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4 resultados encontrados para: TEMA: Temefos
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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
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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.


2.
- Artículo con arbitraje
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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.


3.
- Artículo con arbitraje
Efectividad residual de temefos en una ciudad del sureste mexicano prevalente al dengue
Antonio Arreola, Gloria Elsa ; Sánchez Guillén, Daniel (coaut.) ;
Contenido en: Revista Cubana de Medicina Tropical Vol. 64, no. 2 (mayo-ago. 2012), p. 176-186 ISSN: 0375-0760
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Resumen en: Español | Inglés |
Resumen en español

Objetivo: investigar en qué medida la actividad residual del temefos aplicado a 1 ppm en tanques de cemento domiciliares es afectada por la extracción y reposición de agua derivada de las actividades diarias en el hogar. Métodos: el estudio se realizó en 2 etapas: primero la determinación de la efectividad del temefos granular en poblaciones silvestres de Aedes aegypti para establecer una línea basal de monitoreo y, segundo, la medición de la tasa media de extracción de agua domiciliar y su efecto sobre la residualidad de temefos. Resultados: la efectividad del temefos granular fue de CL95= 0,095 ppm (IC95 %: 0,079 0,118). Se encontró que, en promedio, se usa y repone diariamente el 69,2 % del agua almacenada en tanques de cemento, lo cual indica dilución significativa. Para simplificar los experimentos de residualidad se extrajo y repuso el agua a una tasa de 50 % diaria durante 2 semanas, encontrándose que la efectividad del temefos disminuye significativamente a partir del día 7 de su aplicación. Conclusiones: la extracción de agua a la tasa encontrada tiene efectos importantes en la residualidad de temefos. Si se considerara esta tasa de extracción de agua y la CL95 del temefos granular en el cálculo de su dosificación, se tendrían efectos positivos en el control de Aedes aegypti y muy posiblemente en la aparición de resistencia.

Resumen en inglés

Objective: to study the effect of water extraction and renewal on the residual action of temephos applied at 1ppm to cement water-storage containers at home. Methods: the study was conducted in two stages: one, determination of the granular temephos effectiveness on wild Aedes aegypti populations in order to set the monitoring baseline; and second, the measurement of the mean rate of water extraction at home and its effect on the residual activity of temephos. Results: the effectiveness of granular temephos was CL95= 0.095 ppm (IC95 %: 0.079-0.118). As average, it was found that 69.2 % of water stored in cement containers was daily used and renewed, which means significant dilution. For the purpose of simplifying the experiments on residual activity, water was extracted and renewed at a rate of 50 % every day for 2 weeks. It was found that temephos effectiveness significantly declined from day 7 on after application. Conclusions: this rate of water extraction under study has an important effect on the residual activity of temephos. If this rate and the CL95 of granular temephos are considered in estimating the dosing, positive effects on the control of Aedes aegypti and more likely on the occurrence of resistance will be attained.


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.