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The sterile insect technique (SIT) is a promising pest control method in terms of efficacy and environmental compatibility. In this study, we determined the efficacy of thiotepa-sterilised males in reducing the target Aedes aegypti populations. Treated male pupae were released weekly into large laboratory cages at a constant ratio of either 5:1 or 2:1 sterile-to-fertile males. A two-to-one release ratio reduced the hatch rate of eggs laid in the cage by approximately a third and reduced the adult catch rate by approximately a quarter, but a 5:1 release drove the population to elimination after 15 weeks of release. These results indicate that thiotepa exposure is an effective means of sterilising Ae. aegypti and males thus treated are able to reduce the reproductive capacity of a stable population under laboratory conditions. Further testing of the method in semi-field enclosures is required to evaluate the mating competitiveness of sterile males when exposed to natural environmental conditions. If proven effective, SIT using thiotepa-sterilised males may be incorporated into an integrated programme of vector control to combat dengue in Cuba.

En este trabajo nos trazamos como objetivo evaluar la actividad repelente de diferentes formulaciones del aceite de Melaleuca quinquinervia Cav S.T. Blake en condiciones de laboratorio y terreno. Se prepararon formulaciones etanólicas, hidroalcohólicas, hidrofíli-cas y en base oleosa con aceite mineral y dipropilenglicol. Se trató el antebrazo con 1 ml de repelente y la mano fue cubierta con un guante de goma. El antebrazo fue expuesto por 3 minutos cada media hora. Se obtuvo una tendencia positiva del tiempo de protección con el aumento de la concentración. El mayor tiempo de protección observado (5 horas) fue con la cepa Santa Clara y la formulación de aceite al 20 % en dipropilenglicol Con estos resultados se evaluó en condiciones de terreno obteniéndose tiempos de protección promedio de hora y media. El repelente formulado con dipropilenglicol y aceite de Melaleuca quinquinervia al 20% es adecuado para las labores del personal dedicado a la protección de bosques y costas.Palabras clave: Aceite esencial, repelente, Aedes aegypti. Abstract Repellent activity of essential oils formulations from Melaleuca quinquenervia (Cav.) S.T. Blake (Myrtales: Myrtaceae) on mosquitoesThe study was carried out in order to evaluate the repellent activity of different formulations of Melaleuca quinquinervia Cav ST Blake oil, in laboratory and field conditions. Ethanolic, hydroalcoholic, and hydrophilic formulations were prepared in mineral oil and dipropylene glycol. In laboratory experiments the forearm was treated with 1ml of the repellent, and exposed against different Aedes aegypti strains by 3 minutes every half hour. The hand was protected or covered with a rubber glove. A positive protection trend was observed when the concentrations of the different formulations were increasing. The higher protection was observed (5 hours) in Aedes aegypti Santa Clara strain with 20% dipropyleneglycol oil formulations. These laboratory results were evaluated then in field conditions, obtaining average protection times of 1 ½ hours.

Background: The efficacy of biolarvicides may be influenced by species of mosquito, larval age and density, tem­perature, water quality, bacterial formulation, and others. The aim of this study was to evaluate the influence of tem­perature and chlorine on larvicidal activity of Bacillus thuringiensis Cuban isolates against Aedes aegypti. Methods: The influence of temperature (25, 30, 35 °C) and chlorine (2.25mg/L) on the larvicidal activity of eleven B. thuringiensis Cuban isolates (collected between 2007 and 2009) were tested under laboratory conditions following WHO protocols. Bioassay data were analyzed by Probit program. The effect of chlorine and temperature (25, 30, 35 and 40 °C) on the Cry and Cyt proteins of these isolates was determined by SDS-PAGE polyacrylamide gel electro­phoresis. Results: The pathogenicity of the isolates U81, X48 was affected at 35 °C. However, A21, A51, L910, and R89 isolates increase their entomopathogen activity at 35 °C. No differences were observed in toxicity of M29, R84, R85 and R87 isolates at different temperatures. The Cry 4, Cry 10 and Cry 11 proteins were reduced in A21, X48, R85 isolates at 35 and 40 °C. The Cyt proteins were reduced at 35 and 40 °C in A21, X48, R85, and A51 isolates. In L910 and R84 isolates, the Cyt toxin was degraded only at 40 °C. In chlorinated water, the lethal concentrations 50 and 90 in A21, A51, M29, R84, U81, and X48 isolates were increase. Conclusion: A21, A51, L910, R85, and X48 isolates have a strong larvicidal activity for the treatment of Ae. aegypti breeding’s sites exposed to high temperature and chlorine