The effects of different land-use types on edible termite biodiversity in the Vhembe district municipality of Limpopo province
Netshifhefhe, Shandukani Rudolf
The changing land use patterns result in the risk of losing many of the valuable economic services (ecosystem services and human food) provided by termites. Termites are rich in proteins, fats, vitamins and many essential mineral nutrients and are valuable economic contributors to food security. This study investigated the entomophagy of termites in the Vhembe District Municipality of the Limpopo Province, South Africa and the effects of different land use types (communal grazing lands, maize fields and mango orchards) on the biodiversity of termites and the distribution of the edible termite mounds. Interviews using a structured questionnaire were conducted with 104 individuals comprising termite harvesters, consumers and sellers. The consumption of termites was recorded in 48 villages over three local municipalities, normally eaten with maize meal porridge. Three termite species are consumed by people in the Vhembe District Municipality and these are Macrotermes falciger, M. natalensis and M. michaelseni. Although M. natalensis is eaten throughout Africa, this study showed that soldiers of M. falciger is the preferred termite species consumed (89.90%) of all termites. Most of the respondents rated health benefits or nutrition and poverty as the main reasons for consumption. Macroternes falciger soldiers were the most eaten and the monetary contribution. Three termite sampling methods were evaluated using standard transects of 2 x 100 m. A combination of transect search method and cattle dung bait method gives good indication of termite diversity. Termites were collected from three land use types using a standardized transect sampling protocol and baiting methods. Communal grazing lands recorded higher functional and taxonomic diversity with 15 termite species from five subfamilies and 10 genera, and a higher Shannon (H’) and Simpson (1 - D) indexes of 2.23 and 0.84 respectively. Non-edible species of the genus Microtermes were the most dominant in the maize fields. Mounds were generally random distributed across all the land-use types. The mean number of termite mounds per hectare was higher in communal grazing lands (52.5) as compared to the maize fields (14.75) and mango orchards (7). Communal grazing lands were dominated by small and medium sized non-edible mounds of Trinervitermes sp while the maize fields had a greater density of M. natalensis mounds. Although the heights were roughly the same, the mound diameter and circumference of M. falciger was statistically larger than that of M. natalensis. Termite species diversity and abundance varies across land use types with human activities and agricultural intensification causing a significant decline in termite diversity which has considerable implications for the ecosystem function, and impact negatively on the availability of termites as free sources of protein.
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy in Insect Ecology School of Animal, Plant and Environmental Sciences December 2018