9th Experimental Archaeology Conference poster – Rifkin
EthnOGRAPHIC and experimental perspectives on the efficacy of RED ochre as an INSECT repellent
Riaan F. Rifkin
University of Bergen, Norway; University of the Witwatersrand, South Africa
The habitual exploitation of red ochre during the African Middle Stone Age (MSA) has been interpreted as a proxy for the origin of language, as evidence for colour symbolism and as a key element of modern and symbolic human behaviour. From at least 100 000 years ago, red ochre features prominently in human artistic expression and technological ingenuity.
Evolutionary hypotheses generally agree that ochre played a role in the adaptive strategies of Homo sapiens, but they differ widely in the functions they assign to it. That red ochre may have been used as an insect repellent is an enduring but unsubstantiated hypothesis for its exploitation. Ethnographic interviews conducted amongst the Ovahimba of the Kunene Region, Namibia, indicate that, besides the intrinsic symbolic significance of red ochre, it fulfils several functional roles, including that as an insect repellent. This paper presents the results of controlled in vivo and in vitro laboratory experiments designed to evaluate the efficacy of ochre as a mosquito repellent. It is demonstrated that certain types of ochre, mixed with clarified butter, provides a sufficient degree of protection from mosquitoes. It is concluded that, although the increase in the habitual exploitation of red ochre during the southern African MSA in all probability reflects a technologically mediated response to progressively more complex social circumstances, it may also represent an adaptive response to changing environments and increasing susceptibility to mosquito-borne diseases.