Ethnobotanical survey of plants traditionally used against hematophagous invertebrates by ethnic groups in the mountainous area of Xishuangbanna, Southwest China

Hematophagous invertebrates such as mosquitoes, leeches, mites, ticks, lice and bugs cause various problems for humans. Considering reports on insecticide resistance and requirements for improved environmental and toxicological profiles, there is a continuing need to discover and develop new insecticides and repellents. Ethnobotanical surveys of traditional plant-based repellents provide a direct method of identifying plants for potential use. During five field surveys in Bulang, Jinuo and Lahu villages between August 2018 and July 2019, semi-structured interviews were conducted with 237 informants (151 male, 86 female; mean age 63). Frequency of citation, use value, informant consensus factor and Jaccard index were employed to statistically analyze the collected data. A total of 709 use reports relating to 32 plant species and 71 remedies were collected. Similarities and differences between the three groups, as well as the Dai and Hani of Xishuangbanna, who were studied earlier, were shown through network analysis. These five ethnic groups living in the same area have a common understanding of traditional botanical knowledge against hematophagous invertebrates, but each group also possesses unique knowledge. Recording and protecting this traditional knowledge is potentially useful for protecting this cultural diversity and related biodiversity and can also have important practical applications. In this study, traditional knowledge provided us with many new potential plants for follow-up research for the development of new insecticides and repellents, among which Artemisia indica, Nicotiana tabacum and Clausena excavata are the most promising.