Términos relacionados

143 resultados encontrados para: AUTOR: Williams, Trevor
  • «
  • 1 de 15
  • »
1.
Artículo
Comparación de Novaluron, Piriproxifeno, Spinosad y Temefos como larvicidas contra Aedes aegypti en Chiapas, México
Marina Fernández, Carlos Félix (autor) ; Bond Compeán, Juan Guillermo (autor) ; Muñoz, José (autor) ; Valle Mora, Javier Francisco (autor) ; Quiroz Martínez, Humberto (autor) ; Torres Monzón, Jorge Aurelio (autor) ; Williams, Trevor (autor) ;
Disponible en línea
Contenido en: Salud Pública de México Volumen 62, número 4 (julio-agosto de 2020), p. 424-431 ISSN: 0036-3634
PDF
Resumen en: Español | Inglés |
Resumen en español

Objetivo. Comparar la eficacia de tres larvicidas modernos para el control de Aedes aegypti en tanques de agua doméstica en Chiapas. Material y métodos. Se comparó la eficacia de piriproxifeno, novalurón, dos formulaciones de spinosad (gránulos y tabletas) y temefos en ovitrampas y tanques domésticos de agua. Resultados. El piriproxifeno y el temefos proporcionaron de 2 a 3 semanas de control de larvas en ovitrampas, mientras que los gránulos de spinosad y novaluron proporcionaron de 7 a12 semanas. Los tanques de agua tratados produjeron una reducción significativa en la oviposición por Ae. aegypti en las casas (p<0.001). Se encontró gran cantidad de larvas en los tanques tratados con temefos y piriproxifeno en comparación con los tratados con novaluron y tabletas de spinosad durante la mayor parte del estudio. Conclusión. Las formulaciones de spinosad en tabletas y novaluron fueron larvicidas efectivos en esta región. El bajo desempeño de temefos puede indicar una susceptibilidad reducida en poblaciones de Ae. aegypti en Chiapas.

Resumen en inglés

Objective. To compare the efficacy of three modern larvicides with the organophosphate temephos for control of Aedes aegypti in water tanks in Chiapas. Materials and methods. Trials were performed to compare the efficacy of pyriproxyfen, novaluron, two formulations of spinosad (granules and tablets) and temephos in oviposition traps and domestic water tanks. Results. Pyriproxyfen and temephos provided 2-3 weeks of complete control of larvae in oviposition traps, whereas spinosad granules and novaluron provided 7-12 weeks of control. Treatment of water tanks resulted in a significant reduction in oviposition by Ae. aegypti in houses (p<0.001). Higher numbers of larvae were present in temephos and pyriproxyfen-treated water tanks compared to novaluron and spinosad tablet treatments during most of the study. Conclusion. Spinosad formulations and novaluron were effective larvicides in this region. The poor performance of temephos may be indicative of reduced susceptibility in Ae. aegypti populations in Chiapas.


PDF PDF
Resumen en: Inglés |
Resumen en inglés

The sterile insect technique (SIT) may offer a means to control the transmission of mosquito borne diseases. SIT involves the release of male insects that have been sterilized by exposure to ionizing radiation. We determined the effects of different doses of radiation on the survival and reproductive capacity of local strains of Aedes aegypti and Ae. albopictus in southern Mexico. The survival of irradiated pupae was invariably greater than 90% and did not differ significantly in either sex for either species. Irradiation had no significant adverse effects on the flight ability (capacity to fly out of a test device) of male mosquitoes, which consistently exceeded 91% in Ae. aegypti and 96% in Ae. albopictus. The average number of eggs laid per female was significantly reduced in Ae. aegypti at doses of 15 and 30 Gy and no eggs were laid by females that had been exposed to 50 Gy. Similarly, in Ae. albopictus, egg production was reduced at doses of 15 and 25 Gy and was eliminated at 35 Gy. In Ae. aegypti, fertility in males was eliminated at 70 Gy and was eliminated at 30 Gy in females, whereas in Ae. albopictus, the fertility of males that mated with untreated females was almost zero (0.1%) in the 50 Gy treatment and female fertility was eliminated at 35 Gy. Irradiation treatments resulted in reduced ovary length and fewer follicles in both species. The adult median survival time of both species was reduced by irradiation in a dose-dependent manner. However, sterilizing doses of 35 Gy and 50 Gy resulted in little reduction in survival times of males of Ae. albopictus and Ae. aegypti, respectively, indicating that these doses should be suitable for future evaluations of SIT-based control of these species. The results of the present study will be applied to studies of male sexual competitiveness and to stepwise evaluations of the sterile insect technique for population suppression of these vectors in Mexico.


3.
Artículo
*Solicítelo con su bibliotecario/a
Efficacy of larvicides for the control of dengue, Zika, and chikungunya vectors in an urban cemetery in southern Mexico
Marina Fernández, Carlos Félix ; Bond Compeán, Juan Guillermo (coaut.) ; Muñoz, José (coaut.) ; Valle Mora, Javier Francisco (coaut.) ; Quiroz Martínez, Humberto (coaut.) ; Torres Monzón, Jorge Aurelio (coaut.) ; Williams, Trevor (coaut.) ;
Contenido en: Parasitology Research Vol. 117, no. 6 (June 2018), p. 1941–1952 ISSN: 0932-0113
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Many countries in Latin America have recently experienced outbreaks of Zika and chikungunya fever, in additional to the usual burden imposed by dengue, all of which are transmitted by Aedes aegypti in this region. To identify potential larvicides, we determined the toxicity of eight modern insecticides to A. aegypti larvae from a colony that originated from field-collected insects in southern Mexico. The most toxic compounds were pyriproxyfen (which prevented adult emergence) and λ-cyhalothrin, followed by spinetoram, imidacloprid, thiamethoxam, and acetamiprid, with chlorantraniliprole and spiromesifen the least toxic products. Field trails performed in an urban cemetery during a chikungunya epidemic revealed that insecticide-treated ovitraps were completely protected from the presence of Aedes larvae and pupae for 6 and 7 weeks in spinosad (Natular G30) and λ- cyhalothrin-treated traps in both seasons, respectively, compared to 5–6 weeks for temephos granule-treated ovitraps, but was variable for pyriproxyfen-treated ovitraps with and 1 and 5 weeks of absolute control in the dry and rainy seasons, respectively. Insecticide treatments influenced the mean numbers of Aedes larvae + pupae in each ovitrap, mean numbers of eggs laid, and percentage of egg hatch over time in both trials. The dominant species was A. aegypti in both seasons, although the invasive vector Aedes albopictus was more prevalent in the rainy season (26.7%) compared to the dry season (10.2%).We conclude that the granular formulation of spinosad (Natular G30) and a suspension concentrate formulation of λ-cyhalothrin proved highly effective against Aedes spp. in both the dry and rainy seasons in the cemetery habitat in this region.


4.
- Artículo con arbitraje
PDF PDF
Resumen en: Inglés |
Resumen en inglés

Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis using the sterile insect technique (SIT). Larval diet is a major factor in mass-rearing for SIT programs. We compared dietary effects on immature development and adult fitness-related characteristics for an International Atomic Energy Agency (IAEA) diet, developed for rearing Ae. albopictus, and a standardized laboratory rodent diet (LRD), under a 14:10 h (light:dark) photoperiod ("light" treatment) or continuous darkness during larval rearing. Larval development was generally fastest in the IAEA diet, likely reflecting the high protein and lipid content of this diet. The proportion of larvae that survived to pupation or to adult emergence did not differ significantly between diets or light treatments. Insects from the LRD-dark treatment produced the highest proportion of male pupae (93% at 24 h after the beginning of pupation) whereas adult sex ratio from the IAEA diet tended to be more male-biased than that of the LRD diet. Adult longevity did not differ significantly with larval diet or light conditions, irrespective of sex. In other aspects the LRD diet generally performed best. Adult males from the LRD diet were significantly larger than those from the IAEA diet, irrespective of light treatment. Females from the LRD diet had ~25% higher fecundity and ~8% higher egg fertility compared to those from the IAEA diet. Adult flight ability did not differ between larval diets, and males had a similar number of copulations with wild females, irrespective of larval diet. The LRD diet had lower protein and fat content but a higher carbohydrate and energetic content than the IAEA diet. We conclude that the LRD diet is a low-cost standardized diet that is likely to be suitable for mass-rearing of Ae. aegypti for area-wide SIT-based vector control.


5.
- Capítulo de libro con arbitraje
*Solicítelo con su bibliotecario/a
Pasado, presente y perspectivas del control biológico en México
Rodríguez del Bosque, Luis Ángel (autor) ; Arredondo Bernal, Hugo César (autor) ; Williams, Trevor (autor) ; Barrera, Juan F. (autor) ;
Disponible en línea
Contenido en: Casos de control biológico en México, volumen 2 / editores: Hugo César Arredondo Bernal, Luis Ángel Rodríguez del Bosque Distrito Federal, México : Biblioteca Básica de Agricultura : Editorial del Colegio de Postgraduados : Colegio de Postgraduados : Fundación Colegio de Postgraduados en Ciencias Agrícolas : Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria : Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias : Universidad Autónoma Chapingo, 2015 Vol. 2, p. 17-28 ISBN:978-607-7152-58-3
Bibliotecas: Tapachula
Cerrar
SIBE Tapachula
29630-30 (Disponible)
Disponibles para prestamo: 1
Nota: Solicítelo con su bibliotecario/a
Resumen en español

Se presenta una síntesis histórica del control biológico en México como disciplina científica y estrategia de combate de plagas agrícolas. Aunque las acciones de control biológico en México datan desde hace más de un siglo, el estudio y aplicación de esta disciplina en nuestro país ha incrementado notablemente durante las últimas dos décadas. El renovado interés por el control biológico en México es producto de diversos factores, entre ellos la fundación de la Sociedad Mexicana de Control Biológico en 1989; el apoyo gubernamental para la investigación y becas de posgrado en esta disciplina; y a la labor de numerosas instituciones y organismos como el Centro Nacional de Referencia en Control Biológico, así como los centros de investigación y de enseñanza superior de nuestro país, que han intensificado los estudios y transferencia de tecnología sobre control biológico durante los últimos años. Se analiza la situación actual y las perspectivas del control biológico de plagas en México.

Resumen en inglés

We present a brief history of biological control as a scientific area of study and a method for controlling insect pests in Mexico. Although biological control activities in Mexico started nearly a century ago, the study and application of biological control has greatly increased during the last 20 years. The renewed interest in biological control in Mexico is the result of several factors, including the founding of the Mexican Society of Biological Control in 1989; government funding of research projects and graduate scholarships in this area; and research and technology transfer activities by the Centro Nacional de Referencia en Control Biológico, research institutions and universities in Mexico. The current activities and perspectives for biological control in Mexico are analyzed.


6.
- Artículo con arbitraje
PDF PDF
Resumen en: Español | Inglés |
Resumen en español

La capacidad infectiva de los juveniles infectivos (JIs) del nemátodo H. bacteriophora (Poinar) fue evaluada contra larvas de tercer estadio de Anastrepha ludens (Loew) (Diptera: Tephritidae), bajo condiciones de laboratorio, utilizando suelo con textura areno-arcillosa con diferentes porcentajes de humedad. El estudio consistió de tres experimentos, donde se midió la efectividad de los juveniles infectivos (JIs): 1) probando seis diferentes niveles de humedad en el suelo; 2) en suelo con pérdida constante de humedad, durante 15 días; y 3) en suelo con 16% de humedad inicial y rehidratación cada cinco días. En el primer experimento se observó la mayor infección en suelo con 18% de humedad (-63.1 bars), aunque esta mortalidad no fue significativamente mayor a 21% de humedad (-20.4 bars). Con un suelo a 24% de humedad (-7.70 bars), el porcentaje de mortalidad de A. ludens disminuyó a cerca de 50%. De la misma forma, la mortalidad larval disminuyó significativamente en suelos con 15% y 12% de humedad (-240.1 y -1,232 bars, respectivamente), decreciendo aún más (16% de mortalidad) a 9% de humedad (-10,147 bars). En el segundo experimento se observó que a medida que la humedad del suelo decreció desde 16% hasta menos del 10% durante un período de 15 días, la infectividad de los JIs, expresada en mortalidad larval de A. ludens, disminuyó progresivamente desde más del 55% hasta menos del 10%. En el tercer experimento, la reposición periódica de la humedad permitió incrementar el período de infectividad de los JIs hasta los 21 días post-aplicación, pero después la infectividad de los JIs también fue disminuyendo. En conclusión, la humedad del suelo es un factor importante que debe ser considerado para mantener la infectividad de los JIs de H. bacteriophora como agentes de control biológico de dicha plaga.

Resumen en inglés

The efficacy of Heterorhabditis bacteriophora (Poinar) infective juveniles (IJs) was evaluated against third instar Anastrepha ludens (Loew) (Diptera: Tephritidae) under laboratory conditions in a sandy clay soil at various levels of soil moisture. Three experiments were performed in which the efficacy of the IJs against A. ludens was estimated, i.e., (a) at 6 different levels of soil moisture, (b) in soil that was allowed to lose moisture over a 15 day period, and (c) in soil with an initial moisture content of 16% and in which moisture loss was partially mitigated by adding water at 5-day intervals. In the first experiment, the greatest A. ludens mortality (80%) was observed in soil with 18% moisture (-63.1 bars), although this was not significantly greater than A. ludens mortality at 21% moisture (-20.4 bars). At 24% soil moisture (-7.70 bars), percentage of mortality of A. ludens declined to about 50%. Likewise insect mortality was substantially lower at soil moisture levels of 15% (-240.1 bars) and 12% (-1,232 bars) and very much lower (about 16%) at 9% soil moisture (-10,147 bars). In the second experiment, as soil moisture declined from 16% to less than 10% over a 15 day period, the infectivity of IJs, as indicated by A. ludens larval mortality, progressively declined from more than 55% to less than 10%. In the third experiment, in which moisture loss was partially mitigated by adding water at 5-day intervals, the decline in infectivity of IJs was gradual up to 21 days, but decreased thereafter. We conclude that soil moisture levels must be carefully considered when applying H. bacteriophora IJs to control A. ludens under field conditions, because soil moisture has a marked effect on the efficacy of IJs for the biological control of this pest.


7.
- Artículo con arbitraje
PDF PDF
Resumen en: Inglés |
Resumen en inglés

The larvicidal efficacy of the naturally derived insecticide spinosad, for control of immature stages of Anopheles albimanus and associated culicids, was compared to that of synthetic and biological larvicides. Effects on non-target insects were also determined. Methods: A field trial was performed in replicated temporary pools during the rainy season, in southern Mexico. Pools were treated with 10 ppm a.i. spinosad (Tracer 480SC), Bti granules applied at 2 kg/ha (VectoBac WDG, ABG-6511), and 100 ml/ha temephos (50 EC), or an untreated control. Numbers of immature mosquitoes, and aquatic insects in pools were monitored for 20 weeks. Results: Samples of immature mosquitoes comprised approximately 10% An. albimanus , 70% Culex spp. (mostly Cx. melanoconion and Cx. coronator ) and 20% Uranotaenia lowii . The most effective larvicides were spinosad and temephos that eliminated An. albimanus in 16 out of 20 post-treatment samples, or 9 weeks of continuous control of immature stages, respectively. These larvicides resulted in 15 and 5 weeks of elimination of Culex spp., respectively, or 20 and 4 weeks of continuous elimination of U. lowii , respectively. Bti treatment provided little consistent control. Aquatic insects were recorded comprising 3 orders, 20 families, 40 genera and 44 species. Shannon diversity index values (H?) for aquatic insects were highest in the control (0.997) and Bti (0.974) treatments, intermediate in the spinosad treatment (0.638) and lowest in the temephos treatment (0.520). Severely affected non-target insects in the spinosad and temephos treated pools were predatory Coleoptera, Hemiptera and Odonata, which in the case of spinosad was likely due to the high concentration applied. Bti had little effect on aquatic insects.

The spinosad treatment retained larvicidal activity for markedly longer than expected. Spinosad is likely to be an effective tool for control of anopheline and other pool-breeding mosquitoes in tropical regions. Non-target effects of spinosad on aquatic insects merit further study, but were likely related to the concentration of the product used.


8.
Capítulo de libro - Memoria en extenso
*Solicítelo con su bibliotecario/a
Análisis de problemas ocasionados por plagas del café bajo un enfoque holístico
Barrera, Juan F. ; Gómez Ruiz, Jaime (coaut.) ; Parra Vázquez, Manuel Roberto (coaut.) ; Mercado Vidal, Gabriel (coaut.) ; Williams, Trevor (coaut.) ;
Contenido en: Entomología Mexicana 2013 México : Sociedad Mexicana de Entomología, c2013 Vol. 12, Tomo II, p. 1128- 1133 ISBN:978-607-7151-09-8
Nota: Solicítelo con su bibliotecario/a

9.
- Artículo con arbitraje
Spinosad: a biorational mosquito larvicide for use in car tires in southern Mexico
Marina Fernández, Carlos Félix ; Bond Compeán, Juan Guillermo (coaut.) ; Muñoz, José (coaut.) ; Valle Mora, Javier Francisco (coaut.) ; Chirino, Nelva (coaut.) ; Williams, Trevor (coaut.) ;
Contenido en: Parasites and Vectors Vol. 5, no. 1 (December 2012), p. 1-10 ISSN: 1756-3305
PDF PDF
Resumen en: Inglés |
Resumen en inglés

Background: Car tires are important habitats for mosquito development because of the high density populations they can harbor and their presence in urban settings. Water in experimental tires was treated with one of three insecticides or an untreated control. Aquatic invertebrates were sampled at weekly intervals. Eggs, larval and pupal samples were laboratory-reared to estimate seasonal fluctuations in Aedes aegypti and Ae. albopictus abundance. Results: Spinosad treatments at 1 or 5 ppm (mg a.i./liter) provided 6–8 weeks of effective control of Ae. aegypti, Ae. albopictus, Culex quinquefasiatus and Cx. coronator larvae, both in the dry season and the rainy season when mosquito populations increased markedly in southern Mexico. Spinosad continued to provide partial control of larvae for several weeks after initial recolonization of treated tires. The larvicidal performance of VectoBac 12AS (Bacillus thuringiensis var. israelensis) was relatively poor with one week of complete control of Aedes spp. larvae and no discernible control of Culex spp., whereas the duration of larvicidal activity of 1% temephos mineral-based granules was intermediate between those of VectoBac and spinosad treatments. Populations of chironomids, ostracods and Toxorhynchites theobaldi were generally reduced in spinosad and temephos treatments, but were similar in control and VectoBac treatments. Conclusion: The present study is the first to report spinosad as an effective larvicide against Cx. coronator, which is currently invading the southern United States. These results substantiate the use of spinosad as a highly effective mosquito larvicide, even in habitats such as unused car tires that can represent prolific sources of adult mosquitoes.


Resumen en: Inglés |
Resumen en inglés

Field trials were conducted during the wet and dry seasons in periurban and semi-rural cemeteries in southern Mexico to determine the efficacy of a suspension concentrate formulation of spinosad (Tracer 480SC) on the inhibition of development of Aedes albopictus L. and Ae. aegypti Skuse. For this, oviposition traps were treated with spinosad (1 or 5mg L−1), Bacillus thuringiensis israelensis (Bti, VectoBac 12AS), a sustained release formulation of temephos and a water control. RESULTS: Ae. albopictus was subordinate to Ae. aegypti during the dry season, but became dominant or codominant during the wet season at both sites. The two species could not be differentiated in field counts on oviposition traps. Mean numbers of larvae + pupae of Aedes spp. in Bti-treated containers were similar to the control at both sites during both seasons. The duration of complete absence of aquatic stages varied from 5 to 13 weeks for the spinosad treatments and from 6 to 9 weeks for the temephos treatment, depending on site, season and product concentration. Predatory Toxorhynchites theobaldi Dyar and Knab suffered lowmortality in control and Bti treatments, but highmortality in spinosad and temephos treatments. Egg counts and percentage of egg hatch of Aedes spp. increased significantly between the dry and wet seasons, but significant treatment differences were not detected. CONCLUSION: Temephos granules and a suspension concentrate formulation of spinosad were both highly effective larvicides against Ae. aegypti and Ae. albopictus. These compoundsmerit detailed evaluation for inclusion in integrated control programs targeted at Ae. aegypti and Ae. albopictus in regions where they represent important vectors of human diseases.