An Experimental Assessment of acute toxicity of Sodium Chloride against Aedes aegypti L. larvae

The prevalence of dengue, one of the most important mosquito-borne diseases, has increased more
than eight-fold during the past two decades. The primary and most prevalent mosquito vector,
Aedes aegypti L., is responsible for spreading viruses that cause dengue and other harmful diseases.
Control of vectors is of particular concern to block dengue transmission. Different chemical
measures used for vector control caused various environmental issues, mosquito resistance,
resurgence, and harmful impacts on non-target organisms increased attention towards cost-effective
and environment-friendly control measures. Hence, the present study aimed to check the larvicidal
potential of Sodium Chloride (NaCl) and examined its acute toxicity against 4 th instar larvae of Ae.
aegypti.Acute toxicity tests were conducted as per WHO guidelines. Different NaCl concentrations
i.e., 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% were prepared using pure NaCl along with distilled
water. The Larvicidal activity was assessed and toxicity values were computed using the Log-Probit
Method. Several morphological and behavioral alterations in treated Ae. aegypti larvae were also
observed. Sixty percent larvae of Ae. aegypti died after exposure to 1.5% NaCl concentrations
within 48 hours and larval mortality significantly increased up to ninety-seven and hundred percent
after treatment with more than 2% NaCl solution within 24 and 48 hours respectively. Various
ruptures were observed in the abdomen and anal papillae along with abnormal behavior in the
treated larvae. Our study concluded that Sodium Chloride can be used as an effective and safe
intervention in mosquito control programs due to its easy availability and less toxicity.