Ethnobotanical survey of plants used as repellents against housefly, Musca domestica L. (Diptera: Muscidae) in Budondo Subcounty, Jinja District, Uganda.

BACKGROUND: The housefly, Musca domestica L., is a major public health and domestic pest that spoils food and causes irritation and is a vector of many infectious disease pathogens of medical and veterinary importance. Currently, its control relies largely on chemical pesticides. However, the adverse health and environmental effects of pesticides, risk of development of insect resistance, and bioaccumulation through the food chain emphasize the need to search for environmentally friendly alternatives. This study aimed at documenting traditional knowledge about plants used as repellents against the houseflies by the people of Budondo Subcounty, Uganda.

METHODS: An ethnobotanical survey was conducted between November 2016 and June 2017. A total of 372 household members were interviewed on knowledge and use of traditional insect repellents, through face-to-face interviews guided by semi-structured questionnaires administered in nine villages in Budondo Subcounty.

RESULTS: Overall, only 24.5% of the respondents had ample knowledge about insect repellent plants. A chi-square analysis shows a significant association between respondents' knowledge of insect repellent plants and age, educational status, occupation, religion, and marital status although not with gender. Overall, eight plants from seven families and eight genera were mentioned as repellents. The growth forms encountered were tree, shrub, and herb. Plants that were commonly mentioned by respondents were Cupressus sempervirens L. (16.9%), followed by Lantana camara L.(16.1%), Eucalyptus globulus Labill. (11.0%), Carica papaya L. (8.6%), Cymbopogon citratus (de Candolle) Stapf (4.3%), Mentha × piperita L. (2.4%), Azadirachta indica A. Juss (2.2%), and Ocimum kilimandscharicum Gürke (0.8%) in descending order. Leaves were the most commonly used plant part (76.9%), followed by the stem/bark (19.8%), flowers (2.2%), and root (1.1%). Burning of the plant materials in order to generate smoke was the most popular method of application.

CONCLUSIONS: This study has shown that there are many locally available plants in use by the people of Budondo Subcounty with potency for repelling houseflies. Further studies are needed to identify bioactive compounds responsible for the repellent activity in the different species which could be promoted as sustainable housefly control tools in these remotely located communities of Budondo. Furthermore, studies on the efficacy of these repellent plants or plant parts and their potential toxicological properties should be considered a priority.