Effect of Hydrogen Peroxide on Oviposition Site Preference and Egg Hatching of the Aedes aegypti (Linnaeus) Mosquito.

Abstract

Hydrogen peroxide (H₂O₂) occurs in the environment, including in aquatic environments where mosquitoes might lay eggs. However, little is known about the compound's impact on mosquitoes. We conducted an experiment to determine the effect of H₂O₂ on Ae. aegypti oviposition behavior and egg hatching using H₂O₂ concentrations similar to those in natural aquatic environments. Oviposition behavior was evaluated by dual-choice and multi-choice bioassays. Gravid Ae. aegypti mosquitoes were placed in cages with containers with different H₂O₂ concentrations (5, 25, 50, and 100 μM). After 72 h, the number of eggs laid was compared between oviposition sites with and without H₂O₂. Additionally, egg hatching was assessed under long-period exposure (48 h) and short-period exposure (2, 4, and 6 h and then in deionized water for up to 48 h). Results showed no significant difference in oviposition preference scores in the multi-choice assay (OAI = -0.135 ± 0.06) (p = 0.138), but a significant difference in the dual-choice assay (0.195 ± 0.01) (p = 0.001). Long-period exposure to H₂O₂ did not significantly affect hatch rates (11.34%) (p = 0.363), but short-period exposure significantly impacted hatch rates (17%) (p = 0.0001), with period of exposure alone playing a significant role (p < 0.0044). Eggs exposed to 100 μM H₂O₂ for 2 h (p = 0.0070) and 4 h (p = 0.0036) had significantly higher hatch rates compared to the control. This study demonstrates that low concentrations of H₂O₂ can influence oviposition site characteristics and egg hatch rates. Combined with other environmental factors, H₂O₂ can shape the reproductive success of Ae. aegypti, offering potential strategies for mosquito control.