Traditional knowledge of people on plants used as insect repellents and insecticides in Raya-Azebo district, Tigray region of Ethiopia
The study aimed to document and assess local knowledge on the use of insecticidal and insect repellent plants to manage disease-transmitting, nuisance and crop pests in Raya-Azebo district of Tigray region of Ethiopia. Ethnobotanical data were collected through semi-structured interviews conducted with purposively selected informants. Simple preference ranking exercises were conducted by ten informants to identify the most important insect repellent plants in the district. Samples of reported plants were collected, identified and deposited at the National Herbarium, Addis Ababa University. The study revealed the use of 35 plants, of which 22 (63 %) were used as insect repellents (mainly against mosquitoes), 12 (34 %) both as insect repellents and insecticides and 1 (3 %) as insecticide. Olea europaea subsp. cuspidata, Klenia odora, Silene macrosolen and Aloe trichosantha were the most preferred insect repellent plants as revealed by preference ranking exercises. The results showed a significant difference (p < 0.005) in the mean numbers of reported insecticidal and insect repellent plants between older and younger people where older people reported more number of plants. In the future, pharmacological and phytochemical evaluations should be conducted on the most preferred insect repellent plants in the District as revealed by informant consensus and preference ranking exercises.