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1.
Pestic Biochem Physiol ; 165: 104555, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32359544

RESUMO

The development of genetic based techniques, specifically RNA interference (RNAi), has emerged as a powerful tool in novel pest management strategies for pestiferous coleoptera. The 28-spotted ladybird beetle, Henosepilachna vigintioctopunctata, is a dynamic foliar pest of solenaceous plants, primarily potato plants, and has quickly become one of the most important pests attacking many crops in Asian countries. In this study, we demonstrate the efficacy of dietary RNAi targeting vATPase B, which led to significant gene silencing. Downstream effects of vATPase B silencing appeared to be both time- and partial dose-dependent. Our results indicate that silencing of vATPase B caused a significant decrease in survival rate, as well as reduced the food stuffs consumption and inhibited the overall development of H. vigintioctopunctata. Furthermore, results demonstrate expression of insect melanism related genes, TH and DDC, was significantly up regulated under the dsvATPase B (RNAi molecule designed against vATPase B) treatment. The impact of oral dsvATPase B delivery on the survival of 1st, 3rd instars, and adults was investigated through bacterially expressed dsRNA. The effectiveness of RNAi-based gene silencing in H. vigintioctopunctata provides a powerful reverse genetic tool for the functional annotation of its genes. This study demonstrates that vATPase B may represent a candidate gene for RNAi-based control of H. vigintioctopunctata.


Assuntos
Besouros , RNA de Cadeia Dupla , Animais , Dieta , Controle de Pragas , Interferência de RNA
2.
Gene ; 743: 144605, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32199950

RESUMO

Atrijuglans hetaohei Yang (Lepidoptera: Gelechioidea), is one of the major pests that can seriously damage the walnut fruits. Neuropeptides and their receptors regulate most physiological functions in insects and represent new targets for the development of control agents. To identify the neuropeptides and their receptors from A. hetaohei, we sequenced and analyzed its head transcriptomic data, identified 32 neuropeptides and 39 neuropeptide receptor genes. Sequence comparisons and phylogenetic analyses suggest that A. hetaohei neuropeptides and receptor genes have high homology with those in Bombyx mori, Chilo suppressalis, Plutella xylostella and Helicoverpa armigera. Moreover, gene expression patterns revealed that neuropeptide genes such as AKH1, CP, MS and PTTH were expressed specifically in male head, while CAP3, DH, NPLP1, PBAN and SIF showed higher expression in the female head. Bur showed abdomen biased expression in both male and female. Neuropeptide receptor genes such as A8, A11, A15 and LGR were highly expressed in male head, whereas A24 and LGR2 were preferentially expressed in female head. This is the first sequencing, identification and expression analyses of neuropeptides and neuropeptide receptor genes from A. hetaohei. Our results could provide a powerful background that will facilitate the further investigations using transcriptomics to determine neuropeptides and their receptors presence, functions, and indicates potential targets in A. hetaohei for a novel pest management strategy.


Assuntos
Proteínas de Insetos/genética , Mariposas/genética , Neuropeptídeos/genética , Receptores de Neuropeptídeos/genética , Transcriptoma/genética , Animais , Clonagem Molecular , Feminino , Perfilação da Expressão Gênica , Genes de Insetos , Juglans/parasitologia , Masculino , Controle de Pragas/métodos , Filogenia , Fatores Sexuais
3.
PLoS Negl Trop Dis ; 14(3): e0008096, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203517

RESUMO

BACKGROUND: Vector-borne diseases are important causes of mortality and morbidity in humans and livestock, particularly for poorer communities and countries in the tropics. Large-scale programs against these diseases, for example malaria, dengue and African trypanosomiasis, include vector control, and assessing the impact of this intervention requires frequent and extensive monitoring of disease vector abundance. Such monitoring can be expensive, especially in the later stages of a successful program where numbers of vectors and cases are low. METHODOLOGY/PRINCIPAL FINDINGS: We developed a system that allows the identification of monitoring sites where pre-intervention densities of vectors are predicted to be high, and travel cost to sites is low, highlighting the most efficient locations for longitudinal monitoring. Using remotely sensed imagery and an image classification algorithm, we mapped landscape resistance associated with on- and off-road travel for every gridded location (3m and 0.5m grid cells) within Koboko district, Uganda. We combine the accessibility surface with pre-existing estimates of tsetse abundance and propose a stratified sampling approach to determine the most efficient locations for longitudinal data collection. Our modelled predictions were validated against empirical measurements of travel-time and existing maps of road networks. We applied this approach in northern Uganda where a large-scale vector control program is being implemented to control human African trypanosomiasis, a neglected tropical disease (NTD) caused by trypanosomes transmitted by tsetse flies. Our accessibility surfaces indicate a high performance when compared to empirical data, with remote sensing identifying a further ~70% of roads than existing networks. CONCLUSIONS/SIGNIFICANCE: By integrating such estimates with predictions of tsetse abundance, we propose a methodology to determine the optimal placement of sentinel monitoring sites for evaluating control programme efficacy, moving from a nuanced, ad-hoc approach incorporating intuition, knowledge of vector ecology and local knowledge of geographic accessibility, to a reproducible, quantifiable one.


Assuntos
Entomologia , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Modelos Biológicos , Modelos Estatísticos , Tecnologia de Sensoriamento Remoto , Animais , Custos e Análise de Custo , Humanos , Insetos Vetores , Gado , Controle de Pragas , Trypanosoma , Tripanossomíase Africana , Moscas Tsé-Tsé , Uganda , Doenças Transmitidas por Vetores
4.
PLoS One ; 15(2): e0213820, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053591

RESUMO

Tephritid fruit flies are among the most destructive horticultural pests posing risks to Australia's multi-billion-dollar horticulture industry. Currently, there are 11 pest fruit fly species of economic concern in Australia. Of these, nine are native to this continent (Bactrocera aquilonis, B. bryoniae, B. halfordiae, B. jarvisi, B. kraussi, B. musae, B. neohumeralis, B. tryoni and Zeugodacus cucumis), while B. frauenfeldi and Ceratitis capitata are introduced. To varying degrees these species are costly to Australia's horticulture through in-farm management, monitoring to demonstrate pest freedom, quarantine and trade restrictions, and crop losses. Here, we used a common species distribution model, Maxent, to assess climate suitability for these 11 species under baseline (1960-1990) and future climate scenarios for Australia. Projections indicate that the Wet Tropics is likely to be vulnerable to all 11 species until at least 2070, with the east coast of Australia also likely to remain vulnerable to multiple species. While the Cape York Peninsula and Northern Territory are projected to have suitable climate for numerous species, extrapolation to novel climates in these areas decreases confidence in model projections. The climate suitability of major horticulture areas currently in eastern Queensland, southern-central New South Wales and southern Victoria to these pests may increase as climate changes. By highlighting areas at risk of pest range expansion in the future our study may guide Australia's horticulture industry in developing effective monitoring and management strategies.


Assuntos
Distribuição Animal , Mudança Climática , Monitorização de Parâmetros Ecológicos/métodos , Modelos Estatísticos , Tephritidae , Animais , Austrália , Geografia , Horticultura/métodos , Controle de Pragas/métodos , Estações do Ano , Análise Espacial , Temperatura
5.
J Fish Biol ; 96(2): 549-553, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31875320

RESUMO

Invasion of armoured catfish, Pterygoplichthys spp., is a major threat to global aquatic biodiversity, and developing effective strategies for their control and eradication is both a concern and a research priority. A length-based population assessment of invasive Pterygoplichthys pardalis in southern India, a hotspot for endemic aquatic biodiversity, indicated that rapid growth, high growth performance index and continuous recruitment have aided their successful invasion. Increasing fishing pressure on the adults is not adequate for population management, and only targeting young individuals (<30 cm) will result in overexploitation and population collapse.


Assuntos
Biodiversidade , Peixes-Gato/classificação , Espécies Introduzidas , Animais , Índia , Controle de Pragas/métodos
6.
Chemosphere ; 240: 124926, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726586

RESUMO

Insect pollinators such as bees and syrphid flies play a crucial role in pollinating many food crops, and their diversity and abundance may be influenced by pesticide application patterns. Over three years, we assessed the ecotoxicological impacts on the diversity and abundance of bees and syrphid flies between reduced-risk pesticide programs and standard, conventional pesticide programs in paired plots at six spatially distinct commercial apple orchards. In particular, we quantified pesticide inputs, environmental impact, and community response of bees and syrphids to these pesticide programs. Relative environmental impacts of reduced-risk versus conventional pesticide programs were calculated using Environmental Impact Quotient analysis, while ecological impacts were characterized by assessing the abundance, richness, and species assemblages of bees and syrphids. Adopting a reduced-risk pesticide program for apple pest management reduced the use (in terms of kg a.i./ha) of organophosphate and pyrethroid insecticides by approximately 97.6% and 100% respectively, but increased the use of neonicotinoid pesticides (acetamiprid, imidacloprid, thiacloprid) by 40.4% compared to the orchards under standard conventional pesticide program. Regardless of pesticide inputs, abundance, richness and species assemblages of bees and syrphids did not differ between reduced-risk and conventional pest management programs. However, the environmental impact of pesticide inputs was reduced by 89.8% in reduced-risk pesticide program. These findings suggest that the implementation of reduced-risk pesticide program may reduce pesticide environmental impact, in addition to being safer to farm workers, without adversely affecting the robust community composition of bees and syrphids in commercial apple orchards in the mid-Atlantic region.


Assuntos
Produtos Agrícolas , Malus , Controle de Pragas/métodos , Praguicidas , Polinização , Animais , Abelhas , Ecotoxicologia , Meio Ambiente , Insetos , Inseticidas , Neonicotinoides , Nitrocompostos , Piretrinas , Tiazinas
7.
Res Vet Sci ; 128: 293-298, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869595

RESUMO

Feral pigeons have increased in urban settings worldwide becoming a potential health risk for humans and other animals. Control and surveillance programs are essential to prevent the possible transmission of zoonotic pathogens carried by pigeons. A surveillance program was carried out in Madrid City (Spain) during 2005-2014 to determine the role of urban pigeons as carriers of zoonotic agents comparing these results with studies performed elsewhere in the last fifteen years. A total of 1372 pigeons were randomly captured and tested for detection of Antimicrobial susceptibility and genetic heterogeneity of Campylobacter and Salmonella isolates were determined. During the first phase (August 2005-July 2010), 428 animals were analyzed individually, while in the second period (August 2010-December 2014), 944 pigeons were analyzed in pools (n = 2-3 in 2010 and n = 5-6 in 2013 and 2014). The most prevalent pathogen during the first phase was Campylobacter spp., (6.57%, 95% confidence interval 3.05-12.10%) followed by Salmonella spp. (4.41%, 95% CI: 2.30-7.58%) and C. psittaci (2.56%, 95% CI: 0.70-6.53%)]. The PCR techniques, used during the 2010-2014 phase of the study, confirmed the presence of Campylobacter spp. (prevalence of 0-14.83%) and C. psittaci (0-12,94%) among pigeons of Madrid. Antimicrobial susceptibility testing suggested low levels of resistance. Presence of zoonotic agents in feral pigeons highlights the importance of surveillance programs on this species, although the relative low prevalence found suggests a limited risk to Public and Animal Health in Madrid.


Assuntos
Doenças das Aves/transmissão , Columbidae/microbiologia , Reservatórios de Doenças/microbiologia , Monitoramento Epidemiológico , Animais , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/transmissão , Aves , Campylobacter/isolamento & purificação , Chlamydophila psittaci/isolamento & purificação , Humanos , Controle de Pragas , Prevalência , Saúde Pública , Salmonella/isolamento & purificação , Espanha/epidemiologia , Zoonoses/epidemiologia , Zoonoses/prevenção & controle , Zoonoses/transmissão
8.
Ecotoxicol Environ Saf ; 187: 109849, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677571

RESUMO

Harmonia axyridis is an important predator of several pest species and is part of many Integrated Pest Management (IPM) programs. To assess the risks of pesticide application to H. axyridis, we studied the effects of sulfoxaflor on H. axyridis larvae. At 72 h after treatment, the acute toxicity LR50 was 311.9476 g a. i. ha-1 by the residual contact method. This result indicated low-contact toxicity against second-instar H. axyridis larvae. The LR50 of the F1 generation decreased from 69.96 to 36.41 g a. i. ha-1 in a long-term toxicity test. The daily hazard quotient (HQ) for H. axyridis larvae lowered the safety threshold value in the first 5 d. However, the HQ values were greater than 2 during days 6-18 after sulfoxaflor treatments. We determined the No Observed Effect Application Rates of sulfoxaflor on the survival (<11.25 g a. i. ha-1), duration of larval and pupal stages (45 g a. i. ha-1), adult stage (90 g a. i. ha-1), total pre-oviposition period, adult pre-oviposition period (45 g a. i. ha-1), and reproduction (11.25 g a. i. ha-1). Pupation, adult emergence, and eggs counts of H. axyridis were reduced after sulfoxaflor treatments. The predation ability and population demography parameters were significantly impaired by higher application rates. At 90 g a. i. ha-1 or less, sulfoxaflor was slightly harmful to H. axyridis but a rate of 180 g a. i. ha-1 was moderately harmful. These results demonstrated that sulfoxaflor is harmful to H. axyridis when applied at high application rates.


Assuntos
Besouros/efeitos dos fármacos , Larva/efeitos dos fármacos , Resíduos de Praguicidas/toxicidade , Pupa/efeitos dos fármacos , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Besouros/fisiologia , Relação Dose-Resposta a Droga , Feminino , Larva/fisiologia , Dose Letal Mediana , Controle de Pragas , Comportamento Predatório/efeitos dos fármacos , Pupa/fisiologia , Reprodução/efeitos dos fármacos , Testes de Toxicidade
9.
Environ Sci Pollut Res Int ; 26(35): 36048-36054, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31745787

RESUMO

The essential oils (EOs) from aerial parts of Saussurea amara (L.) DC. (SAEO) and Sigesbeckia pubescens Makino (SPEO) were analyzed for their chemical composition by GC-MS, and their repellent activities against adults of the red flour beetle, Tribolium castaneum Herbst, as well as the booklouse, Liposcelis bostrychophila Badonnel, were evaluated for the first time. Results of GC-MS analysis indicated that both SAEO and SPEO were characterized by high content of sesquiterpenoids (relative content > 70%) including oxygenated sesquiterpenoids. The two oil samples and their major component caryophyllene oxide exerted beneficial repellent effects on T. castaneum and L. bostrychophila at 2 and 4 h post-exposure. At 4 h post-exposure, the PR value of caryophyllene oxide could still reach 92% (class V) against T. castaneum at minimum testing concentration of 3.15 nL/cm2, and this compound was observed to result in the greatest repellency (PR = 100%) against L. bostrychophila at 12.63 nL/cm2. This work confirmed the potent repellent efficacy of SAEO and SPEO for controlling pest damage and suggested their potential to be developed into botanical repellents.


Assuntos
Repelentes de Insetos/toxicidade , Óleos Voláteis/toxicidade , Saussurea/fisiologia , Sesquiterpenos/toxicidade , Animais , Asteraceae , Besouros/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Insetos/efeitos dos fármacos , Inseticidas/análise , Óleos Voláteis/química , Controle de Pragas , Tribolium/efeitos dos fármacos
10.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 535-537, 2019 Oct 16.
Artigo em Chinês | MEDLINE | ID: mdl-31713388

RESUMO

OBJECTIVE: To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. METHODS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. RESULTS: The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. CONCLUSIONS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.


Assuntos
Moluscocidas , Niclosamida , Controle de Pragas , Caramujos , Animais , Imersão , Controle de Pragas/métodos , Inquéritos e Questionários , Suspensões , Ondas de Maré , Áreas Alagadas
11.
Pestic Biochem Physiol ; 161: 33-46, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31685194

RESUMO

Chitin is a structural component of the arthropod cuticular exoskeleton and the peritrophic matrix of the gut, which play crucial roles in growth and development. In the past few decades, our understanding of the composition, biosynthesis, assembly, degradation, and regulation of chitinous structures has increased. Many chemicals have been developed that target chitin biosynthesis (benzoyphenyl ureas, etoxazole), chitin degradation (allosamidin, psammaplin), and chitin regulation (benzoyl hydrazines), thus resulting in molting deformities and lethality. In addition, proteins that disrupt chitin structures, such as lectins, proteases, and chitinases have been utilized to halt feeding and induce mortality. Chitin-degrading enzymes, such as chitinases are also useful for improving the efficacy of bio-insecticides. Transgenic plants, baculoviruses, fungi, and bacteria have been engineered to express chitinases from a variety of organisms for control of arthropod pests. In addition, RNA interference targeting genes involved in chitin pathways and structures are now being investigated for the development of environmentally friendly pest management strategies. This review describes the chemicals and proteins used to target chitin structures and enzymes for arthropod pest management, as well as pest management strategies based upon these compounds, such as plant-incorporated-protectants and recombinant entomopathogens. Recent advances in RNA interference-based pest management, and how this technology can be used to target chitin pathways and structures are also discussed.


Assuntos
Artrópodes/metabolismo , Quitina/metabolismo , Animais , Artrópodes/efeitos dos fármacos , Quitina/química , Quitinases/metabolismo , Inseticidas/farmacologia , Controle de Pragas/métodos , Interferência de RNA
13.
PLoS Negl Trop Dis ; 13(10): e0007767, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31652261

RESUMO

OBJECTIVE: To evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir. METHODS: A stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household. RESULTS: A total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs. CONCLUSION: The synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.


Assuntos
Doenças do Cão/prevenção & controle , Inseticidas/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/prevenção & controle , Psychodidae/metabolismo , Atrativos Sexuais/metabolismo , Atrativos Sexuais/farmacologia , Animais , Brasil , Controle de Doenças Transmissíveis/métodos , Reservatórios de Doenças , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Cães , Feminino , Humanos , Incidência , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Leishmaniose Visceral/veterinária , Masculino , Carga Parasitária , Controle de Pragas/métodos , Inquéritos e Questionários
14.
Plant Dis ; 103(11): 2764-2770, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31490090

RESUMO

Fusarium wilt (Fusarium oxysporum f. sp. lycopersici), root-knot nematodes (Meloidogyne spp.), and purple nutsedge (Cyperus rotundus L.) are among the most damaging soilborne pests for tomato (Lycopersicon esculentum Mill.) production in the southeastern United States. Allyl isothiocyanate (allyl ITC) was evaluated as a potential fumigant alternative for control of soilborne pathogens, nematodes, and weeds. Shank- or drip-injected allyl ITC at rates ranging from 221 to 367 kg ha-1 exhibited excellent performance, reducing the recovery of total F. oxysporum from treated soils. Shank- or drip-injected allyl ITC at 367 kg ha-1 provided equivalent control of C. rotundus compared with 1,3-dichloropropene + chloropicrin and metam potassium, respectively. Totally impermeable film (TIF) did not further reduce the recovery of F. oxysporum and various nematodes from soil treated with allyl ITC compared with virtually impermeable film (VIF). However, TIF mulch significantly improved C. rotundus control versus shank- or drip-injected allyl ITC treatments under VIF mulch. Overall, allyl ITC is an effective methyl bromide alternative against F. oxysporum, C. rotundus, and plant-parasitic nematodes Criconemella spp. and Hoplolaimus spp. in plasticulture tomato production.


Assuntos
Agricultura , Lycopersicon esculentum , Controle de Pragas , Agricultura/métodos , Animais , Cyperus/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Isotiocianatos/farmacologia , Lycopersicon esculentum/microbiologia , Lycopersicon esculentum/parasitologia , Controle de Pragas/métodos , Solo/parasitologia , Microbiologia do Solo , Sudeste dos Estados Unidos , Tylenchoidea/efeitos dos fármacos
15.
Pest Manag Sci ; 75(12): 3392-3404, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31392825

RESUMO

BACKGROUND: Slugs and snails constitute major crop pests. Withdrawal of metaldehyde has prompted a search for more environmentally friendly yet fast acting molluscicides. This study investigated the response of representative molluscs to conidia and volatile organic compounds (VOCs) of the insect pathogenic fungus Metarhizium brunneum Petch. RESULTS: Conidia of M. brunneum had antifeedant/repellent properties with repellency being dependent upon the fungal strain and conidia concentration. Three commonly produced fungal VOCs, 1-octene, 3-octanone and 1-octen-3-ol, were repellent at low doses (1-5 µL) but could kill slugs and snails on contact or fumigation. At the highest dose tested (10 µL), 100% mortality was achieved for Cornu aspersum Muller (garden snail) and Derocerus reticulatum Muller (grey field slug) within 1 h post-treatment with the first deaths being recorded in <11 min. Aqueous formulations (20% v/v) of the most potent VOCs, 3-octanone and 1-octen-3-ol, could be sprayed onto plants to kill or drive the pest of the crop with no phytotoxic effects. CONCLUSION: The sensitivity of terrestrial molluscs to 3-octanone and 1-octen-3-ol and the ephemeral nature of these compounds makes these excellent candidates for development as mollusc repellents or molluscicides. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Gastrópodes , Metarhizium/química , Moluscocidas , Controle de Pragas , Compostos Orgânicos Voláteis , Alcenos , Animais , Relação Dose-Resposta a Droga , Cetonas , Octanóis , Esporos Fúngicos
16.
Molecules ; 24(15)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374818

RESUMO

Using nanotechnology to develop new formulations of pesticides is considered a possible option in enhancing the efficiency, safety, and photostability of pesticides under various climatic conditions. In the present study, two novel nanoformulations (NFs) were successfully prepared based on nano-delivery systems for emamectin benzoate (EMB) by loading it on cellulose nanocrystals (CNCs) and silicon dioxide nanoparticles (SNPs) as carriers through a freeze-drying method. The synthesized nanoformulations were examined using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and dynamic light scattering (DLS). The results showed that SNPs and CNCs had a loading efficiency of 43.31% and 15.04% (w/w) for EMB, respectively, and could effectively protect EMB from photolysis under UV radiation. The LC50 values for EMB + SNPs, EMB + CNCs, and EMB commercial formulation against Phenacoccus solenopsis were 0.01, 0.05, and 0.31 µg/mL, respectively, indicating that both NFs were more effective than the EMB commercial formulation. This work seeks to develop new nano-carriers for potential applications of pesticides in plant protection, which will reduce the recommended dose of pesticides and thereby decrease the amount of pesticide residue in food and the environment.


Assuntos
Hemípteros/efeitos dos fármacos , Ivermectina/análogos & derivados , Nanopartículas/química , Animais , Celulose/química , Hemípteros/patogenicidade , Ivermectina/síntese química , Ivermectina/química , Ivermectina/farmacologia , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Controle de Pragas/métodos , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
17.
PLoS Negl Trop Dis ; 13(8): e0007604, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31386661

RESUMO

Bubonic is the most prevalent plague form in Madagascar. Indoor ground application of insecticide dust is the conventional method used to control potentially infected rodent fleas that transmit the plague bacterium from rodents to humans. The use of bait stations is an alternative approach for vector control during plague epidemics, as well as a preventive control method during non-epidemic seasons. Bait stations have many advantages, principally by reducing the amount of insecticide used, lowering the cost of the treatment and minimizing insecticide exposure in the environment. A previous study reported promising results on controlling simultaneously the reservoir and vectors, when slow-acting rodenticide was incorporated in bait stations called "Boîtes de Kartman". However, little evidence of an effective control of the fleas prior to the elimination of rodents was found. In this study, we evaluated bait stations containing insecticide powder and non-toxic attractive rodent bait for their potential to control rat fleas. Its efficacy was compared to the standard method. The impact of both methods on indoor and outdoor rodent fleas, as well as the human household flea Pulex irritans were analyzed at different time points after treatments. Bait stations did not cause any significant immediate or delayed reduction of rat fleas and increasing the number of operational bait stations per household did not significantly improve their efficacy. Insecticide ground dusting appeared to be the most efficient method to control indoor rat fleas. Both methods appeared to have little impact on the density of outdoor rat fleas and human fleas. These results demonstrate limited effectiveness for bait stations and encourage the maintenance of insecticide dusting as a first-line control strategy in case of epidemic emergence of plague, when immediate effect on rodent fleas is needed. Recommendations are given to improve the efficacy of the bait station method.


Assuntos
Infestações por Pulgas/prevenção & controle , Inseticidas/farmacologia , Controle de Pragas/métodos , Peste/prevenção & controle , Sifonápteros/efeitos dos fármacos , Animais , Humanos , Insetos Vetores/efeitos dos fármacos , Madagáscar , Peste/transmissão , Ratos , Roedores , Sifonápteros/microbiologia , Yersinia pestis
19.
Biosci. j. (Online) ; 35(4): 1220-1226, july/aug. 2019. tab
Artigo em Inglês | LILACS | ID: biblio-1048867

RESUMO

The State ofRio Grande do Sul is a major producer of grapes in Brazil, highlighting the Serra Gaúcha as the main producing region. In the pursuit of good quality in grapes it is essential the control of pests, especially insects. This study highlights the incidence of wasps, which cause serious damage at harvest time. This study aimed to characterize the community of social wasps (Hymenoptera, Vespidae) through faunal analysis and to examine the relationship of these insects with injuries to the grape berries in vineyards of Bento Gonçalves, Rio Grande do Sul State. Therefore, active search were made in January and February 2014, followed by analysis of frequency, constancy, abundance, dominance and diversity. Ten species of wasps were able to use grape berries as food. The two dominant species were Polybia ignobilis and P. minarum, however, Synoeca cyanea has greater ability to break the intact berries. Other three species, Polistes cavapytiformis, P. versicolor and Brachygastra lecheguana, were also able to break the skin of grapes, but of damaged berries.


O Rio Grande do Sul é o maior produtor de uvas no Brasil, destacando-se a Serra Gaúcha como principal região produtora. Na busca de qualidade das uvas é fundamental o controle de pragas, especialmente insetos. Este trabalho identifica a incidência de vespas que acarretam graves danos na época de colheita. A pesquisa foi conduzida com o objetivo caracterizar a assembleia de vespas sociais (Hymenoptera, Vespidae) através de análise faunística e a relação destas com injúrias as bagas, em parreirais do município de Bento Gonçalves, Rio Grande do Sul. Para tanto, foram realizadas coletas ativas nos meses de janeiro efevereiro de 2014, realizando-se análise de frequência, constância, abundância, dominância e diversidade da comunidade. Foram identificadas 10 espécies de vespas capazes de utilizar as bagas de uva como alimento. As espécies predominantes foram Polybia ignobilis e P. minarum, todavia, Synoeca cyanea apresenta maior capacidade de rompimento de bagas íntegras. P. cavapytiformis, P. versicolor e Brachygastra lecheguanatambém foram capazes de abrir a casca dos frutos em bagas anteriormente danificadas.


Assuntos
Vespas , Controle de Pragas , Vitis
20.
Biosci. j. (Online) ; 35(4): 1227-1236, july/aug. 2019. graf, tab
Artigo em Inglês | LILACS | ID: biblio-1048868

RESUMO

In the last decades, the use of entomopathogenic fungi for the control of pest insects has increased globally, however a key step to achieve the successful application of fungal propagules as biocontrol agents depends of various factors, inoculum production being one of the essential stages for these microorganisms to be used in pest management programs. The objective of this study was to evaluate theproduction of conidia by solid fermentation and biphasic culture in different sporulation matrices for four native isolates and a strain of Isaria fumosorosea that have been shown potential for the control of various insects at the laboratory level. The experimental design was completely randomized, two propagation methods were used with six treatments and ten repetitions per treatment; the data were analyzed using an analysis of variance and the means were compared using the Tukey test (p≤ 0.05). In the production by solid fermentation the minimum value of 5.30 × 105 conidia g-1 was registered with the pericarp of peanut and the maximum of 2.35 × 107 conidia g-1 in the corn grain; in the biphasic culture the minimum of 7.60 × 105 conidia g-1 was observed in birdseed and the maximum of 2.07 × 107 conidia g-1 in rice. The differences were significant (p ≤0.05) in the production by method and by substrate, in solid fermentation 6.84 × 106 conidia g-1 and in biphasic culture 8.85 × 106 conidia g-1. In the production by substrate, the rice showed 1.75 × 107 conidia g-1 and the lesser canary seed concentration (7.80 × 105 conidia g-1). The average production per isolate and / or strain was of the order of 106 and significant difference was registered (p ≤ 0.05) among the fungi, the isolate HIB-9 showed concentration in average higher in the production (7.90 × 106 conidia g-1) and the isolated HIB-19 was the least effective, with only 1.08 × 106 conidia g-1. The results obtained show marked differences between the isolates with respect to their capacity to use the different substrates used as propagation media to obtain conidia of I. fumosorosea.


Nas últimas décadas, o uso de fungos entomopatogênicos para o controle de insetos-pragatem aumentado globalmente, porém um passo fundamental para o sucesso da aplicação de propágulos fúngicos como agentes de biocontrole depende de varios fatores, sendo a produção de inóculo um dos estágios essenciais para esses insetos microorganismos a serem usados em programas de controle de pragas. O objetivo deste trabalho foi avaliar a produção de conídios por meio de fermentação sólida e cultura bifásica emdiferentes matrizes de esporulação para quatro isolados nativos e um alinhagem de Isaria fumosorosea que tem demonstrado potencial para o controle de varios insetos em nível laboratorial. O delineamento experimental foi inteiramente casualizado, foram utilizados dois métodos de propagação com seis tratamentos e dezrepetições por tratamento; os dados foraman alisados por meio de análise de variância e as médias comparadas pelo teste de Tukey (p ≤ 0.05). Naprodução por fermentação sólida foi registrado o valor mínimo de 5.30 × 105 conídios g-1 com o pericarpo de amendoim e o máximo de 2.35 × 107 conídios g-1 no grão de milho; na cultura bifásica, o mínimo de 7.60 × 105 conídios g-1 foi observado emsementes de aves e o máximo de 2.07 × 107conídios g-1em arroz. As diferençasforam significativas (p ≤ 0.05) na produção pelo método e pelo substrato, na fermentação sólida 6.84 × 106 conídios g-1 e na cultura bifásica 8.85 × 106 conídios g-1. Naprodução por substrato, o arroz apresentou 1.75 × 107conídios g-1 e a menor concentração de sementes de canário (7.80 × 105conídios g-1). A produção média por isolado e / ou cepa foi da ordem de 106 e registrou-se diferença significativa (p ≤ 0.05) entre os fungos, o isolado HIB-9 apresentou concentração em média maior na produção (7.90 × 106conídios g-1) e o isolado HIB-19 foi o menos efetivo, com apenas 1.08 × 106 conídios g-1. Os resultados obtidos mostram diferenças marcantes entre os isolados quanto à capacidade de utilização dos diferentes substratos utilizados como meio de propagação para obtenção de conídios de I. fumosorosea.


Assuntos
Esporos Fúngicos , Controle de Pragas , Controle Biológico de Vetores , Fungos
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