Ethnic heterogeneity of knowledge on Zonocerus variegatus and reasons for consumption and non-consumption in the southern part of Cameroon

With the growth of the human population, non-timber forest products of animal origin, such as grasshoppers, could be an approach to the solution of food shortage. The variegated grasshopper is an edible insect and an agricultural pest in several African countries. This study aimed to evaluate the knowledge, the level and reasons of consumption and non-consumption of this grasshopper in different ethnic groups in the south part of Cameroon. An individual structured survey, conducted from January to February 2018, among ten ethnic groups revealed that 99% of the participants know the variegated grasshopper. It has 22 local names, with mba’assana as the most common name. This grasshopper is mainly used for consumption (93.7%) and the level of consumption is higher among the Mbamois, Bulu, Ntumu, Pygmies and Maka people. It is used as medicine (3.9%), to treat splenomegaly, umbilical hernia, and to prevent rheumatism and benign prostatic hypertrophy. It is also used in traditional rites (0.6%) (Eton) and as a source of income (0.6%) (Ewondo). People consume the variegated grasshopper mainly because of its good taste and high nutritional value (73.24%). The adult is the stage mostly consumed when fried. The Bassa also consume the larvae (6%). Those who refuse the insect mostly talk of its bad odour and that its consumption can lead to the appearance of various pathologies (3.6%) such as cramps, stomach pain, paralysis, allergy, diarrhoea, nerve pain, abdominal pain, poisoning, vomiting and death. The repellent gland could be involved in the toxicity related to the consumption of this grasshopper. For the Bulu people, poor cooking is a risk factor. Further studies are needed on the potential risks of the variegated grasshopper before it could be recommended for general human consumption.

Circadian variation in metabolite and enzyme activities in the femoral and thoracic muscles of adult variegated grasshoppers, Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae)

The African variegated grasshopper, Zonocerus variegatus, exhibits daily variations in its feeding and destructive activities. A study to investigate circadian variation in metabolites (lipids, protein, glucose, K+, Ca2+, Mg2+, Cl−) concentrations and enzymes (lipase, amylase, proteinase, α-glucosidase) activities in the femoral and thoracic muscles of adult Z. variegatus was carried out by collecting samples at 06:00, 12:00, 18:00 and 24:00 hrs GMT. The four enzymes were present throughout the day in both thoracic and femoral muscles but at varying levels. Significantly (p<0.05) higher enzymes activities were measured during the day (between 06:00 and 18:00 hours GMT) (except proteinase) than at night (24:00 hrs). Organic substances in the two tissues were present in significantly higher concentrations during the day than at night. Similarly, significantly more inorganic substances were recorded in the afternoon (12:00-18:00 hrs) than at night in both femoral and thoracic muscles. It can thus be concluded that locomotor activities in Z. variegatus reach a peak during the day.

Consumption of the variegated grasshopper in Africa: importance and threats

Zonocerus variegatus (Orthoptera: Pyrgomorphidae) is a crop pest widely distributed in Africa. It is an insecttraditionally consumed by humans in Africa. It is therefore important to make an inventory on the consumption of Z. variegatus in order to identify its strengths and weaknesses. This literature review shows that Z. variegatus is collected in field crops and fallows and is best consumed after being fried in red oil with salt and pepper. Z. variegatus consumption brings to the human body several organic and inorganic substances such as fats, proteins, minerals and vitamins. However, a cross-section of the African population do not consume Z. variegatus because consumption of this grasshopper is not part of their customs and/or because of rotten-odours rejected by this insect. When disturbed, it secretes a pungent smelly substance that can justify the rejection expressed against this insect bypredators. The rejection of this insect by predators raised the issue of its toxicity. The toxicity of Z. variegatus would be linked to the presence of alkaloids in the body of this grasshopper. Before the widespread consumption of this insect in our societies, it is important to continue research on: (1) the role of Z. variegatus as a vector (transmissionof diseases); and (2) its ability to poison animals and humans. The outcome of these researches, might enlightenus on the role this insect could play in the mismatch that exists today between rapid population growth in Africa and the availability of foods.

Insects as food, traditional medicine and cultural rites in the west and south regions of Cameroon

In Cameroon, non-timber forest products of animal origin, poorly exploited by the population can be an importantsource of food. We carried out a study on the importance of edible insects in five divisions: Koung-khi, High-Plateaus, Menoua (West Region), Mvila, Dja and Lobo (South Region). We conducted individual semi-structured surveys on489 persons, from December 2014 to March 2015. Participants were aged between 8-91 years. Results showed that, nine groups of insects are eaten in the two regions: beetles (89.57%), termites (70.76%), grasshoppers and locusts (49.90%), crickets (44.17%), katydids (42.94%), caterpillars (31.80%), bees (8.38%), variegated grasshopper (8.18%) and ants (6.54%). These insects are mainly consumed: (1) in sauce (caterpillars); (2) fried (crickets, termites, beetles, grasshoppers and locusts, variegated grasshopper and ants); (3) raw (bees); or (4) roasted (crickets). The majority of people (72.49%.) consume insects mostly for their good taste and then for medicinal properties. The intervieweementioned that insects and their products could be used to improve expression in children aged between 2 to 3 yearsand to treat vomiting in infants, rheumatism, chickenpox, spleen inflammation, the large navel, lumbago, mumps, cramps, weak bones. Apart from ants and bees, most edible insects are sold in local markets. Termites (42.94%), grasshoppers and locusts (36.20%), and beetles (34.36%) were the most commercialised. In local markets, they are mostly sold in cups, bottles, glasses or heaps. Ants and bees are sold directly by the traditional healers. Most of theseinsects are harvested throughout the year, except variegated grasshoppers that appears to be seasonal.