Toxicity of sodium tellurite (Na2TeO3) against Aedes caspius larvae in Gizan, Southwestern region, Kingdom of Saudi Arabia

Abstract

The most common mosquito-borne diseases in Saudi Arabia are dengue, filaria, malaria and Rift valley fever. Rift valley fever /Dengue outbreaks in Mediterranean region have progressively increased, with recent reports of cases in Saudi Arabia. A serious out break had been seen in the southern coastal province of Jazan of Saudi Arabia. Tellurium is considered to be an important element in emerging world of corrosion resistance technology and glass ware technology. There was no literature available on mosquito larval toxicity. Thus this compound has stimulated our interest to evaluating the toxicity effect against mosquito larvae. The toxicity of Sodium tellurite was performed against Aedes caspius as per WHO methods. Preliminary toxicity of Sodium tellurite was evaluated at 200 ppm concentration in different time interval like 6 hrs, 12 hrs, 18 hrs and 24 hrs and percent mortality was recorded as 21.66%, 55%, 94% and 100% respectively against larvae.Therefore, further quantitative assay were carried out in different concentration of tellurite which was less than preliminary concentration such as 25 ppm, 50 ppm, 75 ppm, 100 ppm, 125 ppm, 150 ppm and 200 ppm. The LC50 and LC90 value was observed 37.5 ppm and 105 ppm respectively against the Ae. Caspius larvae. No mortality was observed in control group in all experiments. In conclusion, the Sodium tellurite are effective and may be developed as potent larvicides in future.