Aquatic edible insects of Loktak Lake of Manipur, North East, India

M. Bhubaneshwari Devi, O. Sandhyarani Devi and S. Dineshwor Singh *

ABSTRACT

The edible insects viz., Lethocerus indicus, Diplonychus rusticus, Gerris sps, Aquarius sps, Limnogonus sps, Enithare sps, Paranisops sps, Cercomatus sps, Libulla sps, Sympatrum sps, Leucorrhina sps, Ischnura sps, Pseudagrion sps, were present in the natural habitat of Loktak lake. Survey revealed a total of 31 aquatic insect species belonging to 4 orders, 12 families and 27 genera with food value.

The order Hemiptera has the maximum numbers of edible species (14) and least number (1) in Ephemeroptera.

INTRODUCTION

The aquatic edible insects constitute a very important food source in many countries and Manipur also. They are good source of high content of proteins, fat, carbohydrates, mineral and vitamins (Ene 1963, ASHIRU, 1988, Defoliart 1988-1991). Aquatic edible insects are a natural renewable resource that provides food to many ethnic groups of many countries.

In the North Eastern India particularly Manipur, Assam and Nagaland, aquatic insects like Giant water bugs and water beetles have a high market demand. The inhabitants of the Loktak Lake market demand. The inhabitants of the Loktak Kake have a natural source of earning money through the use of 17 species of aquatic insects as food and also used for fishery.

Gope and Prasad (1983) reported that insects represent the cheapest source o f animal protein in Manipur. Most of the tribal people of Manipur and Assam are also habituated with the consumption of giant water bug. Hazarika (2008) reported the high market demand of giant water bug in some lower Assam.

In Manipur the market price of giant water bugs is more than Rs 30 per one bug. Nowadays this bug is not found abundantly. Around 10-20 bugs were found sold at the Khwairamband Bazar in a particular area of the market by an old women according to the market survey of present study.

The population of this bug is now in danger due to the application of pesticides in the paddy fields as well as in the loktak lake by fishermen while catching fish. Therefore, it is highly needed to study the bio-ecology of these bugs particularly in Manipur. Regarding to this fact the present study was undertaken for the conservation and management of these giant water bugs.

MATERIALS AND METHODS

The present study was carried out during April, 2012 to December 2012 as a part of the MOEF funded project. Intensive survey was conducted in the different 12 sites of Loktak Lake. The aquatic insects were colonized on the littoral and limnetic zones of the lake. These were collected by sweeping into an insect net.

Different markets were also visited for collection of different aquatic insects and collected information. The Loktak lake lies between 240 25’N to 240 40’N latitude and 930 45’N to 930 40’N Longitudes. The survey work was conducted in 12 collection sites. It covers a total geographical area of 286 km2. The Loktak lake was inhabited by Meitei community.

Survey and historical review of the aquatic edible insects revealed that the insects were collected day by day by the inhabitant of the Loktak lake for food and sold in the market for their needs.

RESULTS AND DISCUSSION

The extensive survey and the information data revealed the occurrence of 17 species belonging to 12 families and 27 genera consumed by the ethnic groups of Manipur. The Hemipteran order shared with the maximum number of 14 species followed by Odonata by 9 species, Coleopteran by 6 species respectively. Details about their specific name, local name, modes of consumption, stage of consumption etc. were provided in Table 1.

The larvae (nymphs) and adults of Cordulidae sp., Libulla sp., Sympatrum sp., Leucorrhina sp., Ischura sp., Pseudogrion sp., consumed by almost all the ethnic communities in their region in various forms.

Nymphs/grubs and adult stages are mainly eaten in order Hemiptera and Coleoptera. Majority of ethnic groups consumed the insect in roasted, boiled and dry fry or fry in oil. Preparation of dry and wet chutney using giant water bugs, Lethocerus indicus and water beetles such as Cybister sp. and Hydrophilus olivaceous, etc. were known in Manipur.

In the present investigation, the survey of the selling of the insects in the local market of Manipur has been observed especially in the Imphal East, West, Bishnupur and Thoubal districts. Giant water bug was sold @ 10-50 per live individual.

The market value of this said item varies from district to district and again season. Consuming of the aquatic insects in an age old tradition and well accepted socio-cultural attribute for the ethnic groups of Manipur.

The use of insect as human food especially by indigenous people in the other part of the world was well documented. But such investigation pertaining to the Loktak lake of Manipur is far lacking.

The documentation and scientific publication in the recent part such as Meyer Rochow (2004), Singh, et al. (2007), Singh and Chakravorty, (2007 and 2008), Kato and Gopi (2009), Ronghang and Ahmed (2010), Singh, et al. (2012), Shantibala et al. (2012), etc. are worth mentioning.

People of Thailand have been eating insects for centuries. In particular, a traditional well known delicacy is the giant water bug, Lethocerus indicus which is used to make namprik maeng daa, a common Thai (Hanboosong, 2010).

A collective approach on scientific documentation of the traditional knowledge and technique used by different ethnic groups of Manipur is the need of the hour especially to conserve the dwindling entomofauna of aquatic edible insects and also to introduce such products commercially to enhance economy of the ethnic communities in a sustainable way.