diversity and ecology of wild sericigenous insects in nagaland

KAKATI & CHUTIA 137

Tropical Ecology 50(1): 137-146, 2009 ISSN 0564-3295 © International Society for Tropical Ecology www.tropecol.com

Diversity and ecology of wild sericigenous insects in Nagaland, India

L.N. KAKATI* & B.C. CHUTIA

Department of Zoology, Nagaland University, Head Quarters: Lumami, Mokokchung 798 601,

Nagaland, India

Abstract: This paper deals with the diversity of wild sericigenous insects i.e., silk producing moths in Nagaland, a small mountainous state of north eastern India. A periodic survey conducted during 2004-2006 revealed the presence of 14 species belonging to 8 genera i.e. Antheraea, Actias, Attacus, Archaeoattacus, Cricula, Loepa, Samia, Sonthonnaxia and a large number of host plants. However, only four species are commercially exploited in Nagaland at present and there remains a great scope for producing novel silk from Actias selene, Antheraea roylei, Samia canningi and Cricula trifenestrata. The egg, worm, cocoon and adult stages of certain species have been studied for character evaluation and categorization. The paper emphasizes the importance of these lesser known silk producing insects, causal factors for depletion of population density and advocates for great need for conservation of wild silk moths and their ecological environment in Nagaland. Further, the paper highlights the socioeconomic perspective of rearing and utilizing wild silk moths by the forest dwelling tribal people who could play a major role in conserving these insects and their habitats.

Resumen: Este artículo trata de la diversidad de insectos sericígenos silvestres, es decir, de las polillas productoras de seda en Nagaland, un pequeño estado montañoso del nordeste de la India. Un muestreo periódico realizado durante 2004-2006 reveló la presencia de 14 especies pertenecientes a ocho géneros: Antheraea, Actias, Attacus, Archaeoattacus, Cricula, Loepa, Samia, Sonthonnaxia, y un número grande de plantas hospedadoras. Sin embargo, actualmente en Nagaland solamente se explotan comercialmente cuatro especies y existe un gran campo para la producción novedosa de seda de Actias selene, Antheraea roylei, Samia

canningi y Cricula trifenestrata. Se estudiaron las etapas de huevo, gusano, crisálida y adulto de ciertas especies para evaluar y categorizar los caracteres. El artículo enfatiza la importancia de estos últimos insectos productores de seda menos conocidos y los factores causales de la reducción de la densidad poblacional, y aboga por la fuerte necesidad de conservar a las palomillas de seda silvestres y su ambiente ecológico en Nagaland. Además, el artículo resalta la perspectiva socioeconómica de criar y utilizar palomillas de seda silvestres por la gente de las tribus que habitan en el bosque, quienes podrían jugar un papel primordial en la conservación de estos insectos y de sus hábitats.

Resumo: Este artigo trata da diversidade dos insectos seríceos selvagens i. e., mariposas produtoras de seda em Nagaland, um pequeno Estado montanhoso no nordeste da Índia. Um inventário periódico conduzido durante 2004-2006 revelou a presença de 14 espécies pertencentes a 8 géneros i. e. Antheraea, Actias, Attacus, Archaeoattacus, Cricula, Loepa, Samia, Sonthonnaxia e um número grande de plantas hospedeiras. Contudo, no presente, só quatro espécies são comercialmente exploradas em Nagaland e aí existe uma grande oportunidade para produzir nova seda de Actias selene, Antheraea roylei, Samia canningi e Cricula trifenestrata. O ovo, a lagarta, o casulo e os estágios adultos de certas espécies têm sido

* Corresponding Author; e-mail: [email protected]

138 WILD SERICIGENOUS INSECTS IN NAGALAND

estudados quantos a caracteres de avaliação e categorização. O artigo enfatiza a importância destes insectos produtores de seda menos conhecidos, factores causais para depleção da densidade da população e advoga a grande necessidade de conservação de mariposas selvagens produtoras de seda e do seu ambiente ecológico em Nagaland. Além disso, o artigo dá realce à perspectiva socioeconómica de cultivo e utilização de seda selvagem pelas populações tribais habitantes da floresta e que podem jogar um papel principal na conservação destes insectos e dos seus habitats.

Key words: Sericigenous insects, biodiversity, ecology, conservation, Nagaland.

Introduction

Seri-biodiversity refers the variability in sericigenous or silk producing insects and their host plants (Srivastava & Thangavelu 2005). Non-mulberry silk moths are wild or semi-domesticated “charismatic fauna” which produce lustrous silk and exhibit a great range of variation in life history from egg to adult with characteristically different physiological, morphological and feeding parameters. Fairly good numbers of references are on record about seri-biodiversity and their potential as a source of natural silk in Indian subcontinent (Arora & Gupta 1979; Chinnaswamy 2001; Nassig et al.1996; Srivastava & Thangavelu 2005; Thangavelu 1991; Thangavelu et al. 2002). Arora & Gupta (1979) estimated as many as 40 species in India alone. Jolly et al. (1975) reported about 80 species occurring in Asia and Africa to produce wild silk of economic value. Nassig et al. (1996) has mentioned that the family Saturniidae comprises of about 1200-1500 species all over the world of which the Indian sub-continent, extending from Himalayas to Sri Lanka may possess over 50 species. According to the classification of Lemaire & Minet (1998) it is the largest family of Bombycoidea sensu stricto, containing about 1861 species in 162 genera and 9 subfamilies. The saturniids which include some of the largest and most spectacular species of all Lepidoptera are univoltine to multivoltine depending upon the climatic conditions and are distributed in both temperate and tropical region (Regier et al. 2008).

The North-Eastern region of India makes ideal home for a number of wild sericigenous insects and is centre of wild silk culture including muga (Antheraea assamensis Helfer), eri (Samia ricini Donovan), oak tasar (Antheraea proylei Jolly ) and

mulberry silk (Bombyx mori Linn.) (Peigler & Naumann 2003). However, the diversity of wild sericigenous insects in the region is not fully understood. Given the rapid transformation of original vegetation due to intensive land use practices, it is pertinent to characterize, classify, and document the status of these precious faunal species in the region. While a few survey reports on wild sericigenous insects in the North-Eastern India are available (Bhattacharya & Teotia 1998; Bhattacharya et al. 2004; Thangavelu & Borah 1986; Thangavelu et al. 1987), overall diversity and distribution pattern of wild silk moths in the state of Nagaland are generally lacking. Singh & Chakravorty (2006) enlisted 24 species of the family Saturniidae from North East India, including three species of wild silk moths viz., Antheraea

assamensis, Antheraea roylei and Attacus atlas from Nagaland. But there is no published account on their host plants and life-cycle. Hence a detailed survey of wild sericigenous insects was conducted in the state of Nagaland. Major findings of this study are presented in this paper.

Study area

Nagaland forms the easternmost state of Indian Republic, located between 25°26′- 27°40′N latitudes and 93°20′ - 95°15′E longitudes. It constitutes a part of Indo-Burmese biodiversity hotspot. The state has an area of 16,579 km2 and it is bounded by Arunachal Pradesh in North, Manipur in South, Myanmar in East and Assam in West. The topography of the state is character-istically hilly, at places exhibiting rugged terrain broken by deep gorges and steep slopes. The altitude varies from 199 to 3841 m above mean sea level. Climate is humid sub-tropical to warm

KAKATI & CHUTIA 139

temperate. The mean annual rainfall is ca 2600 mm, with a prolonged rainy season from May to October. The temperature ranges from 12 to 32oC in summer and 5 to 20oC in winter and average relative humidity varies from 67% (March) to 88% (October). Some of the meteoro-logical data viz., temperature, relative humidity, rainfall and number of rainy days collected during the study period from an experimental site i.e. Mokokchung (26°17′N latitude and 94°18′E longitude, 1325 m altitude) are shown in Table 1. The forest cover in the state is about 52% (8,62,930 ha including 1,00,823 ha of government and 7,62,107 ha of private forests) of the total geographical area of 16,57,583 ha. Out of the total forest cover 55.4% is virgin forest, 32.9% is degraded forest and the rest of 11.7% belongs to other category. Despite being the small state, it possesses variety of forest types like tropical wet evergreen forests, tropical semi evergreen forests and sub-tropical broad-leaf wet hill forests distributed throughout the state. The rich floristic diversity of the state is represented by 2,431 species of angiosperm and 9 species of gymnosperm. Nagaland boasts of the tallest rhododendron and the tallest rice plant in the Guinness Book of world records. Besides the state is the repository of herbal medicinal and aromatic plants and rare orchids. Among the variety of wildlife distributed throughout the state, Tragopan blythii (Tragopan), the state bird and Bos frontalis (Mithun), the state mascot are themselves rare species in the world (Anonymous 2005). Over a period of several hundred years, indigenous tribal people of Nagaland have tested, implemented, evaluated, modified and developed several practice of land use pattern like Jhum cultivation, Alder based shifting cultivation, wet terraced paddy cultivation, paddy cultivation through irrigation, Zabro farming system and agro forestry system for their sustenance (Changkija 2006). Being a forest based industry, sericulture in Nagaland may play an important role in

socioeconomic upliftment and forest conservation. Eri culture has been practiced since time immemorial by different tribes and sub tribes in both the plains and the hills of Nagaland. It is mainly done domestically for eri pupae consumption since the pupae have a high protein value and oil. The silk layer is used for production of spurn yarn. While rearing of mulberry silk worm is also practiced in different parts of the state, muga culture is new to the state and not yet popular which may be due to a lack of proper training at the grass root level. Further, inspite of having one research extension centre, the growth and development of oak tasar culture is not encouraging; particularly due to inadequate supply of diseased free laying (dfl) at the farmers level (Kakati 2006). However, in recent years Govt. of Nagaland has imparted sericulture training to farmers and brought about 4148 hectares of degraded/waste land under plantation of host plants of different commercially important silk worm group (Source: Director of Sericulture, Government of Nagaland 2007).

Materials and methods

Extensive surveys were conducted throughout the state of Nagaland covering various seasons and forest types during 2004-2006. The survey objectives were to document the diversity of wild silk moths and to record their distribution as well as host plants. During the survey, officials of the State and Central Sericulture departments as well as other private rearers were interviewed for information on presence/absence of wild silk moths, preferred host plants and attempts at rearing the moths. Natural habitats and undisturbed forests of 11 districts viz., Mokokchung, Tuensang, Kiphire, Zunheboto, Kohima, Phek, Wokha, Mon, Dimapur, Peren and Longleng (Fig. 1) were surveyed for wild silk worms / cocoons / moths and their host plants. The

Table 1. Meteorological data for Mokokchung Field Station (1325 m asl), Nagaland.

Temperature (oC) Relative humidity (%) Season

Max. Min. Max. Min.

Rainfall (cm)

Rainy days (Nos)

Spring (Mar-May) 31.3 16.9 89.8 51.3 73.1 13

Summer (Jul-Aug) 32.2 20.0 90.2 61.7 70.0 22

Autumn (Oct-Dec) 26.5 10.0 87.8 49.9 11.1 04


specimens of moths, worms and their host plants were collected following standard practices and identified with the help of literature (Arora & Gupta 1979; Nassig et al. 1996; Peigler & Naumann 2003) and specialists on the subject from Zoological Survey of India and Botanical Survey of India, Shillong.

Morphometric characterization at different stages i.e. from egg to adult forms was done following Jolly et al. (1979) and Nassig et al. (1996). Four species i.e., Actias selene, Antheraea roylei, Samia canningi and Cricula trifenestrata were reared in natural conditions on their preferred food plants for two consecutive years to ascertain their growth patterns and performance. The effective rate of rearing (ERR) is obtained by dividing numbers of mature worms collected with numbers of worms initially brushed. Cocoons : dfl ratio is calculated by dividing numbers of cocoons harvested with numbers of diseased free laying (dfl) utilized for rearing.

Results

Diversity of silk moths and their host plants

Fourteen species of sericigenous insects belonging to eight genera were recorded from the state of Nagaland. These species along with their host plants and distribution are given in Table 2. The group comprises four species of Antheraea (A. assamensis, A. roylei, A. proylei, A. frithi), two species of Actias (A. selene and A. rhodopneuma); two species of Samia (S. canningi and S. ricini); two species of Loepa (L. katinka and L. sikkima), Attacus atlas, Archaeoattacus edwardsii, Cricula

trifenestrata and Sonthonnaxia maenas (Fig. 2). Of these, Antheraea frithi, Actias rhodopneuma,

Archaeoattacus edwardsii, Sonthonnaxia maenas,

Loepa katinka and Loepa sikkima were collected only at adult stage without confirmation of their host plants. Rest of the species i.e. Antheraea assamensis, A. roylei, A. proylei, Actias selene,

Attacus atlas, Cricula trifenestrata, Samia

canningi and Samia ricini were observed in adult as well as larval stages along with their primary and secondary host plants. Except for a few host plants which are site specific, most are found throughout Nagaland. The wild variety of Antheraea assamensis is also reported from certain areas of Nagaland by earlier authors (Sahu 2005; Thangavelu et al. 1987). According to Peigler (1993) the domesticated eri silk worm (Samia

ricini) is not really a distinct species but a form derived from Samia canningi through centuries of selection for silk production.

Of the 14 species of wild silk moths recorded in the state, biology and economic importance of only three species have been studied so far viz., Antheraea assamensis (Choudhury1983a), Samia

ricini (Chowdhury1983b) and Antheraea proylei (Singh & Singh 1998). It was observed that wild variety of Antheraea assamensis differs in larval and cocoon characters such as colour, weight and size from the semi-domesticated population. The colouration of wild muga moth is chocolate-orange, brown and shining, showing trivoltinism with partial diapause in the pupal stage during winter. There was a wide variation in morphometric characters such as colour, size and weight in different stages of life cycle from egg to adult with specific adaptation and voltinism (Table 3). Attacus atlas moth (wing span of male 191 - 255 mm and female 209 - 274 mm) is the biggest while

Fig. 1. Sericulture map of Nagaland showing different sericulture farm and collecting sites.

KAKATI & CHUTIA 141

Cricula trifenestrata (wing span of male 56-78 mm and female 75-81 mm) is the smallest among all the wild sericigenous insects collected. Except for Antheraea roylei, which forms double layered cocoon, all other silkworms produce single layered cocoons. Cricula trifenestrata was conspicuous by having perforated cocoon.

Growth parameters and performance

Four species i.e., A. selene, A. roylei, S.

canningi and C. trifenestrata were successfully reared at Mokokchung. The biological and cocoon parameters of these species are given in Table 4.

These species, reared for two to three generations in a year showed high volitinism (bivoltine and trivoltine). The shortest period of life cycle of these species during summer season (season II) was correlated with the higher temperature and optimum humidity which ensured faster growth and development in different stages. The larval and pupal durations were longer in autumn (season III) in all the species studied and the extended pupal duration in winter and pre spring indicated the diapausing character of these wild silkworms in their natural habitat. Except for the Actias selene which was trivoltine, other silk moths expressed bivoltinism and Samia canningi remained

Table 2. Selected wild silk moths of the Family Saturniidae, their distribution and host plants.

Species Distribution in Nagaland Host Plants

Antheraea assamensis Helfer

Mokokchung, Wokha, Tuensang, Dimapur (500 – 1500 m)

Persea bombycina Kost Litsea polyantha Juss Litsea salicifolia Roxb. ex Wall Litsea cubeba Pers

Antheraea proylei Jolly Kohima, Phek, Kiphire, Mon, Tuensang, Mokokchung (896-1524 m)

Quercus acutissima Carr. Quercus grifithii Hook f & Thomas Quercus semiserrata Roxb. Quercus incana Linn.

Antheraea roylei Moore Throughout Terminalia myriocarpa Muell. - Arg. Betula alnoides Buch-Ham ex D. Don.

Antheraea frithi Moore Northern region Not known

Actias selene Hubner Throughout Rhus javonica Murray

Alnus nepalensis D. Don. Betula alnoides Buch-Ham ex D. Don. Prunus cerasuides D. Don.

Evodia flaxinifolia Hook

Persea bombycina Kost

Attacus atlas L. Mokochung, Wokha Phek, Zunhebouto (1313-1874 m)

Maesa indica (Roxb.) Wall Evodia flaxinifolia Hook

Cricula trifenestrata Helfer Mokokchung, Wokha, Tuensang, Dimapur (145-1371 m)

Persea bombycina Kost Litsea cubeba Pers Betula alnoides Buch-Ham ex D. Don.

Samia ricini Donovan Throughout

Ricinus communis L.

Heteropanax fragrans (Roxb.) Seem. Evodia flaxinifolia Hook. Manihot esculanta Crantz.

Samia canningi Hutton Throughout

Ricinus communis L. Heteropanax fragrans (Roxb.) Seem.

Evodia flaxinifolia Hook Manihot esculanta Crantz. Duanbanga sonneritoides Roxb. ex DC Anthocephalus cadamba Lamk Litsea salicifolia Roxb. ex Wall

Litsea cubeba Pers

Psidium guajava L.


Fig. 2. Diversity of wild sericigenous insects in Nagaland.

KAKATI & CHUTIA 143

dormant for a maximum period of about eight months from October to mid of May in a year. Observations on the oviposition, hatching of eggs, larval and pupal duration indicated a lower oviposition rate in case of C. trifenestrata which may be due to poor coupling intensity in this species. Hatching of eggs showed uniformity for all species in successive generation except for A. selene which showed less hatching (60%) during summer than other seasons (70%). The larval duration of S. canningi was shorter than other species indicating poor feeding character in this species. However, higher silk content (12-14%)

indicates the efficiency of this species in synthesizing more silk. The effective rates of rearing (ERR %) of all the species in different seasons are satisfactory which indicate scope for commercial exploitation of these wild silk moths in Nagaland. The ERR %, Cocoons:dfl ratio and silk content was highest in S. canningi among all the species but cocoon weight was very low, perhaps due to smaller size. The variability in qualitative and quantitative characters of the cocoon mostly depends upon the type of food plants used for feeding (Sharma et al.1995).

Table 3. Morphological characteristics of certain wild silk moths in Nagaland (All size in mm and weight in g).

Species→ Characteristics ↓

Antheraea roylei Actias selene Samia canningi Cricula trifenestrata

EGG Colour Size LxB Weight

Grayish brown to bluish brown

2.8 x 2.4 0.005-0.009

Gray

2.5 x 2.3 0.004

Brownish to creamy white

1.6 x 1.2 0.001

Ivory white

1.8 x1.2 0.004

LARVA Early Colour Size LxB Weight MATURE Body colour Size LxB Weight

Black

9.4 x 1.7

0.027

Green with bluish tubercles

96.6 x 15.8 12.5-23.1

Chocolate to orange brown

7.2-7.8 x 1.4-1.6 0.03-0.05

Dark green to

light green 78.6-85.4 x 13.8-14

11.4-11.6

Yellowish black

7.1-7.3 x 1.2-1.5

0.01-0.05

Yellowish

69-72.8 x 11.4-12.4 5.5-6.1

Yellowish brown

6.2-6.6 x 1.2 0.029-0.033

Dark brown to pinkish bands

56.4-60 x 7.0-8.6 2.52-2.56

COCOON Colour Size LxB Weight Peduncle size Shell wt. Shell ratio

Doubled layered Whitish

45.4-54 x 24.4-27.4

6.6-11.5 93.2-170.4 0.55-0.80

6.96%-8.30%

Single layered Pale creamish

45.8-58.8 x 21.6-25

6.94-8.70 --

0.29-0.55 5.35%-7.13%

Single layered Gray, orange

brown brick red 35.6-44.6 x 11.8-16.6

1.64-2.69 77-164

0.22-0.40 11.16%-15.75%

Hole present Golden yellow

36-41.6 x 7.2-14.4

0.958-2.01 62.2-93.6

0.102-0.228 8.0%-13.33%

PUPA Size LxB Weight

38.2-45.2 x 18.2-28.6

4.51-11.18

36-55.2 x 9.6-17.4

4.34-9.47

23.4-28.2 x 7.2-9.0

1.41-2.38

22.2-27.6 x 4.8-11.2

0.84-1.78 MOTH Wing expanse Male Female Colour Male Female

132-155 152-175

Greenish gray

Yellowish brown to dull

brown

123-141 156-189

Blue green to chocolate

-do-

115-126 141-155

Dark brown to pinkish white

-do-

56-78 75-81

Orange brown

-do-

VOLTINISM Bi voltine Tri voltine Bi voltine Bi voltine


Discussion

Seitz (1933) recorded 19 species of wild sericigenous lepidopterans from the entire North Eastern India including Sikkim and Assam. Chowdhury (1983a) and Thangavelu (1991) without specifying the limits of survey recorded 10 and 9 sericigenous species respectively from region. The higher record of 14 species (including A. assamensis and S. ricini) in the present study from Nagaland is encouraging as against the findings of the former two authors who might have restricted their survey area in the plains of Assam and foot hills of neighbouring states. Perhaps the natural population of these species has become scarce and extremely restricted in distribution along the hilly areas in the interior forests. The diversity from egg to moth with variations in shape, size and colour among different species show their capacity to adjust to different ecological conditions and reveals the potentiality and genetic adaptability through interaction with environment to struggle and sustain in varying ecological niches. Thangavelu (1991) also revealed that saturniids Antheraea assamensis, A. mylitta and Philosamia cynthia exhibit genetic diversity and natural variations in the wild population indicating natural adaptation to specific niches. Further the existence/distribution basically synchronizes the availability of leaves of food plants (Chinnaswamy 2001).

Analysis of rearing parameters like ERR%, cocoon weight and silk content of four wild sericigenous insects i.e. A. selene, A. roylei, S. canningi and C. trifenestrata indicate a promising future in terms of novel silk with high economic value for the region. While salubrious climatic conditions during spring and summer has assured better production of the cocoons, the diapausing character of these wild silkmoths in their natural habitat indicate their adaptability to severe winters at higher altitudes of the state. Wild silkmoth population comprising diverse gene pool hold great potential utility for mankind. Hence, conservation of this precious genetic resource would be imperative for breeding of better adapted and more desired genotypes. If the reelability of the eri cocoons (Samia ricini) could be achieved through cross breeding with Samia canningi, it could be a breakthrough in the field of eri culture. Further, the genetically useful and important traits of these wild silk moths such as hibernation, reelability may be a sound basis for all future breeding programmes of other domesticated silk moths in evolving commercially and economically desirable improved strains of species (Gogoi & Goswami 1998). Wild silk moth culture not only has an economic bearing on the local inhabitants of North-Eastern India but also helps to save forest ecosystem. Nagaland Pollution Control Board, Government of Nagaland, has reported that deforestation, unsustainable fuel wood extraction, shifting cultivation/jhum, unplanned agricultural

Table 4. Biological and cocoon characteristics of certain wild sericigenous moths in Nagaland, India (Seasons: S1 = Spring, S2 = Summer, S3 = Autumn; ERR = Effective rate of rearing; D = Diapause Period).

Duration (days) Species Season

Egg Larva Pupa Adult

Fecundity (No)

Hatching (%)

ERR (%)

Cocoons/ Dfl

Cocoon wt (g)

Silk content

(%)

Actias

selene S1 S2 S3

15 14 16

32 29 53

26 26 D

7 7 6

236 221 258

70 60 70

46 24 48

77 31 88

6.4 6.3 6.7

6.0 5.9 6.7

Antheraea

roylei S1 S2

14 15

47 66

56 D

10 9

234 282

76 78

30 58

53 128

8.0 9.0

8.0 7.6

Samia

canningi

S1 S2

11 13

27 29

24 D

7 7

300 283

79 73

54 51

129 104

2.0 2.0

12 14

Cricula

trifenestrata S1 S2

13 15

44 51

18 D

6 5

83 81

71 70

45 32

26 18

2.0 1.0

9.0 10

Actias selene = From December to mid of March, Antheraea roylei = From January to May Samia canningi = From October to mid of May, Cricula trifenestrata = From December to June

KAKATI & CHUTIA 145

practices, encroachment into forest land for agriculture and settlements, forest fire, over grazing, non-adoption of adequate soil conservation measures and improper crop rotation are some important factors contributing to loss of vegetation and land degradation in Nagaland. Shifting cultivation is the major cause of wastelands in Nagaland. This would have direct impact on food plants of different wild silk moths. Diversity of sericigenous moths needs to be conserved through well planned and sustainable use of natural resources. Proper eco-development measures and strategies for ecological restoration of degraded jhum fallows would be needed to ascertain the continued existence of the valuable entomofauna among other components of biodiversity (Mohanty 1998). Exploration and evaluation of different species /subspecies /races and their genetic improvement through selective breeding would also go a long way in development of age old science of sericulture in the region. Increasing urbanization, lopping of trees and lack of awareness about wild silk worms and their host plants among the local farmers are likely to result in local extinction of few species. Therefore, there is a need to initiate conservation awareness programmes for the local communities in the state by introducing the concept of silkmoth farming, the practice of which not only provides substantial economic gain to tribal people but also helps to conserve forests and regional biodiversity. Wild silkmoth farming (sericulture) as a cottage industry offers many advantages to poor communities, in that it requires minimal expenditure when compared with other agricultural endeavours; it is labour intensive and suitable to the rural farmer. Hence, efforts are needed to revitalize the age old tradition of non-mulberry sericulture especially in the tribal belts. Conservation of wild population of sericigenous moths is much easier than that of domesticated ones provided it can be carried out in-situ (Frankel 1982). This would ensure protection of forest wealth by utilizing the available food plants for rearing thereby, generating revenue for the inhabitants rather than using forest resources for fuel and timber only and also improvement in genetic variability of indigenous silk moth population by developing improved hybrids (Bhattacharya & Teotia 1998). Efforts should also be made for ex-situ

conservation, protection and proliferation of wild

silk moths through planned and collaborative efforts of state and central government agencies through formation of Task Force comprising scientific and extension personnel on systematic and scientific lines (Naqvi et al. 1998). Encouragement of traditional skills such as maintenance of sacred groves close to villages, rewarding local conservators and organization and management of eco-tourism would greatly help the conservation programme (Sahu & Bindroo 2007).

Acknowledgements

The authors express thanks to the G.B. Pant Institute of Himalayan Environment & Development, Almora, for financial assistance through a research project sanctioned to Dr. L.N. Kakati.

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