Impact of Lime Water on Different Developmental Stages of Aedes aegypti

Objective To investigate the intervention effect of quicklime on the prevention and control of Aedes aegypti through an experimental study on the impact of lime water on different developmental stages of Aedes aegypti, and to provide experimental data for quicklime used in the prevention and control of Aedes aegypti.

Methods A certain number of Aedes aegypti mosquitoes in different developmental stages (egg, larvae at I-IV instar, and pupae) were collected and fed in lime water, respectively, to observe the activity of mosquito larvae, and the corresponding hatching time, hatching rate, and mortality rate were recorded in different periods of time; at the same time, Aedes aegypti mosquitoes fed with dechlorinated tap water in laboratory were established as control group, and a comparative analysis was performed for the development of Aedes aegypti mosquitoes in different feeding environments and developmental stages.

Results The mean hatching time of Aedes aegypti eggs in the experimental group (fed with 1.3 g/L lime water) was 2.19 times than that in the control group (3.84 days vs 1.75 days, t=36.02, P < 0.05), and there was a significant difference in the hatching rate of Aedes aegypti eggs between the experimental group and the control group (59.3% vs 89.3%, χ²=35.38, P < 0.05). In the experimental group, the mortality rates of I-IV instars were 44.0%, 92.0%, 97.3%, and 98.7%, respectively, which were significantly higher than those in the control group (χ² were 65.79-276.53, P < 0.05). In the experimental group, the mortality rate of pupae was 98.7%, which was significantly higher than that in the control group (χ²=280.35, P < 0.05). In the control group, the mortality rates of Aedes aegypti eggs, larvae, and pupae were 10.7%, 2.3%, and 2.0%, respectively, with a significant difference between the three groups (χ²=25.09, P < 0.05), and the mortality rate of Aedes aegypti eggs was significantly higher than that of mosquito larvae and pupae. In the experimental group, the mortality rates of Aedes aegypti eggs, larvae, and pupae were 40.7%, 83.0%, and 98.7%, respectively, with a significant difference between the three groups (χ²=170.88, P < 0.05).

Conclusion Lime water has a marked inhibitory effect on different developmental stages of Aedes aegypti, with the greatest killing effect on pupae, followed by mosquito larvae and eggs. The inhibitory effect of lime water on Aedes aegypti is gradually enhanced with the increasing age of Aedes aegypti larvae; however, further field studies are needed to verify the effect of quicklime in the prevention and control of Aedes aegypti mosquitoes.