Ethnobotanical knowledge and practices of pastoralist communities on plants used as repellents and/or insecticides against insect vectors in the Korahaye zone of the Somali Regional State, eastern Ethiopia

Abstract

Background Combined efforts to combat both outdoor and indoor transmission of malaria parasites are hampered by emerging vector resistance in a wide range of endemic malaria settings in Ethiopia and the rest of the world, stressing the need for developing and implementing alternative control measures. This study aimed to document indigenous pastoralist knowledge on the use of repellent and insecticidal plant species against insect vectors in a number of kebeles in the Somali Regional State, eastern Ethiopia. Methods Data were collected by interviewing a total of 120 informants (105 men and 15 women) through face-to-face interviews guided by a semistructured questionnaire, observing information on the preparation method, and performing a guided field walk with a guide to collect plant specimens. The ethnobotanical survey was carried out 5 May 2018-12 April 2019. Medicinal plant specimens were collected following a standard approach, and voucher specimens were deposited in the Jigjiga University mini herbarium. The data were analyzed using descriptive statistics, preference rankings, paired comparisons and direct matrix rankings. Results A total of 52 voucher specimens belonging to 47 genera and 34 families were obtained. Of these, 42 were reported to be repellents against mosquitoes or insects in general. Among the plant families recorded, Fabaceae had the highest number of plant species, 5 (9.61%). The best-represented life forms were herbs (21, 41.96%), followed by shrubs (17, 32.69%). Leaves were the most commonly used plant part for remedy preparation and accounted for 18 (33.96%) of the total plants. Among the repellent plant species documented, 57.68% were reported to be burned to produce in-house smoke, 20.37% were mashed, and the paste was applied on the body to repel insects. The plants that were commonly mentioned by respondents were Amaranthus sparganiocephalus (27 mentions, 22.5%), Phytolacca dodecandra (18, 15%), and Commiphora rostrata (26, 21.66%) for repellent, insecticidal, and both repellent and insecticidal uses, respectively. Conclusion The present study showed that pastoralist communities have valuable indigenous knowledge and practices related to the use of plants as repellents. This knowledge should be validated and confirmed experimentally and possibly promoted as a sustainable and ecosystem-friendly insect vector control tool.