Preliminary Assessment of Insect-Repellent Activity of Curcuma amada and Curcuma aromatica Rhizome Peel Extracts through Field Application

The increasing demand for eco-friendly and sustainable insect control agents has led to the exploration of plantderived bioactive compounds that possess repellent properties. In this study, the insect-repellent potential of peel Curcuma amada (mango ginger) and Curcuma aromatica (wild turmeric) rhizomes peels using simple direct-area applications under open or semi-open conditions was carried out. Ethanol extracts were applied to exposed surfaces and plant leaves, and repellency was assessed against mosquitoes (Culex spp.), Drosophila melanogaster, and aphids (Aphis craccivora). Both extracts exhibited prompt repellency responses, ranging from initial application upto 10 min, depending on the insect species tested. However, C. aromatica peel extract consistently showed a longer duration of repellent effect across all three insect types, lasting up to 30 h in the case of aphids. C. amada also exhibited significant activity but with shorter persistence. These results highlight the potential of exploring rhizome peels, typically considered agricultural waste, as effective, low-cost botanical repellents. This study emphasizes a practical, real-environment approach to testing without the use of containers or enclosures, thus mimicking field conditions. These findings support further phytochemical and formulation research for the development of natural insectrepellent products using Curcuma peels.