Edible Caterpillars and their Food Plants in Bas Congo, Democratic Republic of Congo
Volume 3 Number 3 - December 1999
Caterpillars are an important traditional source food in Bas Congo and can provide much needed protein to the usual diet. Most families find it difficult to get enough protein form other sources. Fish and meat are generally too expensive. Hunting has cleared out most of the larger animals from the bush and even many of the smaller animals, such as the cane rat.
Even caterpillars have become scarce in some areas. The trees they feed on have been cut down or the grass in the savannah burnt, thus killing many of the cocoons which often lie just below the soil surface. Instead of leaving some caterpillars to pupate and breed, all the caterpillars that can be found are usually collected. It used to be the custom that where two or more generations were known to be produced in a season, the first generation was left to pupate. The first crop of Ngala (Cirina forda) caterpillars, for example were said to be "for the birds". Elsewhere if caterpillars were found on branches of trees too high up for the collectors it was also traditional to leave them there, rather than cut the branch down. Unfortunately these safeguards are no longer respected in many villages.
A project was set up to conserve and increase the numbers of edible caterpillars by several villages involved with The Centre de Promotion des Technologies Appropries, a programme run by the Salvation Army at Kasangulu, Bas Congo. The project has involved the collaboration of many people. Local people such as Tata Nganga, Captain Gracia Matondo and Tata Nsimba were instrumental in getting the project started.
The identification of the caterpillars was helped by Rolf Oberprieler and Thierry Bouyer and much of the reference material for the caterpillars was provided by the Edinburgh Royal Museum, U.K. Kibungu Kembelo, Director of the Jardin Botanique de Kisantu, Bas Congo identified the food plants for many of the caterpillars and prepared herbarium specimens which have been lodged with Professor Malaisse, at the National Botanic Garden of Belgium, Meise. M. Kembelo and his staff also located a number of edible caterpillars to provide photographs. The staff of the Programme Apicole/Agricole at Kavwaya also run by the Salvation Army provided assistance in collecting specimens. A major output of the project is a reference Manual for the local people in the Kitandu dialaect of Kicongo. This Manual has clear coloured photographs (some of which are reproduced here) of both the caterpillars and the food plants. Funding is being sought to publish the Manual.
In order to conserve and increase the numbers of edible caterpillars it is important to know how they live, what plants they feed on, and how to protect them (see Table).
1. Caterpillar Life Cycle
Caterpillars start life as an egg laid on a particular plant or tree. It is not difficult to find the eggs of the Ngala species because they are laid in a pile, like a tiny pyramid of white balls, on the new leaves at the end of a Kigala (Crossopteryx febrifuga) tree branch in December. However some species, such as Kaba (Lobobunaea phaedusa), lay their eggs singly so that it is harder to find them.
The eggs soon hatch out and the little caterpillars start feeding. Most moult or shed their old skins five times as they increase in size. Sometimes they change their colour too, like Makedi kedi (Bunaea alcinoe), which changes from brown to red and finally to black in its last stage. Certain caterpillars move down the trunk of the tree on which they have been feeding in order to moult, as is the case with Mvinsu (Imbrasia ertli). It is at this time that they are usually collected for eating.
When the caterpillar has reached its full size it climbs down and pupates in the ground. Certain caterpillars, such as the Nkankiti (Anaphe sp.), form a communal cocoon in the branches of a tree. Traditionally after taking the caterpillars, these sacks were used to keep gunpowder dry when hunting. Normally caterpillars should be disturbed as little as possible, especially when they commence to pupate.
For most species the cocoon remains intact until the start of the next rain season when the moth emerges, usually at night. After mating, the female moth finds a suitable food plant and lays her eggs before she dies. The male dies following mating.
2. Food Plants
Each species of caterpillar lives on certain plants. The Ngala is only found on Kigala trees in Bas Congo. The Mvinsu lives on Kimbaki (Funtumia africana), Kivinsu (Petersianthus macrocarpus), Kinzenze (Holarrhena floribunda) or Kingela (Ricinodendron heudelotii) trees. It is important that there are enough trees of the right kind to provide food for the caterpillars, especially those that only feed on one kind of plant. Where they are not present they can often be planted from seed, or young plants can be collected from below mature trees and transplanted.
3. Protecting Caterpillars
Understanding the life cycle and the food plants utilized by each species will help in protecting and increasing the supply of caterpillars. Ngala is a caterpillar which lives in the savannah and pupates just below the soil surface. During the dry season it is common to burn the grass in order to chase out small rats which may weigh less than 50gm each, but at the same time Ngala cocoons, capable of eventually producing far more than 50kg. of caterpillars, will have been destroyed in the process! If all the Mvinsu caterpillars are taken when they come down the tree trunk to pupate, there will be none left to produce next year's caterpillars. Traditionally the village chief decided when caterpillars could be collected. It is important that his authority is respected and that caterpillars are not taken at other times.
It is important always to leave at least half the caterpillars on the tree to produce sufficient numbers for next season.
Caterpillars will not appear the following year unless some have been allowed to live and pupate this year. It is normal that many caterpillars will be eaten by birds, some will be killed by ants or by parasites. It is important therefore that enough are left to give a good harvest for next year.
A good place for rearing caterpillars is in a forest area which already has beehives. A good strong colony of bees will deter indiscriminate collecting of caterpillars and thus help to protect both the caterpillars and the trees. In this way a permanent reserve will be created where the caterpillars can be carefully managed. If possible it is best to have an area of at least l ha for this purpose. It may be possible to reserve a special area for the beehives for the whole village and this would also be a suitable for raising caterpillars. A traditional "voka" or "nkunku" forest can also form an important reserve for caterpillars and these should be maintained wherever possible.
Caterpillars do not just appear suddenly from nowhere. Nor are they brought by the birds! We each can play our part in making sure that there will be enough caterpillars for tomorrow.
The Jardin Botanique de Kisantu is being supported by BGCI through grant assistance from the Stanley Smith Horticultural Trust.
This article was adapted with permission from Paul Latham from the English edition of his manual 'Edible caterpillars and their food plants in Bas Congo (1999)' which was produced for two rural development projects run by the Salvation Army in Bas Congo, to improve the livelihoods of the local people. Funding is being sought to publish the Manual.