ABSTRACT
Phytophagous mites are dangerous pests, causing economic losses to the world's crops. Nanotechnology is a promising field for pests and disease management, and enhancement of agricultural productivity. The aim of the study was to evaluation of the effectiveness of copper nanoparticles (CuNP) against all stages of eriophyid mite, the citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) and tetranychid mite, the citrus brown mite Eutetranychus orientalis (Klein) (Acari: Tetranychidae), and Tenuipalpid mite, the false spider mite, Brevipalpus obovatus Donnadieu (Acari: Tenuipalpidae). This includes its impacts on predacious mites, Amblyseius swirskii Athias-Henriot and Euseius scutalis (Athias-Henriot) (Acari: Phytoseiidae), on orange trees under field conditions. Five different concentrations of copper nanoparticles (40, 80, 160, 240, and 320 ppm), as well as the control (well water) were examined. The obtained results indicated that the mortality rate of both phytophagous and predacious mites was associated with an increase in the concentrations of copper nanoparticles. Copper nanoparticles were significantly effective in killing P. oleivora, E. orientalis and B. obovatus with minimal effects on A. swirskii and E. scutalis. The mortality percentage was 15.24, 20.32, 46.32, 78.97 and 86.37% for P. oleivora, 6.87, 9.86, 28.91, 56.30 and 77.52% for E. orientalis and 8.38, 23.50, 48.83, 68.80 and 84.08% for B. obovatus while the mortality percentage was 0.00, 0.56, 5.83, 9.91 and 15.19% for A. swirskii and 0.44, 3.96, 6.93, 8.63 and 21.39% for E. scutalis one week after exposure to 40, 80, 160, 240 and 320 ppm of copper nanoparticles, respectively. Moreover, the results showed that copper nanoparticles caused a reduction in the percentage of eggs hatching. The percentages of larvae hatching from eggs were 96.29, 80.00, 64.13, 45.66 and 32.17% for P. oleivora, 97.38, 83.28, 69.41, 48.01 and 35.29 for E. orientalis and 96.60, 76.92, 56.38, 40.55 and 33.28% for B. obovatus one week after exposure to copper nanoparticles at 40, 80, 160, 240 and 320 ppm respectively, compared with the control (well water). According to the results, the use of copper nanoparticles significant effect on reducing the population of phytophagous mites associated with orange trees, with low detrimental effects on predatory mites.
Os ácaros fitófagos são pragas perigosas, causando prejuízos econômicos às lavouras mundiais. A nanotecnologia é um campo promissor para o manejo de pragas e doenças, aumentando a produtividade agrícola. O objetivo do presente estudo foi avaliar a eficácia de nanopartículas de cobre (CuNP) em laranjeiras em condições de campo, contra todos os estágios das seguintes espécies: o ácaro eriofídeo, também chamado de ácaro da falsa ferrugem dos citros, ou Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae); o ácaro tetraniquídeo, também chamado de ácaro marrom dos citros, ou Eutetranychus orientalis (Klein) (Acari: Tetranychidae); e o ácaro Tenuipalpidae, também chamado de falso ácaro, ou Brevipalpus obovatus (Donnadieu) (Acari: Tenuipalpidae). Isso inclui seus impactos sobre ácaros predadores, como o Amblyseius swirskii Athias-Henriot e o Euseius scutalis (Athias-Henriot) (Acari: Phytoseiidae). Foram examinadas cinco diferentes concentrações de nanopartículas de cobre (40, 80, 160, 240 e 320 ppm), assim como o controle (água de poço). Os resultados obtidos indicaram que a taxa de mortalidade de ácaros fitófagos e predadores esteve associada ao aumento das concentrações de nanopartículas de cobre. As nanopartículas de cobre foram significativamente eficazes em matar o P. oleivora, o E. orientalis e o B. obovatus, com efeitos mínimos sobre o A. swirskii e o E. scutalis. As porcentagens de mortalidade foram: 15,24, 20,32, 46,32, 78,97 e 86,37% para P. oleivora; 6,87, 9,86, 28,91, 56,30 e 77,52% para E. orientalis; 8,38, 23,50, 48,83, 68,80 e 84,08% para B. obovatus; 0,00, 0,56, 5,83, 9,91 e 15,19% para A. swirskii; e 0,44, 3,96, 6,93, 8,63 e 21,39% para E. scutalis, uma semana após a exposição a 40, 80, 160, 240 e 320 ppm de nanopartículas de cobre, respectivamente. Além disso, os resultados mostraram que as nanopartículas de cobre causaram uma redução na porcentagem de eclosão dos ovos. As porcentagens de larvas eclodindo dos ovos foram: 96,29, 80,00, 64,13, 45,66 e 32,17% para P. oleivora; 97,38, 83,28, 69,41, 48,01 e 35,29 para E. orientalis; e 96,60, 76,92, 56,38, 40,58 e 33,29 para B. obovatus, uma semana após a exposição às nanopartículas de cobre a 40, 80, 160, 240 e 320 ppm, respectivamente, em comparação com o controle (água de poço). De acordo com os resultados, o uso de nanopartículas de cobre teve efeito significativo na redução da população de ácaros fitófagos associados às laranjeiras, com baixo efeito prejudicial aos ácaros predadores.
Subject(s)
Copper , Citrus sinensis/parasitology , Nanoparticles , Mites/drug effectsABSTRACT
Promising bioactivities of silver nanoparticles SNP urged researchers of different specialties to evaluate their field-respective activities. Bioactivity towards agricultural pests were the subject of limited publications. In the current study, SNP were synthesized and miticidal activity was evaluated towards old world date mite Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) and an associated predatory mite Neoseiulus barkeri Hughes (Phytoseiidae). Under laboratory conditions, SNP displayed significantly higher activity towards O. afrasiaticus (LC50 was 39.7 µg/mL) than N. barkeri (LC50 was 1587.9 µg/mL) which accounts for about 40 folds of selectivity against the pest. SNP exhibited ovicidal activity against laid eggs of O. afrasiaticus (LC50 was 67.8 µg/mL). In field, SNP (at 216 µg/mL) achieved slightly higher efficiency than in laboratory study, 86.5% of population reduction of O. afrasiaticus was achieved and only 18.5% of N. barkeri population was affected. SNP suppressed hatching of 57.1% of laid eggs of O. afrasiaticus. Residues of silver were determined using ICP-OES spectrometry. Initial residues reached 1.83 µg/mL after application then declined with time passing. Estimated daily intake (EDI) reached 1.28 µg/kg/day, calculated for the highest residues obtained and the highest consumption rate of date in the world. Hazard index (Hi) was 0.17 in average. The obtained level of residues appeared to be safe in terms of acute and chronic toxicity references.
Bioatividades promissoras de nanopartículas de prata (SNPs) incitaram pesquisadores de diferentes especialidades a avaliar suas atividades em campo. A bioatividade contra pragas agrícolas foi objeto de publicações limitadas. No presente estudo, SNPs foram sintetizadas, e a atividade miticida foi avaliada em relação ao ácaro Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) e um ácaro predador associado, Neoseiulus barkeri Hughes (Phytoseiidae). Em condições de laboratório, SNP apresentou atividade significativamente maior para O. afrasiaticus (LC50 foi de 39,7 µg/mL) do que N. barkeri (LC50 foi de 1.587,9 µg/mL), o que representa cerca de 40 vezes de seletividade contra a praga. O SNP exibiu atividade ovicida contra ovos postos de O. afrasiaticus (LC50 foi de 67,8 µg/mL). Em campo, o SNP (a 216 µg/mL) alcançou eficiência ligeiramente maior do que em estudo de laboratório; 86,5% de redução populacional de O. afrasiaticus foram alcançados e apenas 18,5% da população de N. barkeri foram afetados. O SNP suprimiu a eclosão de 57,1% dos ovos postos de O. afrasiaticus. Os resíduos de prata foram determinados usando espectrometria ICP-OES. Os resíduos iniciais atingiram 1,83 µg/mL após a aplicação e depois diminuíram com o passar do tempo. A ingestão diária estimada (IDE) atingiu 1,28 µg/kg/dia, calculada para os maiores resíduos obtidos e a maior taxa de consumo de tâmaras do mundo. O índice de risco (Hi) foi de 0,17 em média. O nível de resíduos obtido mostrou-se seguro em termos de referências de toxicidade aguda e crônica.
Subject(s)
Animals , Silver , Pest Control , Agricultural Pests , Tetranychidae , Nanoparticles/administration & dosage , MitesABSTRACT
Phytophagous mites are dangerous pests, causing economic losses to the world's crops. Nanotechnology is a promising field for pests and disease management, and enhancement of agricultural productivity. The aim of the study was to evaluation of the effectiveness of copper nanoparticles (CuNP) against all stages of eriophyid mite, the citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) and tetranychid mite, the citrus brown mite Eutetranychus orientalis (Klein) (Acari: Tetranychidae), and Tenuipalpid mite, the false spider mite, Brevipalpus obovatus Donnadieu (Acari: Tenuipalpidae). This includes its impacts on predacious mites, Amblyseius swirskii Athias-Henriot and Euseius scutalis (Athias-Henriot) (Acari: Phytoseiidae), on orange trees under field conditions. Five different concentrations of copper nanoparticles (40, 80, 160, 240, and 320 ppm), as well as the control (well water) were examined. The obtained results indicated that the mortality rate of both phytophagous and predacious mites was associated with an increase in the concentrations of copper nanoparticles. Copper nanoparticles were significantly effective in killing P. oleivora, E. orientalis and B. obovatus with minimal effects on A. swirskii and E. scutalis. The mortality percentage was 15.24, 20.32, 46.32, 78.97 and 86.37% for P. oleivora, 6.87, 9.86, 28.91, 56.30 and 77.52% for E. orientalis and 8.38, 23.50, 48.83, 68.80 and 84.08% for B. obovatus while the mortality percentage was 0.00, 0.56, 5.83, 9.91 and 15.19% for A. swirskii and 0.44, 3.96, 6.93, 8.63 and 21.39% for E. scutalis one week after exposure to 40, 80, 160, 240 and 320 ppm of copper nanoparticles, respectively. Moreover, the results showed that copper nanoparticles caused a reduction in the percentage of eggs hatching. The percentages of larvae hatching from eggs were 96.29, 80.00, 64.13, 45.66 and 32.17% for P. oleivora, 97.38, 83.28, 69.41, 48.01 and 35.29 for E. orientalis and 96.60, 76.92, 56.38, 40.55 and 33.28% for B. obovatus one week after exposure to copper nanoparticles at 40, 80, 160, 240 and 320 ppm respectively, compared with the control (well water). According to the results, the use of copper nanoparticles significant effect on reducing the population of phytophagous mites associated with orange trees, with low detrimental effects on predatory mites.
Subject(s)
Citrus sinensis , Citrus , Tetranychidae , Animals , Copper , Larva , Predatory Behavior , Pest Control, Biological/methodsABSTRACT
Promising bioactivities of silver nanoparticles SNP urged researchers of different specialties to evaluate their field-respective activities. Bioactivity towards agricultural pests were the subject of limited publications. In the current study, SNP were synthesized and miticidal activity was evaluated towards old world date mite Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) and an associated predatory mite Neoseiulus barkeri Hughes (Phytoseiidae). Under laboratory conditions, SNP displayed significantly higher activity towards O. afrasiaticus (LC50 was 39.7 µg/mL) than N. barkeri (LC50 was 1587.9 µg/mL) which accounts for about 40 folds of selectivity against the pest. SNP exhibited ovicidal activity against laid eggs of O. afrasiaticus (LC50 was 67.8 µg/mL). In field, SNP (at 216 µg/mL) achieved slightly higher efficiency than in laboratory study, 86.5% of population reduction of O. afrasiaticus was achieved and only 18.5% of N. barkeri population was affected. SNP suppressed hatching of 57.1% of laid eggs of O. afrasiaticus. Residues of silver were determined using ICP-OES spectrometry. Initial residues reached 1.83 µg/mL after application then declined with time passing. Estimated daily intake (EDI) reached 1.28 µg/kg/day, calculated for the highest residues obtained and the highest consumption rate of date in the world. Hazard index (Hi) was 0.17 in average. The obtained level of residues appeared to be safe in terms of acute and chronic toxicity references.
Subject(s)
Metal Nanoparticles , Mites , Phoeniceae , Tetranychidae , Animals , Metal Nanoparticles/toxicity , Pest Control, Biological , Predatory Behavior , Risk Assessment , Silver/pharmacologyABSTRACT
Mutations in the PAX6 gene that cause aniridia have been identified in various ethnicities but not in the Malaysian population. Therefore, the objective of this study was to investigate the PAX6 mutation in a Malaysian family with congenital aniridia. In this study, a complete ophthalmic examination was performed on a Dusun ethnic family with aniridia. Genomic DNA was extracted from the peripheral blood of the subjects and screened for the PAX6 gene mutation using polymerase chain reaction amplification high-resolution melting curve analysis (PCR-HRM) followed by confirmation via direct DNA sequencing. A heterozygous G deletion (c.857delG) in exon 7 causing a frame shift in PAX6 was identified in all affected family members. Genotype-phenotype correlation analysis revealed congenital cataract and all affected family members showed a similar spectrum of aniridia with no phenotypic variability but with differences in severity that were age-dependent. In summary, by using a PCR-HRM approach, this study is the first to report a PAX6 mutation in a Malaysian family. This mutation is the cause of the aniridia spectra observed in this family and of congenital cataract.