Mopane Worms

Scientific Name and Classification

Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Saturniidae
Genus: Imbrasia
Species: I. belina (Westwood, 1849)

A Mopane worm is the 5^th larvae stage of the emperor moth species. It is perceived as a large caterpillar. The name Mopane worm came by because of their characteristic habit of feeding on the Mopane tree (Colophospermum mopane). The worm's scientific name is Imbrasia belina of the Emperor moth (Gonimbrasia Belina) species. The Mopane worm has different common names depending on the local tribes.

Table 1: Different names of Mopane worms in Southern Africa

Origin and distribution of mopane worms

Mopane worms are native to warmer parts of Southern Africa; very common in semi-deserts, bushveld and grassland. Mopane worms are broadly considered by the indigenous people as a delicacy. Mopane worms are distributed throughout Angola, Botswana, Namibia, Mozambique, Malawi, Southern Zimbabwe, Zambia, Democratic Republic of Congo (DRC) and Northern South Africa (see Figure 1). Its distribution is close enough but not basically restricted to Mopane trees (Colophospermum mopane) and habitats spreads over approximately 384 000 km² of forest (FAO, 2003). However, environmental drivers and factors influencing mopane distribution are largely based on the: (Mataboge et al., 2016 and Makhado et al., 2014)

• Rainfall - the relationship between high rainfall and the mopane worms is negative; low rainfall positively correlates with the distribution of mopane worms and as an annual rainfall exceeds certain amount, the relationship becomes weaker.
• Temperature - the temperature ranges between 18-24˚C in South East Lowveld of Zimbabwe. An average maximum temperature associate best with the distribution of mopane worms and the relationship drops when the temperature drops which then makes it a positive relationship. A minimum temperature of less than 5˚C limits their distribution (Stevens et al., 2014)
• Altitude - it is reviewed a positive relationship however as mopane worms distribution is best associated at low altitude, it can decline at high altitudes.
• Soil type - although mopane worms survive on different soil types (sandy-loamy, fine-grained soil etc.) it is mostly associated with shallow soils which lack nitrogen, phosphorous, moisture and exchangeable
  magnesium as it favours its growth and performance.
• Ordination of Mopane distribution.

Like other worms, mopane worms are voracious eater until it undergoes metamorphosis. The mopane caterpillar shares its primary food source, the mopane tree, with elephants (FAO 2013).

Description and Reproduction

The Mopane worm is primarily peppered black in colour with round scales alternating whitish green and yellow bands, and armed with short black or reddish spines covered in fine white hairs.

Like most caterpillars, the Mopane worm’s life cycle starts when it hatches in the summer, after which it proceeds to eat the foliage in its immediate vicinity. As the larva grows, it moults 4 times in its 5 larval stages, after which the Mopane worm is considered most desirable for harvesting (for the pot).

The mopane worms are bivoltine and produces two generations every year the first one between November and January and second one between March and May (Stack et al., 2003; Ghazoul, 2006).

According to the reproduction of Mopane worms; the moths are reviewed to be large with 120 millimetre wingspan. Male moths have feathery antennae purposely used to find a mate as they can detect the presence of a female moth. In addition, this however is a means of communication between a male and a female moth. After the hatching of mopane worms in summer, the growing caterpillars’ feeds from the foliage of the tree it was hatched on until the tree is demolished and they move to the nearest tree with foliage to eat.

Nutritional and economic benefits of mopane worms

The Mopane worms are classified as non-timber forest (NTF) products and serve as a source of food security and cash income for the people living in the vicinity of mopane woodlands (Oppong, and Senyolo 2016). They provide employment opportunities and income generation for rural communities. On an annual basis, approximately 9.5 billion mopane worms are harvested with an estimated value of US$85 million (Ghazoul, 2006).

Mopane worms are considered by Zimbabwe and other parts of Southern Africa as the staple part of diet. The mopane worms are the most consumed caterpillar in Southern Africa thus contribute to nutritional security. They can be eaten dry and crunchy like potato crisps or cooked and drenched in sauce. For example, approximately eight (8) million people in Kinshasa the capital city of DRC consume mopane worms for nutritional benefits and taste (Latham, 2003; Vantomme, Gohler and N’Deckere-Ziangba., 2004). Furthermore, mopane worms provide rural communities with 61% crude proteins, 17% crude fats and carbohydrates higher energy value than beef, fish, lentils, beans that are usually lacking in their staple food (Banjo, Lawal, and Songonuga, 2006). The Mopane worms serves as a good source of calcium, zinc and iron (Glew et al., 1999).

In order to reduce malnutrition, certain communities feed children flour made from dried caterpillars whereas pregnant; breast feeding and anemic women eat caterpillars for increasing protein, calcium and iron levels (FAO, 2004). Most importantly, entomologists further researched that Mopane worms can be used to help the AIDS and HIV- positive people by improving their immune systems (Toms et al., 2003). It is an advantage for people living inthe areas where mopane worms are abundant, as these worms offer them a cheap source of protein as opposed to their counterparts who have no access to the worms.

Trading of mopane worms

Local communities engage in trading activities of mopane worms as a source of livelihoods. The trading component serves as an incentive for harvesting and contributes significantly to household incomes (Stacket al., 2003). Firstly the women and children collect the mopane worms by hands, de-gut (Figure 3), and boil them in salty water, before lastly sun-drying them (Figure 4). Dried mopane worms have a long shelf-life of up to a year ideal for the rural communities whereby refrigerators do not exists (Dube and Dube 2010).

Majority of the mopane worm traders are found in towns (open markets, bus termini etc.). Most often, the small enterprises are run by women while the men control the long distance big market chains due to the large volumes being traded (Kozanayi and Frost, 2002).

(Kozanayi and Frost 2002) explained how the following attributes: form, location, concentration, and availability period informs the value addition of the mopane worms throughout the value chain. The same authors explained that firstly, value is added when mopane worms are harvested and processed and that this changes it’s the form and concentration. Secondly, the processed worms are sent to the consumer markets by the collectors themselves or the intermediate traders/ middle man to the wholesale markets. These add value as the product is available in the consumer markets. Thirdly wholesalers usually repackage the worms intro smaller packed which are often sealed and labelled for sale in the formal sectors such as shops and supermarkets alternatively they sell in bulk directly to the retailers in informal markets. Retailers may purchase the stocks from intermediate traders. Among small traders value is often added by cooking mopane worms with spices for consumption by consumers.

The mopane worms are also exported to international markets in Europe. The target market is the African diaspora living in countries such as France, Belgium, United Kingdom etc. (FAO, 2013). For international markets, mopane worms are usually canned and packed in sealable pouches (Figure 5 and 6).

Diseases

The mopane worms are more vulnerable to viral and bacterial diseases in captive breeding and as a results farming should be kept at a small scale to limit incidence of viral diseases. Parasitoids are common to wild populations of mopane worms. More research on diseases and parasitoids is required for farming practices and also would be beneficial to the local communities (Ghazoul, 2006).

Rules and regulations

There is limited regulatory frameworks governing the insects as a source of food and feed globally (FAO, 2013). The worm is becoming extinct in Southern Africa due to overharvesting (Saunders, 1994). As a results Zimbabwean authorities introduced permits for harvesting timber and non-timber products Gonarezhou National park and rules were non-existent in other parts of the resettlement areas (Mufandaedza, Moyo and Makoni 2015). Furthermore, in Gonakudzingwa Small Scale Farms has to request for permission from the farm owner prior to harvesting of mopane worms.

References

1. Baiyegunhi, Lloyd, B B. Oppong, and Grany Senyolo. 2016. Socio-Economic Factors Influencing Mopane Worm (Imbrasia Belina) Harvesting in Limpopo Province, South Africa. Journal of Forestry Research. Vol. 27.
2. Banjo, A D, O A Lawal, and E A Songonuga. 2006. "The Nutritional Value of Fourteen Species of Edible Insects in Southwestern Nigeria." African Journal of Biotechnology 5 (1684–5315): 298–301. doi:10.5897/AJB05.250.
3. Dube, S, and C Dube. 2010. "Towards Improved Utilization of Macimbi Imbrasia Belina Linnaeus , 1758 as Food and Financial Resource for People in the Gwanda District of Zimbabwe." Zimbabwe Journal of Science and Technology 5: 28–36.
4. FAO. 2013. Edible Insects. Future Prospects for Food and Feed Security. Food and Agriculture Organization of the UN. Vol.171.doi:10.1017/CBO9781107415324.004.
5. Kozanayi, W, and P Frost. 2002. Marketing of Mopane Worm in Southern Zimbabwe.
6. Mataboge, Mamakwa Sanah, Fumulani Mavis Mulaudzi, Friedeburg Anna Maria Wenhold, Phillip Obed Yobe Nkunika, Nomusa Rhoda Dlamini, and Robyn Gwen Alders. 2016. "Effects of Climate Variability on the Harvesting and Preservation of Mopani Worms." Linga Indilinga African Journal of Indigenous Knowledge Systems 15 (2): 34–38.
7. Mufandaedza, Edward, Doreen Moyo, and Paul Makoni. 2015. "Management of Non-Timber Forest Products Harvesting: Rules and Regulations Governing (Imbrasia Belina) Access in South-Eastern Lowveld of Zimbabwe." African Journal of Agricultural Research 10 (12): 1521–1530. doi:10.5897/AJAR2013.7720.
8. Oppong, C.K., Addo-Bediako, A., Potgieter, M.J. & Wessels, D.C.J. 2009. Distribution of the eggs of the mopane psyllid Retroacizzia mopani (Hemiptera: Psyllidae) on the mopane tree. African Invertebrates 50 (1): 185-190.
9. Saunders M. 1994. Saving the Mopane Worm. The Washington Post, Sept.1 1994 pp. 33
10. Stack, J., Dorward, A., Gondo, T., Frost, P., Taylor, F. & Kurebgaseka, N. 2003. Mopane worm utilization and rural livelihoods in southern Africa. Paper presented at International Conference on Rural Livelihoods, Forests and Biodiversity, 19–23 May, 2003, Bonn, Germany
11. Stevens, N., Swemmer, A.M., Ezzy, L. & Erasmus, B.F.N., 2014. Investigating potential determinants of the distribution limits of a savanna woody plant: Colophospermum mopane, Journal of Vegetation Science 25, 363–373.
12. Toms RB, Thagwana MP, Lithole KD. 2003. The Mopane Worm-Indigenous Knowledge in the Classroom, South Africa.
    PMCid: PMC1964420
13. Vantomme, P., Göhler, D. and N’Deckere-Ziangba, F. 2004. Contribution of forest insects to food security and forest conservation: The example of caterpillars in Central
14. Africa. Odi Wildlife Policy Briefing, 3.

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