Culturally and economically significant insects in the Blouberg Region, Limpopo Province, South Africa

Thesis (PhD. (Zoology)) --University of Limpopo, 2013

Edible insects have been used as a nutritious food source by mankind for millennia, but in the modern era their use in more industrialised and western countries has dwindled. In the face of concern over the global food security crisis, scientists are urging investigation into edible insects as an alternate food. This study contributes to this global initiative by investigating entomophagy in the Blouberg area of the Limpopo Province, South Africa. The research develops a database of Blouberg edible insects, documents the importance of entomophagy to the people of Blouberg and for the wider community, and investigates aspects of the biology, ecology, socio-economics and nutritional value of a key species harvested in the area. Semi-structured questionnaires were carried out between 2007 and 2008 amongst households in the vicinity of Blouberg Mountain. Nearly 91% of the households in the Blouberg area consume insects. The most important reasons cited for consuming insects are that they are a traditional food, that they taste good and that they are a free food resource. Twenty eight species of edible insects were identified to at least genus level. Education was more important than income in influencing whether or not insects were consumed in a household. Households with lower education scores were more likely to consume insects than those with mid-level education scores. However, those with low income scores consumed a greater quantity of insects than those with higher scores. Similarly, those with low education scores consumed more insects than those with higher education scores. Pasture land was the area most preferred for collecting insects, with crop lands second in importance. Natural vegetation was not a preferred collecting habitat. Most households (78.57%) believe there has been a decline in edible insect consumption in recent years. According to the Blouberg insect collectors, edible insects are also on the decline in Blouberg and most households are unhappy about this. The lepidopteran, Hemijana variegata (bophetha), which was targeted for more in depth research, was found to be univoltine in the field, with caterpillars emerging in early November. The caterpillars feed predominantly on Canthium armatum and to a lesser extent on Pyrostria hystrix. They take four weeks to develop, burrowing into the soil to overwinter as pupae to emerge as adults in late spring. The development of the moth is profoundly influenced by temperature at all life stages and ceased below 17ºC and above 35ºC. Temperatures between 23ºC and 29ºC were most favourable for growth. The food value of the bophetha caterpillars was found to be high. The protein value of traditionally prepared caterpillars is 45.5%, with carbohydrates at 11.86 mg/100 g and fat at 19.75%. The caterpillars are not as rich in vitamins as fruit or vegetables, but compare favourably with beef. Traditionally prepared bophetha were found to be contaminated by two bacteria and one fungus, none of which are dangerously pathogenic to humans. Bophetha are traded between Blouberg villages at costs equivalent to other edible insects in South Africa (R10.19 per cup). Almost one third of Blouberg inhabitants sell bophetha, with this percentage decreasing to about 10% in poor seasons. Households collect between 3 and 3.5 litres of bophetha per season. Blouberg households are of the opinion that knowledge about edible insects is important enough that it should be included in formal education as a way of ensuring that the younger generation assimilates aspects of this knowledge despite cultural changes. The results of the study emphasise the importance of natural resource use with respect to edible insects in a marginalised community.