Citrus-Based Bio-Insect Repellents—A Review on Historical and Emerging Trends in Utilizing Phytochemicals of Citrus Plants

Abstract

Research on citrus plants is the result of increasing interest in the discovery of plant species with potential insect-repellent properties. Insect-repelling ability can be achieved by the numerous ubiquitous citrus species. This is mainly due to the presence of phytochemicals such as limonene, citronellol, citral, and α-pinene. These phytochemicals’ composition varies depending on the geographical location of the plant. The extraction method dictates the configuration of attainable phytochemicals while the dosage affects the repellency potential. Therefore, developing insect repellent involved a number of observations related to the identification of both citrus plant phytochemical composition present in the different parts of the plant and the repellency potential of these phytochemicals in advance. Conversely, the development of repellent methods that go beyond conventional methods has been made possible by scientific developments including modern strategies such as encapsulation, the preparation of emulsion, and the incorporation of repellents into textiles. Therefore, this review article intends to probe into the aforementioned information and provide a sound insight into citrus-based repellent development in the future.