The consumption of caterpillars is a part of the country’s cultural heritage and has been practiced over many generations. The study showed that E. lactea is most preferred caterpillar compared with L. saturnus and C. hyperbius thereby confirming previous findings [7, 9, 16]. This study showed also that E. lactea pupae have a better taste, which accounts for the higher preference. Nutritional analysis of E. lactea by Malaisse in the 1970s revealed a lipid content as high as 29.6%, more than twice the values reported for most other caterpillar species. It is also a significant addition to the protein supply of rural people.
Pupae are more preferred than caterpillars. In that regard, Malaisse [16] demonstrated already that the absence of the digestive content in the pupae would give them a pleasant taste, giving the consumers an outstanding gustatory quality. Taste, texture, and visual appearance were all highlighted by Ghosh et al. [17] as important determinants of an edible insect’s acceptability as a food item for human consumers. Besides, consumers indicated that better appearance makes it less frightening compared with other caterpillars.
The indicators of the harvesting season of caterpillars in the Plain of Lubumbashi are mainly the presence of damaged leaves and the level of humidity in conjunction with the abundance of food plants (and also the bushy aspect of the canopies). Information on the presence of caterpillars is verbally disseminated across the region; hence, climate plays a vital role as an indicator of the E. lactea harvesting season, as indicated by Malaisse [18].
The E. lactea lifecycle is 12 months (from December to November). The period of incubation is about 1 month (from mid-January to mid-February), the larval stage is 4 months (from mid-February to mid-May), the pupal stage is 6 months (from mid-May to mid-November), while the adult stage is 2 months (mid-November to mid-January). This corroborates previous reports [18, 19], except that in this study, it was found that E. lactea life cycle shifted by 1 month earlier. It is suspected that the shift in the lifecycle might be due to recent changes in climatic conditions that are currently taking place in the Miombo ecosystem. These changes are mainly due to anthropogenic activities (mining, constructions, farming, overexploitation), which result in habitat changes that the insects are exposed to [20].
In this study, several factors were found to affect trade, including distance (to market or harvesting site), the potential value of the market, number of transactions, stage (taste), transport, and number of intermediaries (wholesalers). The harvesters and the collectors move to the sites on foot and use several techniques and tools for harvesting, including sticks, branches, and tablespoons.
The displacement from households towards the areas of harvest is achieved on foot or by bicycle. These two means of transportation help the harvesters go farther into the forest where vehicles cannot reach. Dikumbwa and Kisimba [20] demonstrated that the quantity of caterpillars harvested is a function of the transport means used. The longer the distance between the households and the points of harvest, the fewer the caterpillars. The latter fact differs from the quantity harvested close to households where the entire community, including men and children, are involved in the collection of caterpillars.
Besides the long-distance accomplished by harvesters, the methods of E. lactea harvesting are rudimentary. In most cases, harvesters use pieces of wood that they find in the sites of harvest, especially when harvesting takes place at long distances (between 20 and 45 km). Caterpillar harvesters are hardly ever keen to change collection sites. They are sedentary and rarely to move from one village to another, or from one site to another, even in the case of the disappearance of the caterpillar [20]. This explains, at times, the presence of caterpillars in some villages yet none in others. Production is not always quantified. It is rare that harvesters can provide an exact number in terms of kilograms of caterpillars harvested. This can be ascribed to the low level of education and lack of initiatives observed in these sites.
Pupae harvested in the off-season are highly praised, as mentioned above, due to their pleasant taste. For the case of E. lactea, the pupae are more preferred than the caterpillars. As a commodity, the higher the supply, the lower the price and vice versa.
Irrespective of the season, the income of caterpillar harvesters in the Plain of Lubumbashi is always lower than the minimum universal average wage, as per the indicators of human development [22].
The harvesting rates of caterpillars not only vary according to the types of players involved, but also the period of production. The month of March, with the presence of rains, brings the production of several other food commodities, including other edible insects, which put the caterpillars of E. lactea under immense competition with other foods. This also explains the variations of prices in the sites of production and consumption. Also, during the off-season, with a decrease in the production of many food commodities on the one hand and of the excellent taste of the E. lactea pupae on the other, the latter is sold at more elevated prices than during the period of full production of the larvae at the sites.
There is a range of harvesters, and this activity is not assigned to only a specific group or community. The first group of people harvest caterpillars while producing coal. The second group only collects caterpillars, while the third group harvests caterpillars only occasionally during their passages through the forest. The diversity of harvesters also implies heavy pressure on the availability of the insect.
The trade in E. lactea has in the past been interrupted due to the temporary disappearance of the insect in 2004 in the Plain of Lubumbashi. It reappeared in 2005. This is due to many factors: the region is generally populated by Bemba communities, native to the Plain of Lubumbashi, who are basically not farmers and therefore exploit the Miombo forest for primary needs. Therefore, the slashing of trees for charcoal production is a prevalent practice, and it is associated with caterpillar harvesting in the region, as reported by Dikumbwa and Kisimba [20]. Malaisse noted the dependency of this species on Miombo forest biomass and suggested forest protection policies. At the same time, he denounced the invasion of the E. lactea habitat by anthropogenic activities [10]. Concerns on Miombo forest decline have been raised in several countries sharing this biome and the potential decline of edible caterpillars [7, 8]. The forest indeed contributes to the livelihood of millions of people; therefore, there is a need to develop a strategic plan to sustain the ecosystem services [21]. Further research on the relationship between forest decline and the availability of E. lactea would be crucial for the future of this insect in the Katanga region. The research will use historical data on forest cover, remote sensing, and mapping to illustrate the magnitude of the decline to guide the decision.