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

Abstract

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.

Keywords: Ethnobotanical survey; Insecticide; Repellent; Traditional knowledge.

Fig. 1

Location of Xishuangbanna and sites of ethnobotanical surveys of plant-based remedies to control hematophagous invertebrates (including villages of Bulang, Jinuo, and Lahu and previous research sites of Dai and Hani villages).

Fig. 2

The process of ritual incense of Lahu people in Xishuangbanna. The bark of Cinnamomum bejolghota (A) and Cinnamomum iners (B) were dried (C) and ground down (D) into powder. Then, the powder was mixed with hot water (E) and applied on the stick (F). Finally, after drying, the incense can be burned to generate smoke (G).

Fig. 3

Ethnic group-plant species network. Plant species are shown linked to the five ethnic groups (green). Plant vertices with purple, fuchsia, blue, brown and red indicate plants reported by 5, 4, 3, 2, and 1 ethnic group(s), respectively. The values along the edges (lines/connections) indicate the number of URs directed to plant species as contributed per ethnic group. The size of the node is converted from the number of URs of the plant.

Fig. 4

Heat map for targeted categories, as recorded per ethnic group in Xishuangbanna (B-Bulang, J-Jinuo, L-Lahu, H-Hani, and D-Dai). The blue map shows the number of applicable plant taxa (Nt) recorded per ethnic group, while the green map represents the degree of UR (Nur). Informant consensus factors (ICFs) were calculated for each target category of the five ethnic groups.

Fig. 5

Three plants with the most potential to be developed as insecticides or repellents. A, Artemisia indica; B, Nicotiana tabacum; and C, Clausena excavata.