In a spin for silk
Although not usually considered a minilivestock activity, wild African silkmoths have been exploited in the past but could now be partially domesticated to generate valuable income for farmers. Asian countries are no longer producing enough raw silk to satisfy demand but African farmers could reap the benefits of this market opportunity by supplementing their income with silk production, or sericulture. ICIPE, based in Nairobi, is providing farmers in Kenya and Uganda, with the opportunity to produce valuable tussar silk from indigenous African silkmoths.
Until recently, very few people were aware of the potential of wild African silkmoths. In some regions, silkworms (e.g. Bunea alcinoe) were killed in large quantities and eaten as a source of protein (see edible insects). Only in Botswana were they exploited for their silk but there they were collected in such large numbers that several species became extinct. However, from the variety of wild silkmoths to be found across Africa, two indigenous Gonometa species, found only on Acacia trees, have been selected for breeding and production by ICIPE. Unlike Asian silkmoths, which have been domesticated over hundreds of years, the wild African silkmoths are not easy to rear in captivity. So ICIPE has set up a system of partial-domestication: the moths have to be caught in the wild in order to lay their eggs in the laboratory but once they are hatched, the larvae are released back into the wild to feed on Acacia leaves until they spin their cocoons. However, domestic rearing of wild silk may soon be possible, as the edible saturniid moth (B.alcinoe) has been successfully reared in the laboratory on leaves of its host plant, Balanites aegyptica. Attempts are now being made to develop an artificial diet for laboratory rearing.
Silk production requires effort and persistence, particularly from the wild silkmoths. However, local farmers are offered training by ICIPE for collecting cocoons in a sustainable manner to preserve wild populations and to obtain enough silk to provide them with a generous income. Dr Suresh Raina, Project Co-ordinator for Commercial Insects at ICIPE, is responsible for promoting sericulture in Africa and he is particularly keen to include regions where although wild silkmoths have not been exploited directly by humans, their populations are still threatened as their habitats are being eroded. Wild silk production can therefore provide a strong economic incentive for rural communities to adopt sound land management practices in addition to subsistence agriculture.
In parallel, the success of domesticated sericulture, which is also beginning to flourish in Africa, is demonstrated by the number of groups now involved in silk production in Kenya: over 100 farmer groups of varying sizes (from a few to over 200) have become interested in this valued micro-enterprise. In Tanzania, about 300 farmers near Arusha are involved in silk and honey production and in Uganda, reeling and de-reeling machines have been provided by ICIPE to help post harvest processing of silk cocoons. For domestic silk production in Africa, ICIPE has developed a hybrid by crossing a number of domestic silkmoth (Bombyx mori) strains, which is suited to climatic conditions in Africa and produces a high quality silk.* ICIPE - International Centre of Insect Physiology and Ecology (Email: ICIPE@ICIPE.org)