Where they can be found
: Mopane worms feed on the leaves of the mopane tree (Colophospermum mopane
). In Southern Africa, mopane tree areas stretch from northern parts of South Africa (Limpopo and Mpumalanga provinces) into Zimbabwe, Zambia, Botswana and northern Namibia. Although mopane worms feed mainly on the mopane tree, they are not limited to this diet, and can feed on many other trees that are indigenous to the same regions as the mopane tree, including the leaves of the mango tree. Thus the mopane worm is scattered over a fairly large area. In Zimbabwe, mopane worms are mainly found in the southern districts (Chivi, Mwenezi, Mberengwa, Beitbridge, Chiredzi and Gwanda).
What is harvested – Harvesting time: Mopane worm outbreaks are seasonal. There is usually one main harvest per year, during the early months of the rainy season (November to January) but a smaller second harvest occurs in April-May following good rains.
Population numbers vary from year to year based on the availability of rainfall and presence of host tree leaves.
A preferred time for harvesting the larvae is when they are in the 5th larval stage, just before pupation. If they are collected at this time, no squeezing is required as the larvae empty their guts naturally before going underground. However the collecting window where there are enough on the ground to make it worthwhile is relatively brief and hence people collect prior to this. There may also be a certain amount of “we had better get there first” involved.
Average yield per collector: Outbreaks of mopane worms, although seasonal, are timely in that they occur during the early months of the rainy season, traditionally referred to as the hunger season, when most rural households are in dire need of cash for food and school fees. Collectors can harvest between 25 and 50kgs of mopane worms per day. To avoid extinction, 10% of the worms should be left per tree for every harvest. Women and children take part in collection and sale of the worms. In recent years men have been involved, attracted by income-earning opportunities. Post harvest squeezing (removing of gut contents), parboiling and drying/roasting of mopane worms follow prior to selling at the market.
Farming: Wild outbreaks are unpredictable as they are influenced by a complex range of biotic (diseases and parasites), climatic and other factors that make harvesting and harvest income undependable.
Mopane worm farming is a semi-wild practice and includes all stages from egg to adult moth production in a protected and monitored environment. Eggs are collected and stored till they hatch or they can be protected with chiffon sleeves on the tree. Once the eggs hatch into larvae, they need protection from predators and parasites by use of bird deterrents and shade cloth. Caterpillars can be moved from one tree to another if there is overpopulation or if the leaves have been depleted. When they reach the 5th instar, they are ready for harvest. Approximately 10% of the larvae should be left to perpetuate the cycle. Caterpillars can be transferred to pits for pupation. Prior to moth hatching, the pupae can be transferred into cardboard boxes where male and female pupae hatch. The moths can then be released at the base of a host tree under a shade cloth net. The moths lay eggs on the tree and the cycle can be repeated all over again.