or cooked with onion, tomatoes and spices and then served with pap or sadza. The flesh is yellow, and the gut may still contain fragments of dried leaf, which is not harmful to humans. The taste of dried leaves, if not removed, is somewhat reminiscent of tea leaves. Dried mopane worms are frequently canned/packaged in tomato sauce or chili sauce to enhance the flavour. In November 2015, a Cornell team of food scientists placed third in Brisbane, Australia, at the 2015 Global Business Challenge, by presenting the economic and nutritional benefits of transforming proteins from mopane worms into food. Farming and economics The harvesting and sale of mopane worms is a multi-million rand industry in southern Africa. The principal producers are Botswana, Namibia, South Africa (Limpopo Province and Mpumalanga) and Zimbabwe. Typically, the caterpillars are not bred, but picked wherever they occur naturally. It is one of the region's most economically important insects. In the 1990s, hundreds of tons were exported from Botswana and South Africa each year. It is estimated that South Africa alone trades 1.6 million kilogrammes of mopane worm annually, and that Botswana's involvement in this industry nets it roughly $8 million annually. Mopane worms are considered to be a profitable harvest, as a mere three kilograms of feed (mopane leaves) will generally yield one kilogram of mopane worms: in contrast, cattle farming requires ten kilograms of feed to generate one kilogram of beef; thus the worms are a low-cost, low-maintenance, high-protein food source. Harvesting Traditionally, mopane worms were harvested for subsistence. Because of the seasonal nature of the occurrence of these edible caterpillars, they are not a year-round food source. However, traditional mopane worm harvesting is evolving to be more commercially driven. Since the 1950s, commercial farming methods have been applied to the mopane worm harvests, particularly in South Africa. Collectors may organise teams of hundreds of people to hand pick the caterpillars from the trees, after which they are bagged en masse, weighed, and sent off to be processed. Owners of land where mopane worms are found may charge harvesters large fees to enter. Whereas this relationship profits both the commercial harvester and the farmer, it is often to the detriment of the local community for whom the caterpillars may previously have been an important source of food and seasonal income. Sustainability As mopane worms represent an important sector in the local rural economy, they