An Emperor for Lunch


SOME people prefer not to eat worms. But many others enjoy munching on such boneless delicacies. A favorite food in parts of Africa is the caterpillar of the emperor moth, Imbrasia belina. There this creature is widely known as the mopane worm, named after the tree that serves as its favored host, the mopane tree. Many rural communities eagerly anticipate harvesting this wriggling, nutritious tidbit. “They are an incredibly important source of protein,” says Keith Leggett, of the Kalahari Conservation Society. The worms also play a valuable role in the ecology of the often dry and relatively infertile savanna woodlands.

 As summer rains spread across southern Africa during early November, the land comes alive. Millions of self-sufficient subterranean pupas are now elegant moths. In a matter of weeks, their offspring will grow from tiny eggs to larvas and then to colorful plump “sausages.”

In areas where starchy staples such as cassava and maize predominate, the caterpillars are a welcome supplement to the diet. Though not first on the menu for many of us, their more than 60 percent protein content makes them a valuable commodity, especially where quality protein is expensive or in short supply. A portion of edible caterpillars competes effectively with a portion of meat or fish, supplying approximately three quarters of an adult’s daily requirement of protein, vitamins, and minerals. Yes, these little creatures are nutritious!

Caterpillar consumers are surely puzzled at the expensive chemical warfare waged against such nutrient-rich insects by commercial farmers elsewhere. As millions of these creatures munch away, they convert often unpalatable, and sometimes toxic, leaves into a valuable food. All that without the use of expensive agricultural equipment and veterinarian fees! Harvested by hand, caterpillars are a highly efficient crop available for a minimum of effort.

Mopane worms make no small contribution to the fertility and ecological balance of bush land. While the size and considerable appetite of the African elephant are impressive, its digestive performance is dwarfed by the humble mopane worm. In their short, six-week existence, hordes of caterpillars devour about ten times as much vegetation and produce almost four times as much manure as elephants occupying the same grazing area. No wonder the caterpillar’s body mass increases by a staggering 4,000 times! Not surprisingly, therefore, uncontrolled harvesting has an impact on soil fertility and the ecological balance of the land.

How are these caterpillars harvested? Every rainy season women in rural areas gather for the first of two annual harvests of mopane worms. For several weeks they collect the worms, which are then gutted, boiled, and laid out to dry. However, harvesting and preparing certain other edible caterpillars demands special care. Protective hairs or spines gracing the bodies of some varieties have to be removed. Caution is also required in preparation because some caterpillars feed on plants that are toxic to humans. After processing, dried caterpillars can be eaten as a crunchy snack, though they are more often rehydrated and boiled in a stew or fried with tomato and onion.

The thought of eating caterpillars may make you feel anything from adventurous to uncomfortable. You may choose to wriggle out of the opportunity to try these exotic morsels. But remember, they represent an important high-protein food source and provide a supplementary income for many families in Africa.

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The mopane worm’s high protein content makes it a valuable commodity

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In its short six-week existence, the mopane worm’s body mass increases by 4,000 times