Assessment of Hyptis suaveolens Extract-Infused Candle Wax as a Mosquito Biorepellent

Abstract

Neurotoxic chemicals, including pyrethroids, neonicotinoids, and chlorinated hydrocarbons, have been effective for mosquito control; however, their continued use has resulted in widespread insecticide resistance. This resistance has necessitated increased insecticide application, a phenomenon known as the pesticide treadmill, which poses significant risks to both environmental and human health. Consequently, there is a growing need for sustainable alternatives with minimal adverse impacts. Although plant-based repellents have shown promise, many are formulated as topical products that may be costly, inconvenient, or culturally unacceptable in some communities. Despite the documented mosquito-repellent properties of Hyptis suaveolens, its traditional use relies largely on fresh plant material, which is limited by seasonality and may not provide year-round protection. In addition, evidence on practical, sustained-release delivery systems for plant-derived mosquito repellents remains limited. Candle wax represents a readily available and culturally familiar medium that may facilitate the gradual release of volatile repellent compounds during combustion without requiring direct skin application. This study therefore evaluated the mosquito-repellent efficacy of Hyptis suaveolens extracts infused into candle wax as a simple plant-based delivery system. Leaves of H. suaveolens were collected, air-dried, ground, and extracted using ethanol and water. The crude extracts were incorporated into melted candle wax at a 5:10 concentration, then solidified and burned in a mosquito-infested room for 30 minutes. Results indicated that rooms with infused candles had significantly fewer mosquitoes than the control room. These findings support the mosquito-repellent properties of Hyptis suaveolens and demonstrate that its incorporation into candle wax is a promising plant-based delivery system for mosquito control, warranting further evaluation under field conditions.