effects of terpenoids on detoxication enzymes of the beet armyworm, Spodoptera exigua (Hübner)

Caballero

López-Olguín

Ruíz

et al. 2008

Span. j. agric. res.

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It has been determined the antifeedant activity of a mixture of limonoids 1,7-di-O-acetylhavanensin and 3,7-di-Oacetylhavanensin (F18), isolated from seeds of Trichilia havanensis Jacq. (Meliaceae), and the neo-clerodane diterpene scutecyprol A, isolated from Scutellaria valdiviana (Clos) Epling (Labiatae), on fifth instar larvae of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). Choice and no-choice feeding assays, nutritional tests, and post-treatment studies indicated that scutecyprol A acts as an insect feeding deterrent against S. exigua, whereas the antifeedant activity of F18 is likely associated with a toxic mode of action. In addition, it was tested the hypothesis that S. exigua larvae will try to metabolize the compounds that are toxic by the induction of their detoxication systems, whereas no such induction happens for those compounds that are deterrents. The mixture of limonoids F18 significantly increased glutathione S-transferases during the treatment and post-treatment periods, whereas esterases were inhibited during the treatment period. On the contrary, scutecyprol A did not have any significant effect on any of the enzymatic processes. Hence, the metabolic response of S. exigua larvae to the ingestion of the secondary metabolites tested depends on their mode of action.Additional key words: esterases, glutathione S-transferases, limonoids, neo-clerodane diterpenes, nutritional indexes, Scutellaria, Trichilia. ResumenActividad antialimentaria de terpenoides y efectos sobre las enzimas de destoxificación de la gardama, Spodoptera exigua (Hübner) Se ha determinado la actividad antialimentaria de una mezcla de limonoides 1,7-di-O-acetilhavanensina y 3,7-di-O-acetilhavanensina (F18), aislados a partir de semillas de Trichilia havanensis Jacq. (Meliaceae), y del diterpeno neo-clerodano scutecyprol A, procedente de Scutellaria valdiviana (Clos) Epling (Labiatae), frente a larvas de 5º estadío de la gardama, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). Los resultados de ensayos de preferencia y no preferencia, de ensayos nutricionales y del estudio de los efectos post-ingestivos indican que el scutecyprol A actúa como disuasorio de la alimentación frente a larvas de S. exigua, mientras que la actividad antialimentaria de F18 está asociada a un modo de acción tóxico. Además, se ha comprobado la hipótesis de que las larvas de S. exigua tratan de metabolizar los compuestos que son tóxicos mediante la inducción de enzimas de destoxificación, mientras que esta inducción no es necesaria para aquellos compuestos que son disuasorios de la alimentación. La mezcla de limonoides F18 incrementó de forma significativa la actividad glutatión S-transferasa durante los periodos de tratamiento y post-tratamiento, mientras que la actividad esterasa se redujo durante el periodo de tratamiento. Por el contrario, el scutecyprol A no tuvo ningún efecto significativo sobre estos procesos enzimáticos. Se puede concluir, pues, que la respuesta metabólica en larvas de S. exigua depende del...

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“…3). DISCUSSION AND CONCLUSION Plants are the store-house of bio-active chemicals that have antifeedant, antiovipositional, growth disrupting and fecundity reducing properties towards different insects (Mordue (Luntz) & Blackwell, 1993). In the present study the neem seed kernel extract (NSKE) in combination with entomopathogenic nematodes have shown toxicity against subterranean termites.…”

Section: Infectivity Of Treated and Untreated S Glaseri On Worker Comentioning

confidence: 69%

Combined effect of Azadirachta indica and the entomopathogenic nematode Steinernema glaseri against subterranean termite, Reticulitermes flavipes

Murugan

Vasugi

2011

J Entomol Acarol Res

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-Laboratory study has been conducted on the bioactivities of entomopathogenic nematodes and neem seed kernel extract (NSKE) against worker termites of Reticulitermes flavipes. Neem at various concentrations did not affect the survivability of nematodes, whereas neem had considerable impact on the survivability of worker termites and this may be due to the presence of active neem compounds (Azadirachtin, salanin etc.). Mortality was 40% on 4th day at lower concentration of 1.0% NSKE treatment; whereas mortality has been increased to 70% at higher concentration (4.0%) on 4 th day. There was 100% mortality after the combined treatment with 4.0% NSKE + 600 infective juvenile Steinernema glaseri, even at the first day of the experiment. In the present experiment, neem extract does not affected the survival of the nematodes. Hence, nematode and neem extract can be used for soil-insect control particularly for the subterranean termites.

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Azadirachtin: an update

Cited by 706 publications

References 133 publications

Evaluation of neem-based nanoformulations as alternative to control fall armyworm

Evaluation of neem-based nanoformulations as alternative to control fall armyworm

Antifeedant activity and effects of terpenoids on detoxication enzymes of the beet armyworm, Spodoptera exigua (Hübner)

Combined effect of Azadirachta indica and the entomopathogenic nematode Steinernema glaseri against subterranean termite, Reticulitermes flavipes

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