Biocontrol potential of Beauveria bassiana and Metarhizium anisopliae isolates from Turkey against Hyphantria cunea (Drury) (Lepidoptera: arctiidae) Larvae under laboratory and field conditions

Hyphantria cunea is one of the most important pest insects causing significant damage in many plant species. The present study aimed to evaluate the insecticidal activity of Turkey isolates of Beauveria bassiana and Metarhizium anisopliae against H. cunea larvae under laboratory and field conditions. B. bassiana isolates YK16, YK23 and YK26, and M. anisopliae isolates YK41 and YK45 were sprayed onto the larvae of H. cunea at the respective doses of 1x105 and 1x106 conidia mL-1 and monitored for seven days. Fungal isolates, bio-insecticide Bacillus thuringiensis and chemical insecticide diflubenzuron were used in field studies. Trials were carried out in five replications. All B. bassiana isolates caused 100% mortality on first instar larvae in laboratory trials. Mortality ratios ranged from 100 to 96% on second instar larvae. M. anisopliae isolates YK45 and YK41 caused 88 and 84%, and 81.33 and 77.11% mortalities for the first and second instar larvae, respectively. The mortality rates fluctuated between 91.78-72.89% for B. bassiana on third instar larvae in laboratory conditions. However, M. anisopliae isolates YK45 and YK41 caused 77.11 and 60.22% mortality on third instar larvae, respectively. In the field trials, B. bassiana YK23 displayed promising insecticidal activity with 80.60% mortality on second instar larvae of H. cunea. Other isolates as well caused mortalities ranging from 60.77 to 49.55%. The results revealed that some isolates of B. bassiana and M. anisopliae have potential to control H. cunea larvae. However, additional detailed studies need to be carried out to increase their effectiveness in field conditions.

Phytochemical composition of almond oil from Melia azedarach L. and its larvicidal, ovicidal, repellent and enzyme activities in Culex pipiens L

@#Melia azedarach L. (Meliaceae) is a botanical species with focal point of global research for its biological properties. The Melia azedarach tree is distinguished by its rapid growth, its adaptation to different temperate zones, as well as its insecticidal properties. All this made us think of exploiting it in biological control against different stages of mosquitoes. To this end, we aim, through the present work, to evaluate the effectiveness of Melia azedarach extracts against Culex pipiens mosquito. More specifically, our study focuses on determining the chemical composition of Melia almond oil, as well as the larvicidal, ovicidal and repellent activities on Culex pipiens L. mosquito as well as the activities of acetylcholinesterase (AChE) and glutathione-S-transferase (GST). Almond oil was extracted by a Soxhlet and subjected to gas chromatography–mass spectrometry (GC/MS). The yield was found to be 35.17%. The chemical composition revealed the presence of various phytoconstituents. A total of 7 compounds were identified, the main ones being 9,11-Octadecadienoic acid, methyl ester, (E,E)- (79.32%), 9-octadecenoic acid (Z)-, methyl ester (13.24%), hexadecanoic acid and methyl ester (3.69%). The larvicidal bioassays were performed according to the protocol recommended by the World Health Organization with concentrations varying from 20 to 80 mg/L depending on the exposure time (24, 48 and 72 hours). The almond oil exhibited remarkable larvicidal activity against fourth instar larvae and the lethal concentrations were determined (LC25= 23.70 mg/L, LC50=35.49 mg/L, LC90=79.61 mg/L). The results also showed that the oil caused an ovicidal activity with a significant effect on egg hatch. The recorded hatching percentages were respectively 88.79% and 72.40% for the LC25 and LC50, and this compared to the control series. Moreover, this oil exhibited significant repellency against adult mosquitoes. Furthermore, the enzymatic measurements performed on LC50 and LC90 treated larvae revealed a neurotoxic activity and a stimulation of the detoxification system as evidenced, respectively, by an inhibition of AChE and induction in GST activity. Overall, our data proved that Melia azedarach almond oil could be considered as a potent biorational alternative to synthetic insecticides for mosquito control.

Synergistic effects of binary mixtures of linalool with pyrethroids against fall armyworm / Efeitos sinérgicos de misturas binárias de linalol com piretroides contra lagarta-do-cartucho

The present work aimed to determine the toxicity of linalool and evaluate the lethal and toxic effects of linalool associated with pyrethroids in binary mixtures to fall armyworm (Spodoptera frugiperda). The insects used in the experiment were obtained from stock breeding initiated from larvae collected from conventional corn plants, grown in an experimental area, in the city of Uberlândia, Minas Gerais. Also, it was obtained essential oil from a variety of Ocimum basilicum, with a high content of linalool (80%), found naturally, as a measure of comparison of different linalool (97.5%) assays. Dose-response bioassays with 3rd instar larvae were performed to determine lethal dose for 50% mortality (LD50) of linalool. Toxicity tests were also performed with O. basilicum essential oil and with pyrethroid insecticides: deltamethrin and its commercial product (Decis 25 EC, Bayer®). After this, combinations between different doses of these products were made and applied on 3rd instar larvae of Spodoptera frugiperda (Smith). Linalool presented high toxicity to S. frugiperda (LD50 = 0.177 µL a.i. µL-1). It was observed neurotoxic effects after the linalool application since the insects presented an aspect of confusion, followed by extreme agitation and finally death. All binary mixtures caused mortality higher than the products applied alone (deltamethrin and linalool) used at 100% LD50, except to 75% LD50 deltamethrin added to 25% LD50 linalool, whose mortality did not differ the products alone, in 24 hours. It was obtained over 90% larval mortality when linalool was combined with 25% LD50 of deltamethrin, in 24 and 48 hours after application, and over 80% of mortality when linalool was combined with 25% LD50 of Decis, only in 48 hours after application. We conclude that linalool is a potential insecticidal and can be associated with pyrethroids to control of S. frugiperda. Further studies are required in order to evaluate the synergistic combinations against field populations of S. frugiperda.

O objetivo deste trabalho foi determinar a toxicidade do linalol e avaliar os efeitos tóxicos e letais do linalol associado a piretroides em misturas binárias para lagarta do cartucho do milho (Spodoptera frugiperda). Os insetos utilizados no experimento foram obtidos de criação estoque iniciada a partir de larvas coletadas em plantas de milho convencional, cultivado em área experimental, no município de Uberlândia, Minas Gerais. Também foi obtido óleo essencial de uma variedade de Ocimum basilicum, com alto teor de linalol (80%), encontrado naturalmente, como medida de comparação para ensaios com linalol (97.5%). Os bioensaios do tipo dose-resposta com larvas de 3º instar foram realizados para determinar a dose letal do linalol para 50% de mortalidade da população (DL50). Também foram realizados testes de toxicidade com óleo essencial de Ocimum basilicum e com inseticidas piretroides: deltametrina e seu produto comercial (Decis 25 EC, Bayer®). Em seguida, foram realizadas combinações entre diferentes doses desses produtos e aplicadas em larvas de 3º instar de Spodoptera frugiperda (Smith). De acordo com os resultados, observou-se que o linalol apresentou alta toxicidade para S. frugiperda (DL50 = 0,177 µL a. i. µL-1). Foram observados efeitos neurotóxicos após a aplicação do linalol, uma vez que os insetos apresentaram um aspecto de confusão, seguido de extrema agitação e, por fim, morte. Todas as combinações binárias causaram mortalidade maior que os produtos aplicados isoladamente (deltametrina e linalol) utilizando-se 100% da DL50, exceto para 75% DL50 de deltametrina somada a 25% DL50 de linalol, cuja mortalidade não diferiu dos produtos isolados, em 24 horas após a aplicação. Foi obtida mais de 90% de mortalidade de larvas quando se combinou linalol com 25% da DL50 de deltametrina, em 24 e 48 horas após a aplicação, e mais de 80% de mortalidade quando se combinou linalol com 25% da DL50 do produto comercial, somente 48 horas após a aplicação. Concluímos que o linalol é um potencial inseticida e pode ser associado a piretroides no controle de S. frugiperda. Mais estudos são necessários em vista de avaliar as combinações sinérgicas contra populações de campo de S. frugiperda.

Bioactivity of Schinus molle L. and Schinus terebinthifolia Raddi. Essential Oils on Anticarsia gemmatalis (Hübner 1818)

Abstract Anticarsia gemmatalis is one of the main pests of the soybean crop, being controlled mainly with agrochemicals. The environmental and health risks, as well as the development of resistance by the pests, has led to the search for alternative control measures, aiming to use more eco-friendly procedures. The objective of this research was to evaluate the chemical composition and the bioactivity of Schinus molle and Schinus terebinthifolia essential oils (EOs) on A. gemmatalis. The major compound in both EOs was α-pinene (60.04 wt.% for S. molle and 38.49 wt.% for S. terebinthifolia). Bioassays were carried out with third instar larvae, with five replicates and each replicate with ten larvae, totaling 50 larvae per treatment. The oils were incorporated in the artificial diet (0.1, 0.5, 1.0, 1.5, and 2.0% v/v). The controls were: water, Tween-80® 0.5% v/v, and novaluron 0.075% v/v. According to the Probit method, the S. terebinthifolia EO presented a LC50 of 1.74% v/v (1.58-1.97% v/v); it was not possible to determine the LC50 for the S. molle EO. The mortality percentage after 24 and 48 h was 52% and 30% at 2.0% v/v for S. terebinthifolia and S. molle oil, respectively. After 72 h, the mortality rate for S. molle EO have not changed; for S. terebinthifolia EO it increased to 70%; the larvae treated with the chemical control (synthetic insecticide) had a mortality of 100%.

Phytofabrication of silver nanoparticles using Annona reticulata and assessment of insecticidal and bactericidal activities

Aim: Silver nanoparticle synthesis using plant products is now popular due to its environment friendly, easy availability, simple procedure and fascinating properties. In this study, an attempt was made on leaf extract of Annona reticulata L silver nanoparticles to synthesize and to assess its bactericidal and insecticidal properties. Methodology: Using plant material for silver nanoparticle synthesis is one of the bottom up approaches of silver nanoparticle synthesis. In the present study leaf extract of Annona reticulata was used for nanoparticle synthesis. The synthesized nanoparticles were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Energy Dispersive X-Ray Analysis (EDAX). The bactericidal property was evaluated against E. coli, P. aeruginosa, S. aureus, B. subtilis and P. vulgaris where as insecticidal property was tested against mosquito larvae and Sitophilus oryzae. Results: The XRD spectrum confirmed the formation of silver nanoparticles. SEM observation showed that nanoparticles were 17.33 nm in size and spherical in shape. The EDAX result revealed the presence of silver in the suspension. Silver nanoparticles exhibited higher repellency against Sitophilus oryzae and feeding deterrence. The nanoparticles possessed a strong larvicidal activity when they were used against fourth instar larvae of mosquitoes. The silver nanoparticles showed bactericidal activity against Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Staphylococcus aureus and Escherichia coli. Interpretation: The present study strongly suggests that Annona reticulata leaf extract can be used to fabricate silver nanoparticles with potent insecticidal and bactericidal properties.

Insecticidal activities and mechanism of extracts from neem leaves against Oxya chinensis / Atividade e mecanismos inseticidas de extratos de folhas "neem" contra Oxya chinesis

In this study, neem leaves were successively extracted with petroleum ether, 95% ethanol and water and the insecticidal activities of these extracts against Oxya chinensis larvae were measured. The results showed that 95% ethanol extract gave the highest extraction yield and insecticidal activity, and it was further extracted with five different solvents. The petroleum ether extract from the 95% ethanol extract possessed the highest insecticidal activity with median lethal concentration values ranging from 14.93 to 55.66mg/mL. The gas chromatography-mass spectrometer analysis showed that the petroleum ether extract mainly composed of alkanes, olefin, esters and amide. The pathological examination revealed that the prominent lesions, including reduced regenerative cells in midgut and swelled and degenerated cylindrical cells, were observed in the 5th instar Oxya chinensis after treatment. The ultrastructural features showed that the cylindrical cells, microvilli and mitochondria were seriously damaged. These results suggested that the petroleum ether extract from neem leaves had potent insecticidal activity and could be a candidate insecticide.(AU)

Nesse estudo, folhas "neem" foram extraídas com sucesso com éter de petróleo, 95% de etanol e água, e as atividades inseticidas desses extratos foram medidas contra larvas de Oxya chinesis. Os resultados mostram que extrato com 95% de etanol deram o maior resultado de extração e atividade inseticida e foi então extraído utilizando mais cinco diferentes solventes. O éter de petróleo do extrato de 95% etanol apresentou maior atividade inseticida com concentração letal média variando de 14.93 a 55.66mg/mL. A análise por cromatografia de massa mostrou que o extrato de éter de petróleo está composto principalmente de alcanos, alcenos, ésteres e amidas. A avaliação patológica revelou que as lesões proeminentes, inclusive células regenerativas reduzidas no intestino e células cilíndricas edemaciadas e degeneradas foram observadas no quinto estágio de desenvolvimento da Oxya chinesis após tratamento. As características ultraestruturais mostraram que as células cilíndricas, microvilos e mitocôndrias apresentavam lesões graves. Esses resultados sugerem que o extrato de éter de petróleo de folhas de "neem" tem atividade inseticida potente e pode ser um candidato a inseticida.(AU)

A new disubstituted succinate from the roots of Tagetes erecta / 药学学报

Nine compounds were isolated from 95% ethanol extract of the roots of Tagates erecta by silica gel column chromatography and Sephadex LH-20 chromatography. Their structures were identified by spectroscopic data as 5-hydroxymethylfurfuryl methyl succinate (1), 5,7,3'-trihydroxyl-3,6,4'-trimethoxylflavone (2), syringic acid (3), 5,7,4'-trihydroxyl-3,6-trimethoxylflavone (4), patuletin-4'-methoxyl-7-O-β-D-glucopyranoside (5), patulitrin (6), 5,3'-dihydroxyl-3,6,4'-trimethoxylflavone-7-O-β-D-glucopyranoside (7), (2,2'-biththiophen)-5-ol (8), and 3-hydroxyl-4-methoxyl benzoic acid (9). Among them, compound 1 is a new disubstituted succinate and compound 8 was isolated from a natural resource for the first time. Compounds 2, 4, 5 and 9 were isolated from this genus for the first time. By measuring the biological activity and virulence of different compounds against soybean cyst nematode, it has found that compounds 1-8 exhibited a toxic effect on soybean cyst nematode, and ED50 values indicate that compounds 3 and 7 are the most potent, with ED50 values of 0.008 μg·mL-1.

Synthesis of new α-amino nitriles with insecticidal action on Aedes aegypti (Diptera: Culicidae)

Abstract Aedes aegypti is the principal vector of arboviral pathogens that may cause diseases as dengue fever, chikungunya and zika. The harmful environmental effects of commercial pesticides coalesced with the development of insecticide-resistant populations encourage the discovery and generation of new alternative products as a tool to reduce the incidence of vector-borne diseases. In this work, through the classic three component Strecker reaction of commercial benzaldehydes, cyclic secondary amines and KCN, a new series of nine α-amino nitriles, girgensohnine analogs, has been synthetized and screened for larvicide and adulticide properties against A. aegypti, one of the dominant vectors of dengue, chikungunya and zika in tropical and subtropical areas all over the world. Molecules 3 and 4 were identified as potential larvicidal agents with LC50 values of 50.55 and 69.59 ppm, respectively. Molecule 3 showed 100% of mortality after 2 h of treatment when a concentration of 30 ppm in adulticidal assays was evaluated. Additionally, in order to elucidate the mode of action of these molecules, their acetylcholinesterase (AChE) inhibitory properties were evaluated using the Ellman assay. It was found that the molecules possess a weak AChE inhibitory activity with IC50 values between 148.80 and 259.40 µM, indicating that AChE could not be a principal target for insecticide activity.

Larvicidal activity of Neem oil and three plant essential oils from Senegal against Chrysodeixis chalcites (Esper, 1789)

Objective: To evaluate the insecticide, larvicidal and repellent activity of the essential oils from Callistemon viminalis, Melaleuca leucadendron, and Hyptis suaveolens against Chrysodeixis chalcites and to compare it with neem oil (Azadirachta indica). Methods: The essential oils of the leaves of these aromatiques plants were extracted by steam distillation and contacts tests were carried out. Results: Essential oils in ethanol from Callistemon viminalis showed a higher biological activity than the neem with 100% larval mortality at the concentration of 2 μg/mL for 6 h, 100% and 90% in ethanol from Melaleuca leucadendron and Hyptis suaveolens, respectively at the concentration of 4 μg/mL for 24 h. By inhalation, the essential oils from Melaleuca leucadendron and of Hyptis suaveolens were more effective with mortality rates of larvae 100% and 50% respectively at 2 μg/L air applied after 24 h. Nevertheless, the neem has shown to be a repulsive plant and anti-nutritional plant. A significant difference in the percentages of consumption between leaves treated with neem oil and the control samples was observed (Newman-Keuls test) except for Melaleuca leucadendron. Conclusions: The results of the study highlight remarkable biocide, properties of tested extracts, which provides important opportunities for the development of biopesticides.

Larvicidal activity of Neem oil and three plant essential oils from Senegal against Chrysodeixis chalcites (Esper, 1789)

Objective:To evaluate the insecticide,larvicidal and repellent activity of the essential oils from Callistemon vimindis,Melaleuca leueadendron,and Hyptis suaveolens against Chrysodeixischalcites and to compare it with neem oil (Azadirachta indica).Methods:The essential oils of the leaves of these aromatiques plants were extracted by steam distillation and contacts tests were carried out.Results:Essential oils in ethanol from Callistemon viminalis showed a higher biological activity than the neem with 100％ larval mortality at the concentration of 2 μg/mL for 6 h,100％ and 90％ in ethanol from Melaleuca leucadendron and Hyptis suaveolens,respectively at the concentration of 4 μg/mL for 24 h.By inhalation,the essential oils from Melaleuca leucadendron and of Hyptis suaveolens were more effective with mortality rates of larvae 100％ and 50％ respectively at 2 μg/L air applied after 24 h.Nevertheless,the neem has shown to be a repulsive plant and anti-nutritional plant.A significant difference in the percentages of consumption between leaves treated with neem oil and the control samples was observed (Newman-Keuls test) except for Melaleucaleucadendron.Conclusions:The results of the study highlight remarkable biocide,properties of tested extracts,which provides important opportunities for the development of biopesticides.

Chemical constituents and insecticidal activity of essential oil of Paullinia pinnata L (Sapindaceae) / Compuestos químicos y actividad insecticida del aceite esencial de Paullinia pinnata L (Sapindaceae)

The chemical constituents and insecticidal activity of essential oil obtained by hydrodistillation of the leaves of Paullinia pinnata Linn (Sapindaceae) are being reported. The essential oil were analysed by using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). Different concentrations (50, 100, 150, 200 and 250 mg/mL) of P. pinnata essential oil prepared separately and diluted in dimethyl sulfoxide (DMSO) were tested on the maize weevil, Sitophilus zeamais. The main constituents of the oil were pentadecanoic acid (17.9%), isoaromadendrene epoxide (11.5%) and wine lactone (11.2%). Other significant compounds of the essential oil were eremophilene (6.9%) and phytol (6.2%). The essential oil displayed 100% mortality (fumigant toxicity) against S. zeamais adults at tested concentration of 150 mg/mL with lethal concentrations (LC50) of 51.87 mg/mL air. This is the first report on the chemical constituents and insecticidal activity of essential oil of P. pinnata and may be explore as a potential natural herbal plant for the control of insect pest.

Se informan los componentes químicos y la actividad insecticida del aceite esencial obtenido por hidrodestilación de las hojas de Paullinia pinnata Linn (Sapindaceae). El aceite esencial se analizó mediante cromatografía de gases (GC) y cromatografía de gases acoplada con espectrometría de masas (GC-MS). Se ensayaron diferentes concentraciones (50, 100, 150, 200 y 250 mg/ml) de aceite esencial de P. pinnata preparado separadamente y diluido en dimetilsulfóxido (DMSO) en el gorgojo de maíz, Sitophilus zeamais. Los componentes principales del aceite fueron ácido pentadecanoico (17,9%), isoaromadendreno epóxido (11,5%) y vino lactona (11,2%). Otros compuestos significativos del aceite esencial fueron eremophilene (6,9%) y phytol (6,2%). El aceite esencial mostró una mortalidad del 100% (toxicidad fumigante) contra los adultos de S. zeamais a una concentración de 150 mg/ml con concentraciones letales (CL50) de 51,87 mg/ml de aire. Este es el primer informe sobre la composición del aceite esencial de P. pinnata y su actividad insecticida. Puede ser explorado como una potencial planta herbácea natural para el control de la plaga de insectos.

Screening of plant extracts and fractions on Aedes aegypti larvae found in the state of Mato Grosso do Sul (linnaeus, 1762) (culicidae)

ABSTRACT The constant use of chemical insecticides for Aedes aegypti control has caused resistance in the mosquito populations. Thus, the objective of this study was to analyze the larvicidal potential of extracts and fractions of plants on A. aegypti larvae. The analysis included sixty one extracts and twenty five fractions of fifty botanical species at concentrations of 0.25; 0.12; 0.06 to 0.03 mg mL-1; 4 replications and one negative control of dechlorinate water and 1% DMSO; and a positive control with rotenone. The toxicity index in descending order with LC50 for the most active of the extracts selected were ethanol extract of Ormosea arborea (0.111 mg mL-1) seeds and ethanol extracts of leaves such as Piper hispidum (0.169 mg mL-1), Solanum variabile (0.188 mg mL-1), O. arborea (0.238 mg mL-1), Turnera umifolia (0.242 mg mL-1) and Piper hispidum (0.567 mg mL-1). For plant fractions, the most active were chloroform (0.192 mg mL-1) and hexane (0.342 mg mL-1) P. aduncum leaves, hexane fraction (0.415 mg mL-1) and methanol extract (0.625 mg mL-1) of Spermacocea latifolia leaves. Regarding the extract of T. umifolia single species, there is no bibliographic report on their degree of efficiency as an insecticide.

Expression of cry1Ab gene from a novel Bacillus thuringiensis strain SY49-1 active on pest insects

ABSTRACT In this study, the cry1Ab gene of previously characterized and Lepidoptera-, Diptera-, and Coleoptera-active Bacillus thuringiensis SY49-1 strain was cloned, expressed and individually tested on Ephestia kuehniella (Lepidoptera: Pyralidae) and Plodia interpunctella (Lepidoptera: Pyralidae) larvae. pET-cry1Ab plasmids were constructed by ligating the cry1Ab into pET28a (+) expression vector. Constructed plasmids were transferred to an Escherichia coli BL21 (DE3) strain rendered competent with CaCl2. Isopropyl β-D-1-thiogalactopyranoside was used to induce the expression of cry1Ab in E. coli BL21(DE3), and consequently, ∼130 kDa of Cry1Ab was obtained. Bioassay results indicated that recombinant Cry1Ab at a dose of 1000 µg g-1 caused 40% and 64% mortality on P. interpunctella and E. kuehniella larvae, respectively. However, the mortality rates of Bt SY49-1 strains' spore-crystal mixture at the same dose were observed to be 70% on P. interpunctella and 90% on E. kuehniella larvae. The results indicated that cry1Ab may be considered as a good candidate in transgenic crop production and as an alternative biocontrol agent in controlling stored product moths.

Oligomerization of Cry9Aa in solution without receptor binding, is not related with insecticidal activity

Background: Bacillus thuringiensis Cry toxins bind with different insect midgut proteins leading to toxin oligomerization, membrane insertion and pore formation. However, different Cry toxins had been shown to readily form high molecular weight oligomers or aggregates in solution in the absence of receptor interaction. The role of Cry oligomers formed in solution remains uncertain. The Cry9A proteins show high toxicity against different Lepidoptera, and no-cross resistance with Cry1A. Results: Cry9Aa655 protein formed oligomers easily in solution mediated by disulfide bonds, according to SDS-PAGE analysis under non-reducing and reducing conditions. However, oligomerization is not observed if Cry9Aa655 is activated with trypsin, suggesting that cysteine residues, C14 and C16, located in the N-terminal end that is processed during activation participate in this oligomerization. To determine the role of these residues on oligomerization and in toxicity single and double alanine substitution were constructed. In contrast to single C14A and C16A mutants, the double C14A-C16A mutant did not form oligomers in solution. Toxicity assays against Plutella xylostella showed that the C14A-C16A mutant had a similar insecticidal activity as the Cry9Aa655 protein indicating the oligomers of Cry9Aa formed in solution in the absence of receptor binding are not related with toxicity. Conclusions: The aggregation of Cry9Aa655 polypeptides was mediated by disulfide bonds. Cry9Aa655 C14 and C16C are involved in oligomerization in solution. These aggregate forms are not related to the mode of action of Cry9Aa leading to toxicity.

BIOATIVIDADE DE Solanum melongena L. E Capsicum annuum L. SOBRE Callosobruchus maculatus (COLEOPTERA: BRUCHIDAE) / Bioactivity of Solanum melongena L. and Capsicum annuum L. on Callosobruchus maculatus (Coleoptera: Bruchidae) / Bioactividad de Solanum melongena L. y Capsicum annuum L. en Callosobruchus maculatus (Coleoptera: Bruchidae)

O uso contínuo e indiscriminado de produtos químicos na agricultura pode trazer sérios prejuízos à saúde humana e ao meio ambiente. Uma opção é o emprego de plantas com ação inseticida. Diante do exposto, o objetivo desse trabalho foi avaliar a atividade inseticida do pó de folhas de Solanum melongena L. e Capsicum annuum L. contra Callosobruchus maculatus. O experimento foi conduzido no Laboratório de Entomologia da Universidade Federal de Campina Grande (UFCG), Campus de Pombal, Paraíba, Brasil. Os grãos de feijão-caupi foram tratados com os pós nas concentrações 0,0; 2,5; 5,0 e 10,0 % [100*(massa do pó/massa de grãos)] e realizados testes de sobrevivência e repelência contra C. maculatus. Os dados da sobrevivência foram analisados utilizando o teste de Log-rank (p ≤ 0,05), pelo método de D-collet e para a repelência utilizou-se o teste do Qui-Quadrado (p ≤ 0,05). Todos os pós e concentrações avaliadas foram repelentes contra C. maculatus, com exceção do pó de C. annuum na concentração de 2,5 %. No que se refere à sobrevivência, ambas as espécies vegetais causaram elevada mortalidade em C. maculatus, com morte total dos insetos em até 120 h.

The continuous and indiscriminate use of chemicals in agriculture can bring serious problems to human health and the environment. One option is the use of plants with insecticidal action. Given the above, the aim of this work was to evaluate the insecticide activity powder of leaves of Solanum melongena L. and Capsicum annuum L. against Callosobruchus maculatus in three concentrations. The experiment was conducted at the Laboratory of Entomology, Federal University of Campina Grande (UFCG), Campus de Pombal, Paraiba, Brazil. The grains of cowpea were treated with the powders in concentrations 0.0, 2.5, 5.0 and 10.0 % 6#91;100*(mass of powder/ mass of grains)] and performed tests of survival and repellency against C. maculatus. Survival data were analyzed using the Log-rank test (p ≤ 0.05) by D-collet method and the repellence we used the Chi-square test (p ≤ 0.05). All post and concentrations were repellent C. maculatus except the C. annuum powder at a concentration of 2.5 % that was not statistically significant difference. With respect to survival, both plant species caused high mortality on C. maculatus, with total kill insects up to 120 h.

El uso continuo y indiscriminado de productos químicos en la agricultura puede causar graves danos a la salud humana y al medio ambiente. Una opción es el uso de plantas con acción insecticida. Teniendo en cuenta lo anterior, el objetivo de este trabajo fue evaluar la actividad insecticida del polvo de las hojas de Solanum melongena L. y Capsicum annuum L. contra Callosobruchus maculatus en tres concentraciones. El experimento se realizó en el Laboratorio de Entomología de la Universidad Federal de Campina Grande (UFCG), Campus de Pombal, Paraiba, Brasil. Los granos de caupí fueron tratados con los polvos, en las concentraciones 0,0; 2,5; 5,0 a 10,0 % [100*(masa de polvo/masa de granos)] y se realizaron ensayos de supervivencia y repelencia contra C. maculatus. Los datos de supervivencia se analizaron mediante el análisis de Log-rank (p ≤ 0.05) por el método de D-Collet y para la repelencia se utilizó el análisis de Chi-cuadrado (p ≤ 0,05). Todos los polvos y las dosis evaluadas fueron repelentes contra C. maculatus, con la excepción del polvo de C. annuum a una dosis de 2,5 % que se observó ninguna diferencia estadística. Con respecto a la supervivencia, ambas especies de plantas causaron alta mortalidad en C. maculatus, con muerte total de los insectos hasta 120 h.

Comparison of Insecticidal Efficacy of Commonly Used TCM Pesticides and Preliminary Research on Compatibility / 中国中医药信息杂志

Objective To lay the foundation of new botanical pesticides by screening the insecticidal efficacy of 10 commonly used TCM pesticides.Methods Slide immersion method, trace intravenous drip method and insect body dipping method were respectively used to measure contact action of water extract and ethanol extract of the 10 commonly used TCM pesticides toTeranychus cinnbarinus,Brevicoryne brassicaeandMythimna separate, with herbal extracts to three kinds of insect pests of corrected mortality as observation indexes,Results Alcohol extracts for three kinds of insect pests were found to have contact action, and water extracts had no obvious effect. The Stemonae Radix alcohol extract had obvious contact action on three kinds of insect pests, and corrected mortality rates were 78.7%, 85.9%, and 96.7%, respectively; ethanol extracts of Angled Bittersweet, Sophorae Flavescentis Radix, Xanthii Fructus and Kansui Radix showed good contact action to Teranychus cinnbarinus,. The volume ratio of compatibility among Angled Bittersweet, Sophorae Flavescentis Radix, Xanthii Fructus and Kansui Radix was 2:1:1.5:1.5:1.5:1.5. The insecticidal activity to Teranychus cinnbarinus, was stronger than extracts of single herbs, and corrected mortality was 96.5%. Alcohol extracts of Stellera, hellebore, white mustard seed, and Xanthii Fructus showed good contact action toBrevicoryne brassicae. When the volume ratio of compatibility among Xanthii Fructus, Stemonae Radix, Stellera, and hellebore was 1:1.5:2:2, the activity toBrevicoryne brassicae increased. and corrected mortality was 93.1%.Conclusion The insecticidal activity will be enhanced after TCM extracts are under compatibility.

Menthane-type monoterpenes from branches and leaves of Illicium micranthum / 中草药

Objective: To study the chemical constituents from the branches and leaves of Illicium micranthum and insecticidal activitives on larvae of Bradysia odoriphaga. Methods: The chemical constituents were isolated and purified by silica gel, and Sephadex LH-20 column chromatography. Their structures were elucidated by physicochemical properties and spectroscopic analyses. The standard contact and stomach bioassay method was used to assess the effects of median lethal dose (LD50) of compound 2 on the demographic parameters of larvae of B. odoriphaga. Results: Five monoterpenoids were isolated from the ethyl acetate layer of methanol extract from the branches and leaves of I. micranthum. Compound 1, (-)-(1R*, 4S*)-1-(hydroxymethyl)-4-isopropylcyclohex-2-ene-1, 4-diol, was a new monoterpenoid and named as illicmicrene A, and the other compounds were identified as (1R, 2R, 4R)-1-methyl-4-(1-methylethyl)-1, 2, 4-cyclohexanetriol (2), 4-hydroxypiperitone (3), olibanumol C (4) and α, α-dimethyl-4-hydroxymethylbenzyl alcohol (5), respectively. Conclusion: Compound 1 is isolated as a new compound and compounds 2-5 are obtained from I. micranthum for the first time. Furthermore, compound 2 shows the insecticidal effects on larvae of B. odoriphaga with LD50 values at 30.4 mg/L after 48 h, at 22.5 mg/L after 72 h.

Insecticidal Activity of Ethyl Acetate Extracts from Culture Filtrates of Mangrove Fungal Endophytes

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration (LC50) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

Composição química e toxicidade de óleos essenciais para o pulgão-verde Schizaphis graminum (Rondani, 1852) / Chemical composition and toxicity of essential oils to the green-aphid Schizaphis graminum (Rondani, 1852)

Este trabalho teve como objetivo identificar e quantificar os constituintes dos óleos essenciais de Illicum verum, Ageratum conyzoides, Piper hispidinervum e Ocotea odorifera, bem como avaliar a toxicidade para o pulgão-verde Schizaphis graminum. A qualificação dos constituintes foi realizada por meio de um cromatógrafo gasoso + espectrômetro de massas, e a quantificação, por um cromatógrafo gasoso + detector de ionização de chama, ambos com uma coluna DB5. O método de hidrodestilação promoveu um rendimento (p/p) de 3,81% para I. verum, 0,46% para A. conyzoides, 2,85% para P. hispidinervum e 0,68% para O. odorífera. Já os componentes majoritários foram: precoceno (87,0%) e (E)-cariofileno (7,1%) para A. conyzoides; (E)-anetol (90,4%), limoneno (2,6%) e metil-chavicol (1,3%) para I. verum; metil-eugenol (81,2%) e safrol (10,6%) para Ocotea odorífera; e safrol (82,5%) e α-terpinoleno (13,4%) para P. hispidinervum. Pelos testes de toxicidade aguda (24 horas) com folhas de sorgo ou papel-filtro contaminados, verificou-se que o óleo de A. conyzoides foi o mais tóxico para o pulgão, com CL50 de 7,13 e 7,08 µL óleo/cm2 respectivamente, seguido por O. odorifera com CL50 de 11,80 e 103,00 µL óleo/cm2 respectivamente; I. verum de 51,80 µL óleo/cm2 em ambos os substratos; e o menos tóxico foi o óleo essencial de P. hispidinervum, com CL50 de 62,50 e 143,00 µL óleo/cm2, respectivamente. Dessa maneira, sugere-se que o uso dos óleos essenciais pode representar uma nova ferramenta em programas de manejo integrado de pragas.(AU)

The aim of this study was to assess the chemical composition of essential oils of Illicum verum, Ageratum conyzoides, Piper hispidinervum and Ocotea odorífera, as well as their toxicity to the green-aphid Schizaphis graminum. Compound identification was carried out with gas chromatography + mass spectrometry, and quantification with gas chromatography + flame ionization detector, both with DB5 column. The hydrodistillation process promoted oil yield of 3.81% for I. verum; 0.46% for A. conyzoides; 2.85 % for P. hispidinervum; and 0.68 % for O. odorífera. The major components from the oils of A. conyzoides was precocene (87.0%) and (E)-caryophyllene (7.1%); (E)-anethol (90.4%), limonene (2.6%) and methyl-chavicol (1.3%) for I. verum; methyleugenol (81.2%) and safrole (10.6%) for O. odorifera; and safrole (82.5%) and α-terpinolene (13.4%) for P. hispidinervum. The acute toxicity test (24 hours) performed by contact in sorghum leaves or contaminated filter-paper showed that the higher toxicity occur with essential oils of A. conyzoides, with LC50 of 7.01 and 7.01 µg oil/cm2, respectively; followed by O. odorifera, with LC50 of 17.10 and 66.70 µg oil/cm2, respectively; I. verum, with LC50of 66.40 and 65.40 µg oil/cm2, respectively; and low toxicity was observed for the P. hispidinervum essential oil, with LC50 of 64.00 and 143.00 oil/cm2, respectively. With the results obtained in this research, we can state that the use of these essential oils can be a new tool in integrated pest management.(AU)

Insecticidal activity of the essential oil of Thymus transcaspicus against Anopheles stephensi

Objective:To investigate the insecticidal activity of the essential oil of Thymus transcaspicus (T. transcaspicus) against Anopheles stephensi (An. stephensi). Methods:An. stephensi were exposed to 31, 63, 125 and 250 μg/L of essential oil of T. transcaspicus for 24 h. Results:The most toxicity was observed at 250 μg/L of essential oil with the LC50 values of 134.1 μg/L after 24 h. Conclusions:The essential oil of T. transcaspicus exhibited strong insecticidal activity against An. stephensi which can be attributed to its constituent especially carvacrol and thymol phenols.