Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Entomol ; 49(4): 876-885, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32623469

RESUMO

A number of soybean varieties traditionally bred for resistance to various soybean arthropod pests have been identified as resistant to Megacopta cribraria (F.) (Hemiptera: Plataspidae). However, the mechanisms of host-plant resistance (HPR) in this system are not understood. The goal of this study was to identify the mechanisms of resistance by examining the role of plant volatile organic compounds (VOCs) and free amino acids (FAAs) among 16 soybean varieties. Choice and no-choice cage experiments identified several soybean varieties that demonstrated antixenosis as well as antibiosis. However, resistance varied over time in certain soybean varieties, such as N02-7002 and PI567352B. Mean nymph number from choice experiments had positive correlations with the FAAs asparagine, tryptophan, alanine, phenylanaline, and serine; negative correlation with leucine and threonine. Four plant volatiles, hexanal, 2-pentylfuran, beta-cyclocitral, and cis-9-hexadecenal, were positively correlated with subsequent nymph development, whereas n-hexadecenoic acid was negatively correlated with nymph number only, in adult choice cage experiments. This study contributes to understanding the mechanisms of HPR through associations with plant VOCs and FAAs in relation to M. cribraria development and provides useful knowledge for developing soybean varieties for M. cribraria management.


Assuntos
Fabaceae , Hemípteros , Heterópteros , Compostos Orgânicos Voláteis , Animais , Ninfa , Glycine max
2.
Environ Entomol ; 49(1): 88-97, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31904078

RESUMO

Megacopta cribraria (F.) (Hemiptera: Plataspidae) is an invasive pest of soybean that has spread across the southeastern United States since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and host plant resistance (HPR) among soybean varieties, although the specific mechanisms of HPR remain unknown. The objectives of this study were, therefore, to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC); and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety 'Camp' was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and should be managed by incorporating integrated pest management tactics, such as HPR, that help conserve natural enemy populations.


Assuntos
Glycine max , Heterópteros , Animais , Georgia , North Carolina , Ninfa , South Carolina , Tricomas
3.
Health Promot Chronic Dis Prev Can ; 36(6): 101-11, 2016 Jun.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-27284702

RESUMO

INTRODUCTION: The Public Health Agency of Canada's Multi-sectoral Partnerships Initiative, administered by the Centre for Chronic Disease Prevention (CCDP), brings together diverse partners to design, implement and advance innovative approaches for improving population health. This article describes the development and initial priorities of an action research project (a learning and improvement strategy) that aims to facilitate continuous improvement of the CCDP's partnership initiative and contribute to the evidence on multi-sectoral partnerships. METHODS: The learning and improvement strategy for the CCDP's multi-sectoral partnership initiative was informed by (1) consultations with CCDP staff and senior management, and (2) a review of conceptual frameworks to do with multi-sectoral partnerships. Consultations explored the development of the multi-sectoral initiative, barriers and facilitators to success, and markers of effectiveness. Published and grey literature was reviewed using a systematic search strategy with findings synthesized using a narrative approach. RESULTS: Consultations and the review highlighted the importance of understanding partnership impacts, developing a shared vision, implementing a shared measurement system and creating opportunities for knowledge exchange. With that in mind, we propose a six-component learning and improvement strategy that involves (1) prioritizing learning needs, (2) mapping needs to evidence, (3) using relevant data collection methods, (4) analyzing and synthesizing data, (5) feeding data back to CCDP staff and teams and (6) taking action. Initial learning needs include investigating partnership reach and the unanticipated effects of multi-sectoral partnerships for individuals, groups, organizations or communities. CONCLUSION: While the CCDP is the primary audience for the learning and improvement strategy, it may prove useful for a range of audiences, including other government departments and external organizations interested in capturing and sharing new knowledge generated from multi-sectoral partnerships.


INTRODUCTION: L'initiative Partenariats plurisectoriels de l'Agence de la santé publique du Canada, gérée par le Centre de prévention et de contrôle des maladies chroniques (CPCMC), réunit différents partenaires en vue de concevoir, de mettre en oeuvre et de faire progresser des approches novatrices visant à améliorer la santé de la population. Cet article décrit l'évolution et les premières priorités d'un projet de recherche-action (stratégie d'apprentissage et d'amélioration) dont l'objectif est de faciliter l'amélioration continue de l'initiative de partenariat du CPCMC et de contribuer aux données probantes sur les partenariats plurisectoriels. MÉTHODOLOGIE: La stratégie d'apprentissage et d'amélioration du CPCMC pour les partenariats plurisectoriels repose sur les consultations avec le personnel et la haute direction du CPCMC et sur l'examen de cadres conceptuels liés aux partenariats plurisectoriels. Les consultations ont porté sur l'élaboration de l'initiative plurisectorielle, ses obstacles, ses facteurs de réussite et ses indicateurs d'efficacité. Nous avons fait une revue de littérature et consulté la littérature grise en appliquant une stratégie de recherche systématique puis nous avons résumé nos conclusions sous forme de comptes rendus. RÉSULTATS: Les consultations et l'examen de la littérature ont souligné l'importance de comprendre l'incidence des partenariats, d'élaborer une vision commune, de mettre en oeuvre un système partagé de mesures et de créer des occasions d'échange de connaissances. C'est dans cette perspective que nous proposons une stratégie d'apprentissage et d'amélioration en six volets : 1) donner la priorité aux besoins en matière d'apprentissage, 2) relier les besoins aux données probantes, 3) utiliser des méthodes de collecte de données pertinentes, 4) analyser et synthétiser ces données, 5) fournir une rétroaction aux membres et aux équipes du CPCMC et 6) agir. Les premiers besoins en matière d'apprentissage concernent la portée des partenariats et les répercussions non anticipées des partenariats plurisectoriels sur les individus, les équipes, les organismes et les communautés. CONCLUSION: Bien que principalement destinée au CPCMC, la stratégie d'apprentissage et d'amélioration pourrait s'avérer tout aussi pertinente pour d'autres publics, notamment d'autres ministères ou organismes externes intéressées à saisir et partager de nouvelles connaissances sur les partenariats plurisectoriels.


Assuntos
Atenção à Saúde , Pesquisa sobre Serviços de Saúde , Saúde Pública , Parcerias Público-Privadas , Canadá , Humanos
4.
J Invertebr Pathol ; 127: 35-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25731127

RESUMO

Megacopta cribraria (Hemiptera: Plataspidae) has become a pest of soybean, Glycine max (L.), in the United States. While several natural enemies of M. cribraria have been reported, our study is the first to report nematodes beneath the pleural membranes in the abdominal cavities of adults. Morphological and molecular analyses suggest this nematode belongs to the family Mermithidae. This first report of a nematode infection in M. cribraria adds to the current inventory of enemies attacking this insect. Our observations provide a basis for future research to examine the impact of nematodes on M. cribraria mortality and to investigate their capacity to reduce populations.


Assuntos
Heterópteros/parasitologia , Animais , Genes de Helmintos , Mermithoidea , Estados Unidos
5.
Mar Pollut Bull ; 88(1-2): 129-37, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25287226

RESUMO

The seafloor at an open ocean finfish aquaculture facility in the western Gulf of Maine, USA was monitored from 1999 to 2008 by sampling sites inside a predicted impact area modeled by oceanographic conditions and fecal and food settling characteristics, and nearby reference sites. Univariate and multivariate analyses of benthic community measures from box core samples indicated minimal or no significant differences between impact and reference areas. These findings resulted in development of an adaptive monitoring protocol involving initial low-cost methods that required more intensive and costly efforts only when negative impacts were initially indicated. The continued growth of marine aquaculture is dependent on further development of farming methods that minimize negative environmental impacts, as well as effective monitoring protocols. Adaptive monitoring protocols, such as the one described herein, coupled with mathematical modeling approaches, have the potential to provide effective protection of the environment while minimize monitoring effort and costs.


Assuntos
Aquicultura , Meio Ambiente , Monitoramento Ambiental/métodos , Animais , Oceano Atlântico , Custos e Análise de Custo , Monitoramento Ambiental/economia , Peixes , Maine , Modelos Teóricos , Análise Multivariada , Oceanografia
6.
Environ Entomol ; 39(3): 956-69, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20550811

RESUMO

Grid sampling (one sample per 0.40 ha) in 12 cotton (Gossypium hirsutum L.) fields for stink bugs and boll injury caused by stink bug feeding was conducted in 2007 and 2008 in South Carolina and Georgia. The main species collected using the beat cloth method were the green stink bug, Acrosternum hilare (Say) (69%); brown stink bug, Euschistus servus (Say) (18%); and the southern green stink bug, Nezara viridula (L.) (14%), respectively. The inverted distance weighted interpolation method and Spatial Analysis by Distance IndicEs analyses showed spatial variability in both boll injury and stink bug densities. Four of five fields with field-average boll injury exceeding 15% had a combination of either soybean or peanut adjacent to the cotton field of interest. The Spatial Analysis by Distance IndicEs index of dispersion for stink bug densities and boll injury averaged over the season indicated significant aggregation at the 5% error rate in only one and four analyses (combinations of fields, species, and life stages) of a total of 54 in 2007 and 2008, respectively. By sampling date, overall indices of dispersion for boll injury data indicated significant aggregation in four of the 63 date-field combinations at the 5% error rate. Across years, overall indices of spatial association between boll injury and stink bug densities were significant in 17 of 69 analyses, with positive associations detected in seven of 12 fields; these data suggest that spatial distribution of stink bugs in cotton fields does not always coincide with boll injury.


Assuntos
Gossypium/parasitologia , Heterópteros/fisiologia , Interações Hospedeiro-Parasita , Animais , Georgia , Densidade Demográfica , Dinâmica Populacional , South Carolina
7.
J Econ Entomol ; 103(2): 525-32, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20429470

RESUMO

Cotton, Gossypium hirsutum L., bolls were sampled in commercial fields for stink bug (Hemiptera: Pentatomidae) injury during 2007 and 2008 in South Carolina and Georgia. Across both years of this study, boll-injury percentages averaged 14.8 +/- 0.3 (SEM). At average boll injury treatment levels of 10, 20, 30, and 50%, the percentage of samples with at least one injured boll was 82, 97, 100, and 100%, respectively. Percentage of field-sampling date combinations with average injury < 10, 20, 30, and 50% was 35, 80, 95, and 99%, respectively. At the average of 14.8% boll injury or 2.9 injured bolls per 20-boll sample, 112 samples at Dx = 0.1 (within 10% of the mean) were required for population estimation, compared with only 15 samples at Dx = 0.3. Using a sample size of 20 bolls, our study indicated that, at the 10% threshold and alpha = beta = 0.2 (with 80% confidence), control was not needed when <1.03 bolls were injured. The sampling plan required continued sampling for a range of 1.03-3.8 injured bolls per 20-boll sample. Only when injury was > 3.8 injured bolls per 20-boll sample was a control measure needed. Sequential sampling plans were also determined for thresholds of 20, 30, and 50% injured bolls. Sample sizes for sequential sampling plans were significantly reduced when compared with a fixed sampling plan (n=10) for all thresholds and error rates.


Assuntos
Gossypium/parasitologia , Hemípteros/fisiologia , Projetos de Pesquisa , Animais , Controle de Insetos , Dinâmica Populacional
8.
Environ Entomol ; 39(5): 1420-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22546436

RESUMO

The distribution of phytophagous stink bugs and associated boll injury in margins of cotton fields bordering various agronomic crops and woodlands were studied in 2007 and 2008. Two commercial cotton fields, ranging in size from 7.8 to 12.1 ha in Barnwell and Lee Counties, SC, were sampled weekly each year along predetermined transects at 0, 5, 10, and 25 m from the outside margin into the cotton field. Stink bugs were sampled using a ground cloth (0.91 by 0.91 m), and quarter-sized bolls (≈ 2.5 cm in diameter) were collected and examined for internal damage. Density (bugs/row-m) of total stink bugs (adults plus nymphs) was greatest in cotton adjacent to peanut. Boll injury was significantly greater in cotton adjacent to soybean and peanut than in cotton next to other habitats, including corn, cotton, and woodlands, during midseason. Density of nymphs was greatest in cotton adjacent to peanut during mid and late season. Densities of total stink bugs and adults were greatest in cotton immediately adjacent (0 m) to all bordering crops and decreased as distance from the margin increased. Boll injury was greatest in cotton immediately adjacent (0 m) to the bordering crop in mid and late season. Because densities of stink bugs and boll injury vary spatially and temporally along field margins of cotton and can vary significantly based on the adjacent crop, such factors should be considered when developing integrated pest management strategies in cotton.


Assuntos
Gossypium , Heterópteros/fisiologia , Animais , Produtos Agrícolas , Meio Ambiente , Preferências Alimentares , Heterópteros/crescimento & desenvolvimento , Controle de Insetos , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , South Carolina
9.
Environ Entomol ; 38(2): 450-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19389295

RESUMO

Early-season soybean, Glycine max L. Merrill, was evaluated in Arkansas soybean fields as a trap crop for a complex of stink bug species that included Nezara viridula L., Acrosternum hilare (Say), and Euschistus servus (Say). Early-season soybean production systems (ESPSs) are composed of indeterminate soybean cultivars planted in April. In the first year of a 2-yr study, field-scale trap crops ( approximately 0.5-1.0 ha) of maturity group (MG) III and IV soybean were planted adjacent to production fields of MG V soybean. Stink bugs were attracted first to the ESPS trap crops and were twice treated with insecticide, yet damaging populations developed later in the MG V soybean adjacent to the trap crops. General sampling and observations of low stink bug densities in commercial fields of soybean and corn across the study area suggested that stink bugs were widely distributed across the agricultural landscape. These observations and the subsequent discovery of additional ESPS fields outside the study area suggested that developing populations in the adjacent MG V soybean probably did not originate from the trap crops. However the source of the populations colonizing MG V soybean could not be determined, and we concluded that the scale of future experiments should be increased to better control stink bugs dispersing from other ESPSs outside the study area. In the second year of the study, the experiment was expanded in size to a farm- or community-scale project where entire fields of ESPSs (8-32 ha) were used as trap crops. Insecticide was applied to the trap-crop fields and other fields of ESPSs within a 0.8-km radius of targeted response fields, yet again there was no apparent effect on subsequent populations of stink bugs in the MG V response fields. With the recent expansion of ESPSs in Arkansas, it may be difficult to use ESPSs as a trap crop to lower stink bug populations across large enough areas to suppress populations in late-season soybean. Also, multiple soybean cultivars are generally planted across a 2- or 3-mo period in Arkansas, which results in staggered soybean development across the landscape and extends the time period that soybean is attractive to colonizing stink bugs. Trap crops of ESPSs are only attractive for oviposition for up to 4-5 wk and cannot protect full-season soybean production systems (FSSPSs) for such an extended time period. This shift in production systems may limit the use of ESPS trap crops for management of stink bugs unless highly coordinated efforts are made to synchronize soybean maturity and control stink bugs in ESPSs across large geographic areas.


Assuntos
Glycine max , Heterópteros , Controle de Insetos/métodos , Estações do Ano , Agricultura/métodos , Animais , Arkansas , Inseticidas , Densidade Demográfica , Fatores de Tempo
10.
J Econ Entomol ; 102(1): 229-36, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19253641

RESUMO

From 2003 through 2007, densities of stink bugs were monitored weekly in 297 commercial production fields of early and late soybean, Glycine max L. Merrill, in southeast and southwest Arkansas. The goal of this research was to better understand seasonal abundance, species composition, and population dynamics of pentatomids as a benchmark reference for future management systems. Thirty-five percent of all the 25-sweep samples taken in soybean contained at least one stink bug specimen. The average density (mean +/- SEM) of stink bugs across all soybean samples was 1.84 +/- 0.06 per 25 sweeps. Overall, Nezara viridula L. was the most abundant species, although Euschistus serous (Say) was frequently found in soybean samples (18% of all samples). Peak densities of stink bugs in soybean were observed during the full-pod (R7) developmental stage. Approximately 25% of all soybean fields sampled had threshold densities (nine or more per 25 sweeps) at some time during the year, although 82 and 78% of fields in 2006 and 2007, respectively, reached threshold. At low densities (one to three stink bugs per 25 sweeps), E. serous comprised 50% of total stink bugs, but at high densities (> 71 stink bugs per 25 sweeps), N. viridula comprised 81% of total stink bugs. Piezodorus guildinii (Westwood) was observed as a pest of Arkansas soybean in 2005, and reproduction in soybean was documented in 2006 and 2007. Stink bugs seem to be a serious and increasingly important pest of soybean in southern Arkansas. Crop phenological development is a key factor in predicting colonization and population growth of stink bugs on Arkansas soybean, regardless of geographic region or type of soybean production system.


Assuntos
Glycine max/parasitologia , Heterópteros , Estações do Ano , Animais , Arkansas , Biodiversidade , Dinâmica Populacional
11.
J Econ Entomol ; 102(6): 2360-70, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20069868

RESUMO

Stink bugs (Hemiptera: Pentatomidae) were sampled in commercial cotton, Gossypium hirsutum L., fields in 2007 and 2008 in South Carolina and Georgia. The main species collected with the beat cloth and sweep net methods were green stink bug, Acrosternum hilare (Say) (63 and 57%, respectively); brown stink bug, Euschistus servus (Say) (23 and 18%, respectively); and southern green stink bug, Nezara viridula (L.) (14 and 22%, respectively). Average stink bug densities were 0.145 +/- 0.010 (mean +/- SEM) for adults and 0.250 +/- 0.027 for nymphs per 3.7 m of row by using the beat cloth method. Average stink bug densities were 0.291 +/- 0.016 for all adults and 0.137 +/- 0.018 for all nymphs per 50 sweeps. A density of two southern green stink bugs per 3.7 m of row by using the beat cloth method required 43 samples (reliability or precision, Dx = 0.3) for population estimation, whereas 88 samples were necessary for a density of two southern green stink bugs per 50 sweeps. At low densities, the sweep net was a more cost-reliable sampling method for all species and life stages. For adult stink bugs, the beat cloth method became more reliable at densities of 1.0, 3.2, and 5.8 stink bugs per 3.7 m of cotton row for southern green stink bug, brown stink bug, and green stink bug, respectively. Sequential sampling consistently reduced sample size for all insects compared with a fixed sampling plan.


Assuntos
Gossypium/parasitologia , Heterópteros , Controle de Insetos , Animais , Georgia , Ninfa , Densidade Demográfica , South Carolina
12.
J Econ Entomol ; 94(2): 403-9, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11332832

RESUMO

The green stink bug, Acrosternum hilare (Say), the southern green stink bug, Nezara viridula (L), and the brown stink bug, Euschistus servus (Say), were predominant phytophagous Pentatomidae detected during 1995-1997 in cotton in South Carolina. These species occurred in similar numbers in conventional and transgenic cotton 'NuCOTN33B', containing the gene for expression of CryIA(c) delta-endotoxin of Bacillus thuringiensis Berliner variety kurstaki. Adult stink bugs moved into cotton from wild and cultivated alternate hosts during July, and reproducing populations usually were detected in cotton from late July into September. Applications of either methyl parathion (0.56 kg [AI]/ha) directed for stink bugs or lambda-cyhalothrin (0.037 kg [AI]/ha) or cyfluthrin (0.056 kg [AI]/ha) for control of cotton bollworm, Helicoverpa zea (Boddie), provided effective control of pentatomids in NuCOTN33B or conventional 'DP5415' and increased yields compared with untreated plots. Fiber quality did not differ among treated or untreated plots of NuCOTN33B. The ground-cloth technique was used to estimate populations of stink bugs, and data indicated that treatment at one bug per 2 m of row adequately protected cotton from yield loss due to stink bug damage. Observations on boll damage indicated that treatment might be necessary if >20-25% reveal internal symptoms of feeding injury during mid- to late season. More detailed damage thresholds should be developed to complement an approach based on population monitoring. This study validated current recommendations for management of pentatomids in cotton, demonstrated the necessity of threshold use for stink bugs in transgenic cultivars expressing endotoxin from B. thuringiensis, and provided insight into further development of management options for pentatomids in the crop.


Assuntos
Gossypium , Hemípteros , Controle de Insetos , Animais , Controle de Insetos/métodos , Inseticidas , Metil Paration , Nitrilas , Piretrinas
13.
J Health Care Finance ; 28(2): 50-64, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11794757

RESUMO

For the future survival of the rural hospitals in the U.S., there is a need to make sound financial decisions. The Activity Based Cost Accounting (ABC) provides more accurate and detailed cost information to make an informed capital investment decision taking into consideration all the costs and revenue reimbursement from third party payors. The paper analyzes, evaluates and compares two scenarios of acquiring capital equipment and attempts to show the importance of utilizing the ABC method in making a sound financial decision as compared to the traditional cost method.


Assuntos
Gastos de Capital , Alocação de Custos , Administração Financeira de Hospitais/métodos , Hospitais Rurais/economia , Investimentos em Saúde/economia , Tomada de Decisões Gerenciais , Reembolso de Seguro de Saúde , Serviço Hospitalar de Compras/economia , Ultrassonografia/economia , Ultrassonografia/instrumentação , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...