Insects are the group of animals that belong to the phyla, Arthropoda. Even though we often see insects as enemies but most of them are highly beneficial to us in several ways that we cannot thrive without them. Interestingly, a majority of them can be consumed or used for therapeutic and medicinal purposes.
Most of these edible species are in high demand as a result of the increasing human population. Edible insects are highly nutritious, healthy and tasty. Among these groups of edible insects that are in high demand are beetles. This post sheds light on some beetle facts that will be of interest to you.
Beetles belong to the order of Coleoptera, with an inclusion of the Curculionidae (snout beetles or weevils). The term Coleoptera is coined from the Greek word “κολεός”, which is pronounced as “koleos”. It literally means sheath and πτερόν, while pteron means wing. In other words, it means sheathed wing.
This is attributed to the fact that most beetles bear 2 pairs of wings i.e. the front pair (elytra) and the rear pair. The elytra normally thicken to protect the rear pair of wings and the beetle's abdomen. Coleoptera can thrive in most natural habitats such as marine habitats, plants vegetation, freshwater etc.
Beetles have been in existence for countless years and they thrive in most ecosystems. Studies reveal that they are the largest order of insects with four suborders namely; Adephaga, Archostemata, Myxophaga and Polyphaga. Different species of beetles can be found in different parts of the world where they survive on trees, decomposing plants, sandy heaths, shrubs, wet soil or animal wastes etc.
Beetles are useful to mankind in several ways; breaking down waste matters, feeding on dead or decaying animals, feeding on leaf litter, aerating the ecosystem, reducing weeds and feeding on crop pests (e.g. ladybird beetle). Ladybirds or ladybugs are very beneficial to the ecosystem because they feed on wide varieties of crop pests (garden beetles).
These insects are the natural alternative to chemical pest control services. In fact, among the lists of beetle diet are; aphids, plant-sucking bugs, mealybugs, mealworms, spider mites, plant lice and sap feeders etc. Notwithstanding the numerous benefits of beetles to humans, it is also important to note that they can be harmful to human beings by damaging houses, destroying food crops, destroying household amenities and beetle infestation etc.
Adult lady beetles are distinguished by their convex, hemispherical to oval-shaped bodies. Different beetle species have different colours such as black, yellow, red, pink or orange with dotted spots on the bodies. The bodies are divided into 3 segments; head, thorax, and abdomen. The exoskeletons comprise of several plates known as sclerites that are separated by thin sutures.
There are different kinds of beetles but some common beetle species include; Coccinellidae (ladybug or ladybird), Callosobruchus maculatus (cowpea seed beetle or cowpea weevil), Xestobium rufovillosum, Tribolium confusum (The confused flour beetle), Tribolium castaneum (red flour beetle),Brontispa longissima, Coccinella septempunctata (European beetle), Callosobruchus maculatus (mungbean or cowpea beetle).
Other beetle species include; Leptinotarsa decemlineata (the Colorado potato beetle), Holotrichia parallela (Scarabaeoidea), Acanthoscelides (bean weevils or seed beetle), Anthonomus grandis (boll weevil), Asian longhorned beetle, cockchafer, dung beetle, bark beetle, click beetle, ground beetles, coconut hispine beetle, Japanese beetle, dune beetle, soldier beetle, powderpost beetle, elm leaf beetle and leaf beetle.
Nutritional Values of Beetles
Yang (2014) examined the chemical composition, fatty acid profile, and amino acid composition of the adult H. parallela beetle. The protein digestibility-corrected amino acid score (PDCAAS) of this beetle was also calculated. The results show that adult Holotrichia parallela Motschulsky contains a high amount of protein (70%), minerals and low fat.
It also contains 10% chitin while the corrected protein content was 66%. Also, a higher amount of linoleic acid and oleic fatty acids were recorded. Out of the total amino acids in this beetle, only 47.4% were essential amino acids. From this report, it is evident that the adult Holotrichia parallela beetle could be a potential source of proteins and minerals for human beings and animals.
Incredible Benefits of Beetles
Beetles are the most popularly consumed insects. They serve as food especially while they are still in the larval stage. It is important to note that not all beetles are edible. So are beetles poisonous? Some beetle species are poisonous while others are not. It is highly advisable to always look out for the edible and non-poisonous ones before consuming them.
Some edible beetles include; larvae of darkling beetle, dung beetles, aquatic beetles, mealworm, rhinoceros beetle, wood-boring larvae, adult of Holotrichia parallela Motschulsky, larvae of Gyrinidae and Hydrophilidae families (Ramos et al., 2009).
N:B - Always allow the beetles to spend at least one day in other to empty their digestive tracts before consumption. Beetles can be prepared and eaten in several ways such as roasting, frying, cooking, boiling or steaming.
DeConconi and Moreno (1988) report that several beetle species have been used as an aphrodisiac in Mexico. An aphrodisiac is anything that can stimulate sexual desire.
The larvae of the Spanish fly Lytta vesicatoria are roasted, mashed and mixed with water. The concoction is then taken to stimulate sexual desires and to treat urogenital disorders.
DISCLAIMER This post is for enlightenment purposes only and should not be used as a replacement for professional diagnosis and treatments. Remember to always consult your healthcare provider before making any health-related decisions or for counselling, guidance and treatment about a specific medical condition.
1] Ademolu K. O., Idowu A. B. and Olatunde G. O. (2010) Nutritional value assessment of variegated grasshopper, Zonocerus variegates (L.) (Acridoidea: Pygomorphidae), during post embryonic development, African Entomology, 18 (2), pp. 360-364.
2] Ajayi F. A. and Lale N. E. S. (2001), Seed coat texture, host species and time of application affect the efficacy of essential oils applied for the control of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) in stored pulses. International Journal of Pest Management; 47(3): pp. 161–166.
3] Banjo, A. D., lawal, O. A. and Songonua, E. A. (2006), The Nutritional Value of Fourteen species of
edible insects in Southwestern Nigeria’, African Journal of Biotechnology, Vol. 5 (3): pp. 298-301.
4] Cabral S, Soares AO, Moura R, Garcia P (2006), Suitability of Aphis fabae, Myzuspersicae (Homoptera: Aphididae) and Aleyrodes proletella (Homoptera: Aleyrodidae) as prey for Coccinella undecimpunctata (Coleoptera: Coccinellidae). Biological Control, 39: pp. 434-440.
5] DeConconi, J. R. E. D. and Moreno, J. M. P. (1988), The utilization of insects in the empirical medicine of Ancient Mexicans, Journal of Ethnobiology 8(2), pp. 195-202.
6] Doley A. K. and Kalita J., (2012), Traditional uses of insect and insect products in medicine and food by the Mishing tribe of Dhemaji District, Assam, North-East India, Social Science Researcher, 1 (2), pp. 11 – 21.
7] Ekop E. A., Udoh A. I. and Akpan P. E. (2010), Proximate and anti-nutrient composition of four edible insects in AkwaIbom state, Nigeria. World Journal of Applied Science and Technology 2: pp. 224-231.
8] Elhag E. A. (2000), Deterrent effects of some botanical products on oviposition of the cowpea bruchid Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) International Journal of Pest Management; 46(2): pp. 109–113.
9] Fereidooni M et al., (2015) Preliminary Data on Life Cycle of Creophilus maxillosus Linnaeus (Coleoptera: Staphylinidae) and New Report of this Species on a Human Corpse, South of Iran. Int J Forensic Sci Pathol. 3(7), 144-147. doi: http://dx.doi.org/10.19070/2332-287X-1500035
10] Hoelmer K. A. and Pickett C. H. (2003), Geographic origin and taxonomic history of Delphastus spp. (Coleoptera: Coccinellidae) in commercial culture. Biocontrol Science and Technology 13: 529-535.
11] Keshavarzi D., Fereidooni M., Assareh M. and Nasiri Z. (2015), A checklist of forensic important flies (Insecta:Diptera) associated with indoor rat carrion in Iran. Journal of Entomology and Zoology Studies 3(3): pp.140-142.
12] Owolabi, M. S., Padilla-Camberos, E., Ogundajo, A. L., Ogunwande, I. A., Flamini, G., Yusuff, O. K.,Flores-Fernandez, J. M. (2014). Insecticidal Activity and Chemical Composition of the Morinda lucida Essential Oil against Pulse Beetle Callosobruchus maculatus. The Scientific World Journal, 2014, 784613. http://doi.org/10.1155/2014/784613
13] Perry, J. C. and Roitberg, B. D. (2005) Ladybird mothers mitigate offspring starvation risk by laying trophic eggs. Behavioral Ecology and Sociobiology 58, pp. 578–586.
14] Ponomarenko, A. G. (1997), New Beetles of the Family Cupedidae from the Mesozoic of Mongolia. Ommatini, Mesocupedini, Priacmini, Paleontological Journal, Vol. 31, No. 4, pp. 389–399.
15] Sarwar M, Saqib SM (2010). Rearing of predatory seven spotted ladybird beetle Coccinella septempunctatal (coccinellidae) on natural and artificial diets under laboratory conditions. Pakistan Journal of Zoology, 42 (1): pp. 47-51.
16] Ramos Elorduy J, Pino JM, Martínez VHC (2009), Edible aquatic Coleoptera of the world with an emphasis on Mexico. J. Ethnobiol. Ethnomed. 5(11): pp. 1-10.
17] Stuart, R. J., Michaud, J. P., Olsen, L. and McCoy, C. W. (2002), Lady beetles as potential predators of the root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae) in Florida citrus. Florida Entomologist 85, pp. 409–416.
18] Wade, M. R., Zalucki, M. P., Wratten, S. D. and Robinson, K. A. (2008), Conservation biological control of arthropods using artificial food sprays: current status
and future challenges. Biological Control 45, pp. 185–199.
19] Yang, Q., Liu, S., Sun, J., Yu, L., Zhang, C., Bi, J. and Yng, Z. (2014), Nutritional Composition and Protein Quality of the Edible Beetle Holotrichia parallela, Journal of Insect Science, 14(1), 139. http://doi.org/10.1093/jisesa/ieu001
20] Zhang M., Haga A., Sekiguchi H., Hirano S. 2000. Structure of insect chitin isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa exuvia. International Journal of Biological Macromol. 27: pp. 99–105.