ON A COLLECTION OF LEPIDOPTERA FROM THE NEORA VALLEY AND VICINITY, WEST BENGAL, INDIA

The Zoological Survey of India delegated a six-member group including the author to an expedition at the Neora Valley and vicinity. The other participants were from the Dept. of Botany, University of Calcutta, Kalimpong (Spl.) Forest Division, West Bengal, National Medical College, Calcutta, and the Signal Regiment of the Mountain Division, Eastern Command. The expedition, led by the Calcutta Section of Himalayan Club, lasted from 20th November to 12th December, 1982. The object was to gain basic information about the flora and fauna of the region, in addition to practical information relating to its sociology and medical and defence requirements. The Neora Valley and adjacent Murti Valley are located in the Kalimpong subdivision of Darjiling district, West Bengal, between 27°5'N and 88°45'E in the East Himalaya. The Neora Valley has previously been surveyed mainly along its eastern ridge, by explorers from the Forest Development Corporation, West Bengal, in 1979, and jointly by members of the Z.S.I. 'and Botanical Survey of India in 1981. The interior of the region was only reached, with considerable hardship, for the first time in 1982, via the western ridge. The Neora Valley well deserves its recognition as one of the most important Biosphere Reserves in India. The present work gives an account of the faunistic survey carried out, and general climatology of the area visited. It gives an inventory of the Lepidoptera encountered, together with comments on their zoogeography. Some material collected by the earlier survey party of Z.S.I. is included. An Appendix giving details of material data and a route map are provided. Neptis mahendra samsinga, ssp. nov., is deocribed and compared with its allies from literature cited in the paper. All the specimens including the holotype of the new subspecies are in the Z.S.I. Repository.


INTRODUCTION
The Zoological Survey of India delegated a six-member group including the author to an expedition at the Neora Valley and vicinity.The other participants were from the Dept. of Botany, University of Calcutta, Kalimpong (Spl.)Forest Division, West Bengal, National Medical College, Calcutta, and the Signal Regiment of the Mountain Division, Eastern Command.The expedition, led by the Calcutta Section of Himalayan Club, lasted from 20th November to 12th December, 1982.The object was to gain basic information about the flora and fauna of the region, in addition to practical information relating to its sociology and medical and defence requirements.
The Neora Valley and adjacent Murti Valley are located in the Kalimpong subdivision of Darjiling district, West Bengal, between 27°5'N and 88°45'E in the East Himalaya.The Neora Valley has previously been surveyed mainly along its eastern ridge, by explorers from the Forest Development Corporation, West Bengal, in 1979, and jointly by members of the Z.S.I. 'and Botanical Survey of India in 1981.The interior of the region was only reached, with considerable hardship, for the first time in 1982, via the western ridge.The Neora Valley well deserves its recognition as one of the most important Biosphere Reserves in India.
The present work gives an account of the faunistic survey carried out, and general climatology of the area visited.It gives an inventory of the Lepidoptera encountered, together with comments on their zoogeography.Some material collected by the earlier survey party of Z.S.I. is included.An Appendix giving details of material data and a route map are provided.Neptis mahendra samsinga, ssp.nov., is deocribed and compared with its allies from literature cited in the paper.All the specimens including the holotype of the new subspecies are in the Z.S.I.Repository.

SAMSING
West Nar, extends from the Pankhasari Block at a higher elevation in the north through Sakham down to Garubathan, leading to Kalimpong.Its eastern boundary, the East Nar, originates from a point beyond the Thosam Chu and emerges at Samsing off the Murti Valley in the south.The Murti Valley is linked by an abandoned mu1etrack across the upper reaches with Rechi La at the further north of Labha (a small forest village having a temporary market).At the Rechi La Chowk, the hill tribals cultivate potato crops in season and sell at Labha.There is no permanent settlement at the Rechi La Chowk, where grazing occurs during summer months, up to its lower reaches.The land belongs to the Forest Dept., Govt. of West Bengal, and is leased to F.D.e.L.
Topographically a 'V'-shaped valley, the area is extremely rugged, with high hills dissected by deep ravines and gorges covered with thick plantations.Throughout its extent, there are long ridges, and precipices of varying heights.Prolific undergrowth is also no less uncommon in many places, including near the bed of Neora Valley in particular.The hill stream, locally called 'Neora Khola', flows torrentially.Open meadows or steppes are hardly visible from both the upper and lower reaches.The forest canopy is too thick to allow the penetration of sunlight to the floor.Scattered kraging in the lower reaches has been carried out,•for constructing forest roads and dams, installing waterpipes, for shifting cultivation and so on.However, the centrally rugged terrain offers a safe haven for much wildlife, including butterflies and moths.
As to the riverine system, it may ~e noted that amongst the eight major rivers flowing in North Bengal, three drain the Neora Valley and vicinity.Extending from west to east, in turns, the river Chel, about 55 kms.long and 90-150 m. wide, arises from the Pankhasari Block and flows along the West ~lar.The River Neora, about 60 kms.long and 90-125 m. wide; arises from the Rechi La Chowk below its ridge (= 'danda', as locally known) and flows through the central zone but inclined to the West Nar.The River Murti, about• 20 kms.long and 30-60 m. wide, arises from the Thosam hills and flows along the East Nar.Of these, the longest river Neora has a catchment-basin of about 135 sq.kms.and is reported to have its maximum discharge of water amounting to about 12,000 cusecs and the minimum, 23 cusecs.

CLIMATE
The wide range of altitudes is responsible for the marked climatic differences observed in the region.The conditions vary from tropical to temperate or even subalpine, in accordance with the elevation of the area.At Rechi La (0 3,000 m.), the snowfall was 30.50-61.00 cm.during 24 hours at the time of visit by the team.The rainy season prevails from the m~ddle of May to October.Similarly, due to the topography, the annual rainfall varies from 225-750 cm.; in the catchment area it averages 625 cm.At further lower reaches, for example, at Mo Chowki and Samsing in the East Nar forest block of the Kalimpong Forest Division, the approximate annual rainfall varies from 450-500 cm.

TREKKING
The course of trekking route (viae fig. 1) by the latest team, including the author, is briefly described.On this occasion the team started at the higher altitude, not the lower, as in the Indian Tons Valley Expedition (vide Mandai, 1984).
Trekking started on Nov. 23 from the Pankhasari Block, about 8 kms.north of Labha, at 0 2,400 m.The foot-track was followed along a distance of c 5 kms.northwards to the Rechi La Chowk at an altitude of 0 3,000 m., where the team had to make two nights' halt in a cow-shed temporarily used by the local people.From here, a distance of 0 24 kms.was traversed on the way to Jorpokhri towards the Rechi La Peak and back.Jorpokhri (0 3,100 m.), a spot with a couple of natural ponds, is near the Rechi La Peak, the highest point in the area along the Pankhasari-Rechi La ridge.From here, the team statted moving downwards and southwards, mostly along the ridge of the Neora.The members first arrived at an unknown destination on a trek of 0 5 kms.and pitched tents under the shade of Rhod,oaenaron at 0 2,200 m.They left for the next camp at an almost similar distance, the locality of which was also unknoY/D at 0 2,000 m. under the shade of Echinocarpus.The next camp was at Doban, where the Rivers Neora aDd Thosam are confluent.The terrain is too steep to negotiate and marked by a fairly large rocky cave (named by the leader of the expedition as 'MandaI Cave').In one stage, fixed rope was used to negotiate the foot-track across a high waterfall.The next camp was at Bhanjan (0 2,000 m.) which was reached after 15 km.-march amidst the shade of very tall Maple trees.From here, the members split up into a couple of subgroups: the smaller group proceeding westwards, while the other, including the author, southwards to reach the next camp at Mo Chowki (0 1,500 m.) where it lodged at the Beat House after traversing a distance of 8 kms.The final leg of the trek ended at Samsing (c 350-650 m.), where these members arrived after traversing a further distance of 8 kms.They had to await the smaller party in the Forest Rest House at Samsing, forming the exit from the dense forest, for four days.This was a worrying time, finally relieved by a happy reunion on Dec. 9.
The entire team did their best to gather data for their respective disciplines, especially in the Neora Valley.But the trekking was very tough.The team covered an overall distance not less than 60 kms. in 13 days, over difficult gradients from north to south of the terrain.The small party trekked even further during their 17 days, through unknown and even rougher area of the West Nar.In course of negotiating the awesome and yet picturesque terrain, the River Neora had to be crossed very cautiously several times at different places over the loose boulders and wooden logs used by the ~ accompanying Support-Team of High Altitude Porters (HAPS).The track was very narrow, meandering and branching, so that the way was easily lost.To avoid this, every precaution was adopted by the Advance Party to mark the foot-track with pieces of red cloth as signals being visibly tied to the twigs at regular intervals along the track from one camp to another in a routine manner.
Attempts of collecting specimens for about a couple of weeks were made during the course of trekking as well as at the different camps and stations.After collection, the specimens were treated with suitable preservatives.The rather limited results should not frequently be taken to indicate that the diversity of Lepidoptera in the Neora Valley is in any way impoverished.
Appendix: This gives the locality-wise material data of Lepidoptera and other particulars of the terrain surveyed.Material (c/.'Systematic Account' for the sl.no. of spp./sspp.from the coded localities given hereunder) against the dagger (t)-marked dates have been collected by R. K. Ghosh & party of the Z.S.I., and the rest by the author.'tt'-marked s1.no.indicate that the specimens have been collected 'at light' • (A) Labha (alt.c 2,400 m.): 105 kms.north of New ]alpaiguri; sl.no." (23,26,(28)(29)(30)(31)33)  Records of tl~e ZoologicaZ Survey 0/11u1,;fI Amongst numerous parasitic species, the largest climber tree is Macrocarpa.At lower elevations, the forests are characterised by the large concentration of orchids, figs and aroids, while bamboo and cane form the typical undergrowth.Due to the dense growth and low penetration of sunlight, the ferns are rather poor.In contrast, species, of Lycopodium, Ogathes, etc., are plentiful.In addition, a number of timber-yielding trees and a vast acreage of tea plantations could also be observed at Mo Chowki and Samsing.

FAUNA
The 34 species and subspecies of butterflies and moths recorded here represent only a small fraction of the diversity of the Lepidoptera from this tropical region.However, becuase little recent work has been done on the butterflies of the area and even less on the moths, the author considers it valuable to list all the speciesl subspecies found and their exact provenance.It appears that, although most of the elements are well-known to occur in north-eastern India, precise records for the Kalimpong sub-  The subspecies is widespread in the Indian subregion.Most authors would currently recognise small whites such as canidia as belonging to a separate subgenus, Artogeia Verity.The correct authority for canidia is Linnaeus (not 'Sparrman' nor 'Evans', as cited by Talbot, 1939).
The subspecies is widespread in the Indian subregion and also extends to southern China.
The species occurs throughout the Himalaya and also extends to Tibet.It is amongst a very few butterflies in India, that is known to cross the north of the crestline forming the semi-tropical extreme end of eastern Tibet (vide Mani, 1986).
Wing expanse: 55 mm.The subspecies occurs in the East Himalaya and Burma.Evans (1932) treated it as ssp.adara Moore, but Eliot (1969) has considered kamarupa Moore as the correct subspecies name, of which adara is a junior synonym.
16. Neptis mabendra samsinga, ssp.nov.(fig.2) D~8aription: Upperside fore wing with the streak beyond cell long and pointed, all the white markings narrow and lower postdiscal band directed to almost the midtermen.Underside hind wing with fuscous lines outlining the discal and postdiscal bands absent, being confined to a prominent fuscous line on the outside of discal band, and marginal fascia brownish throughout; both wings with ground colour deep brown.
Wing expanse: 60 mm.Eliot (1969) has fixed the identity of several subspecies of Nepti8 mahendra Moore.These are ssp.extensa Leech [from Western China: Szechwan], ssp.mahendra, Fruhstorfor [from the North-West Himalaya], ssp.ursula Eliot [from North-Western Yunnan] and also probably another anonymous one from South-eastern Tibet.The ssp. samsing(1, nov., differs from the foregone counterparts basically by the fore wing lower postdiscal band not directed to termen just below apex (cJ.sspp.extensa, ursula and the anonymous one), nor to apex (eJ.ssp.makendra).The new subspecies is otherwise very much close to the sspp.extensa and mahendra, having the fore wing upperside with all the white markings narrow and hind wing underside with marginal fascia not blotted out in M3-and Cula-areas, but differs from the former by the hind wing marginal fascia not whitish and, from the latter by the fore wing streak beyond cell not short and blunt.It differs from the ssp.ursula by the fore wing white markings narrow, hind wing marginal fascia not blotted out and both wings with ground colour not red.It also differs from the anonymous subspecies by the shape and size of fore wing markings and colouration of hind wing underside.

PHYSIOGRAPHY
The terrain of the Neora Valley and vicinity occupies an approximate area of 380 sq.kms.It extends from northern tri-junction of Sikkim, Darjiling and Bhutan Himalaya up to the southern foot-hill plain of Samsing, the inter-district border between Darjiling and Jalpaiguri of West Bengal.The altitude of this mountainous domain varies between c 350 and 3,000 m.The western boundary of the Valley, the I .. /n;/catin.lTr~J -rollt~ followed)

Fig
Fig. 1.Map of Neora Valley and environs

FLORA
The Neora Valley has several types of forest, with tropical and temperate vegetation amidst the deciduous, semi-evergreen and evergreen zones of the East Himalaya.All represent excellent natural resources of the area.Recently, however, certain belts• at lower reaches have been denuded by the human agency.Upper Montane Zone: This is represented by the temperate flora occurring between" 1,700-3,200 m.Of these, the commonest forms are M achilu8 ed•ulis and Ale imandra cathcartii up to the altitude of c 2,100 m.Next follows the high-level oakforest of Quercus pachyphyUs, Q. liniatta, Q. lamellosa, etc., up to c 2,400 m.Other broad-leaved varieties J such as, Acet• campbella, Ficus nemoralis, etc., are limited up to the further height of c 2,700 m.The only indigenous conifer of the area is T8uga dumosa.Amongst the epiphytes, the common forms are Ooelogyne ochracea, o. grandiflora, O. elegance, Bolbophylum sp., Ploene humilis, p. proecox, Oalanthis sp., etc.The commonest parasitic plant is a species of Harchur.The undergrowth is mainly formed by Girardiana heteropkylla and Rubu8 ellipticus.Lower Montane Zone: This is represented by the tropical flora occurring between c 750•1,700 m.A great majority of the trees are evergreen, of which the predominant species are Oastanopsis indica, O. tribuloides, Sckima wallickii, etc .. from c 750-1.500 m.
division (Darjiling District) of West Bengal have not been published previously.LIST OF SPECIESjSSPP.OF LEPIDOPTERA ENCOUNTERED [*, Recorded new for West Bengal; **, new for the East Himalaya] 11.Mycalesis suaveolens suaveolens W.-M. & de N.