Entomotherapy: a study of medicinal insects of seven ethnic groups in Nagaland, North-East India

Abstract

Background: The ethnic communities in Nagaland have kept a close relationship with nature since time immemorial and have traditionally used different kinds of insects and their products as folk medicine to treat a variety of human ills and diseases. The present study was conducted to record the entomotherapeutic practices of seven different ethnic groups of Nagaland.

Method: Documentation is based on semi-structured questionnaires and group discussions with a total of 370 informants. The data collected were analysed using fidelity level (FL) and informant consensus factor (ICF).

Results: Fifty species of medicinal insects belonging to 28 families and 11 orders were identified in connection with treatments of at least 50 human ailments, of which the most frequently cited were coughs, gastritis, rheumatoid arthritis, stomach ache and wound healing. Mylabris sp. showed the highest fidelity level (FL) of 100% for its therapeutic property as a dermatologic agent, while the informant consensus factor (ICF) ranged from 0.66 to 1.00. The use of medicinal insects varies amongst the seven ethnic groups, suggesting that differences in cultures and geographic location can lead to the selection of specific insect species for specific medicinal purposes. The largest number of insect species appear to be used for treating gastrointestinal, dermatological and respiratory diseases.

Conclusion: The list of medicinal insect species, many of which are reported for the first time in the present study, suggests the presence of a considerable diversity of therapeutically important insect species in the region and elaborate folk medicinal knowledge of the local ethnic groups. This knowledge of insects not just as a food, but also as therapy is passed down verbally from generation to generation, but is in danger of being lost if not documented in a systematic way. Having stood the test of time, traditional folk medicinal knowledge and its contribution through entomotherapy should not be regarded as useless as it has the potential to lead to the development of novel drugs and treatment methods.

Keywords: Entomotherapy; Fidelity level; Informant consensus factor; Medicinal insects; Traditional knowledge.

Fig. 1

Location map of selected villages for the study (Mozhui et al. [32])

Fig. 2

Graphical representation of the total number of families documented from the study

Fig. 3

Diagrammatic representation showing the percentage contribution by each insect order

Fig. 4

Certain medicinal insect and insect products of Nagaland. a Giant water bug Lethocerus indicus, b dragonfly nymphs, c large timber-boring larvae, d freshly harvested Apis florea bee comb, e, f nest entrances of stingless bees, g Vespa mandarinia comb sold at local market, Kohima district, h blister beetle Mylabris sp., i larvae of antlion Myrmeleon sp., j larvae of Cossus sp., k larvae of banana skipper Erionata torus, l Epilambra sp. cockroach

Fig. 5

Percentage contribution of different preparation methods of medicinal insects

Fig. 6

Habitats of medicinal insects reported in Nagaland

Fig. 7

Diversity of medicinal insects utilized by each tribe

Fig. 8

Order-wise distribution of insect species among the seven tribes