INSECT FAUNA AND THEIR CONSERVATION IN TROPICAL NEPAL ネパールの熱帯地域の昆虫相とその保護管理に関する調査研究

Authors著者名

Keshab Shrestha¹⁾, Bhaiya Khanal¹⁾, Pusp K. Shrestha¹⁾

Summary要約

Tropical region is much disturbed part in Nepal mostly due to over population pressure and rapid deforestation. Though Nepal is regarded rich in floral and faunal wealth, study of such resources is much neglected in outer himalaya region. Thus a study was designed to explore the insect fauna and their relation to forest habitat in outer foothill of Koshi in the east, Parsa in the center and Kailali in the west of Nepal. The study comprises following five objectives (i) to make survey of insect in Koshi, Parsa and Karnali (Kailali) regions of Nepal with their status in nature, (ii) to survey plants associated with insects of Koshi, Parsa and Karnali regions of Nepal (iii) to prepare maps of survey areas (iv) to emphasize importance areas for conservation and management, and (v) to recommend proper conservation measures A total of 102, 116, 124 species of butterflies and 71, 93 and 91 species of other insects were reported from Koshi, Parsa and Kailali areas. A total of 538 species of plants, of which three new to Nepal, are reported from the studied areas. Five new reports of insects containing one hemiptera and four coleoptera were collected from Kamali region.

Lebadea martha, a nympalid butterfiy was collected for the first time from central Nepal in Parsa as its former report comes only from eastern Nepal. Concerning the management and conservation aspects, Koshi Tappu Wildlife Reserve of Koshi needs special attention to bring firmness in the conservation efforts. Artificial water sources need to be constructed in different potential sites of Parsa Wildlife Reserve. This helps to accommodate many water loving insects and butterflies. Forests along the belt of Karnali river and its tributaries need protection. Stlict rules and regulation or the development of community forest have been felt in this region. This helps to shelter rich diversity of insects and butterflies.

INDEX

• Background
• Studied Areas:
• Methedology:
• Result and discussions
• Acknowledgement
• Reference

Background

Tropical parts of Nepal is the most populated region in Nepal. Migration of people from hiil and India is uncontrolled. Most forest areas are under pressure and cleaned to make shelter for them. Forests are randomly utilized for timber, fuel, fodder, medicine etc. Due to these the good habitat for insect is declining and a point may arise when insect population will be decrease and extinct before their recording. Less attention has been paid to enumerate insect fauna and their food plants in Nepal and outer foothill is not exception. It is seriously felt that a detail study on insect fauna of the tropical region has been carried out. Vegetation is the essential aspect of insect for their existence in nature.

In the present study three region has bcen selected as representative areas. Two areas on Koshi (Map.1) and one Karnali (Map.3) has the biggest river systems in Nepal. Parsa (Map.2) in the central Nepal has also Rapti river. Thus these rivers arising from the Himalaya has much impact in the composition of flora and fauna in these regions of Nepal.

Koshi area lies in east Nepal under the eastern development region of Koshi zone. Arun and Barun originating from northem side merge out with five other rivers to make the united river called Koshi river. This belt is densely forested providing preferable habitats for many flora and fauna including the plentiful of insects. The southen part of Koshi region continue to the fiat land of Indian territory. The northern part continue to the mountainous and Himalayan regions across the other district of Himalayan border in the northern Nepal. The eastern part goes into Mechi zone, which is border line to the west Bengal of India. Koshi region encompasses five political districts of which Sankhuwasabha district makes borderline to China. Sunsari and Morang are the other districts of Koshi. Koshi Tappu Wildlife Reserve is the well known protected wetland area of Nepal lying in Sunsari district bordering Morang on the south, Jhapa in the east, Mahotari and Bhojpur on the west and Dhankuta in the north. Insect doiversity is very rich in this part. Most of the flora and fauna existing in this reserve are of the kinds preferring wetland habitat. Our study in Koshi focused along the belt of Koshi river including rivulets merging to Koshi finally and comprises tropical and subtropical climate.

The forest in this region are (i) evergreen tropical and (ii) mixed deciduous types. The former types includes forest around riverbelt and in bhawar areas. Main forest components are Dalbergia sissou, Acacia catechu, Bombax ceiba, Adina cordlfolia and Albizia chinensis, Trewia nudiflora, Mallotus phihppenesis, Syzigium cumini etc. Koshi Tappu Wildlife Reserve has three biological habitat which includes grassland 80.0%, wetland 12.9% and forest 6.3%. Commonly observed grassland vegetation along the river bank of this reserve included Saccharaum-Phragmites type. The other type includes Saccharum, Typha, Imperata and Cymbopogan. The common plant species are Lantana camera, Eupatorium odorata, Ipomoea conea, Zizyphus mauritiana and Clerodendron viscosum. The wetland plant dominant in this part are Chara sp., Hydrilla sp., Verticillata sp., Eichhornia crassipes, Nymphaea nouchali, Nelumbo nuclfera and Typha elephantine.

In the central Nepal, this study was carried out in Parsa region which is 200km south of Kathmandu. Most of the area of Parsa region is dominated by densely wooded areas showing very good diversity of various floras ranging from small herbs to big trees of different status. The warm climatic condition and varied flora has led to shelter plentiful species of insects ranging from very common to significant conservation point of views. Uniform altitudinal level of 300m except at Chainpur 1,500m has accommodated the insects of different habitat types including those of riverine forests, shaded areas, open areas, grasslands, dense forest etc. Rapti river crosses this region. The recent mountain formation, the churia or Siwalik range runs through the forests of this Parsa region. Southern side of this region is bordered to Birganj, the gate way to Nepal. Once the area was well known for its excellent forest conditions and the unique fauna existing here. This region consist of Churia on the north, mid bhawar area and southern alluvial flat land. Most of the part of this newly formed mountain is covered with good vegetation. Bhawar is specialized in having sand, pebbles and stones and is formed by the river courses coming out from the Siwalik moutain system. This area is not suited for agriculture. Important trees found in this part are Shorea robusta, Dalbergia sissoo, Acacia catechu etc. Below the bhawar area is the continuation of alluvial flatland which goes to the Indian border to the south. Parsa region is influenced by tropical climate. Regarding the forest condition, about 20% of the land of this part have very good forest coverage. On the basis of climatic condition, three main types of forest exist here. These are new riverine forest, old riverine forest and bhawar or Churiya forest.

New riverine forest is developed due to the deposition of fertile soil brought by river courses in different areas of this region. Warm climate and good rain has led to grow dense forest in such areas. Old riverine forest occurring in this part is little elevated from the river courses. Flood during monsoon times does not affect this forest Hardwood evergreen forest is found in this part. Shorea robusta in the dominant forest of area. In addition to this, Bombax ceiba, Albizia sp., Adina cordifolia, Terminalia alata, Dalbergia latifolia, Teminalia chebula, T. bellirica are also common. Besides the rich diversity of insects, this area is also rich in other fauna and birds. Among interesting mammals found in this part are elephant, tiger, bear, leopard, wild cat, jackle, fox, blue bull, swamp deer, spotted deer, gaur bison, porcupine, wild boar, four horned antepole and hares. Prominent reptiles of this part are king cobra, cobra, python and crocodile. Sometimes these fauna migrate to nearby district of Chitwan, which provides very good and diverse habitat for many wildanimals. Interesting birds observed here are jungal fowl, pheasants. Iongtailed magpie, drongos, swallows, serpent eagle lapwings, warblers, robin dayal, doves, wild pigeons etc. Important butterflies reported here are Athyma sp., Neptis sp., Papilio sp. Important beetles are callistus sp., Saprinus sp., Pseudoides sp., Sisyphus sp., Drepanocerus sp. and many more.

Karnali river borderes Kailali district in the west and Bardia district in the east. Karnali river has many diversification in the border side of Bardia National Park and composed many small river islands. This area offer many factors for the richness of insect diversity. In Kailali district Ghoda Ghodi lake (150m) provide varied habitats preferred by many insect species. This is an IUCN protected lake accommodating mixed forest around and is still least disturbed area. Geographically, the northern part adds its altitude and continues to many mountainous districts up to the higher elevation of Jumla district of Midwest Nepal. This brings total changes in the vegetation and the sheltering insect species and other fauna existing here depend upon such vegetation. Climatic condition is very cool in such areas. The southern part of Karnali region continie to the Great Indian plain making least differences in the elevatiorn. Summer is very hot and vegetation pattern is almost similar with the characteristics to survive in warm and humid conditions. Due to the presence of good vegetation and weather, southern belt of Karnali region represents good insect diversity as compared to the northern belt.

Royal Bardia Nationa Park encompassed by Karnali region is well protected and maintained for unique flora and fauna characteristic to subtropical climatic zones. This park covers an area of 968 sq.km, which also includes the newly formed mountain system of Siwalik or Churia ranges. Due to the presence of multifarious plant species. the insect fauna present here are numerous and interesting, and keeps significances as previous works on insects are lacking from this part. The Karnali river, which originates from the northern Himalaya and Tibet. after reaching Chicapani makes tributaries in three places viz. Sati, Rajapur and Mohana rivers of this region. Many parts of Karnali regions are still beyond our exploration due to the increasing activities of terrorist. The main concern of Karnali region is the increasing deforestation rates. Hill and mountainous peoples started to migrate to Karnali's fertile areas when Government opened its settlement program after clearing the existing luxurious forests of the is part. Besides this, many peoples migrate here, cleared up the forests for their requirements to extend their agricultural practices and to established their own business. So deforestation rate is very extensive in these areas. Royal Bardia National Park, now has made its extension keeping in view to conserve rare and endangered flora and fauna occurring here. Many unique and interesting mammals like one horned Rhinoceros, Bengal Tiger, Blackbuck, Asiatic Elephant etc are found in the forest of Karnali region. Interesting reptiles like Crocodiles, Gharial, King Cobra, and many other species exist here, This region is the paradise for bird and insect enthusiasts. Very rare mammals like river Dolphins are numerous in this part. Insect diversity shown by this study is remarkable along the belt of the riverine forest of Karnali.

Studied Areas:

1. a) In Koshi, Itahari, Koshi Tappu Wildlife Reserve, Prakashpur, Rajabash, Chakraghati, Ramdhuni, Chatara, Kusaha, Rajabas, Chhinamasta, Barahchhetra, Tribeni, Simle, Lamibagar, Piula, Lunibagar, Anderighat Pakhribaas, Dhankuta and Basantapur.
2. b) In Parsa, Adnabhar ( Parsa Wildlife Reserve ), Niumalbasti, Pattlaiya, Amlekhganj, Hetauda, Bhaise, Bhimphedi, Manahari, Chainpur, Lothar, Sunachari, Churia, Pratapur, Machan and Teen Piple, Birganj.
3. c) In Karnali, Tikapur, Khargwar, Satti, Rajapur, Kothiaghat, Mohana, Lamki, Ghoda Ghodi Lake, Chisapani, Kachali, Bhrigaon, Thakurdwara, Lalmati, Sitakund, Katachhi, Chhatiwan.

Methedology:

Above mentioned places were visited two types in a year in different seasons. Butterflies and insects were collected by sweeping the insect net. Waternet was used to collect aquatic insects. Beating and sweeping method was followed for those insects sheltered in shrubs and tree-branches. Light trap was also used to collect night insects. Insects inhabiting in dung, excretory matters were taken directly by forcep and killed them in killing bottle. Food plants of most of the insects were identified in the field. Some of the insects were identified by tallying with the specimens preserved at the Natural History Museum, T.U and Entomology Section (NARC), Kathmandu. Literatures consulted for the identifications were as follows: Anada, et al. (1978), Andrew (1935),Arrow (1917, 1925, 1931, 1939), Distant (1902, 1904,1906,1908), Fletcher (1914), Fowlwe (1912), Habu (1967), Jacoby (1908), Kapoor et al. (1978), Kirby (1914), Kimoto (1972, 1973, 1979, 1981, 1982), Kimoto and Takizawa (1981), Lynerberg (1976), Numata (1989), Shrestha (1980,1982,1999), Tetsue and Shinji (1999). For identification of plants species, seeds, flowering and vegetative parts were collected, and identified in the field and in the Natural History Museum using the literatures of Maheshwari (1966). Shrestha and Corvinus (2000) Shrestha (1984), Polunin and Stainton (1984), Stainton (1988), Butterflies were identified with the help of Smith (1989), Khanal and Smith (1997). Insects and plants are deposited in the Natural History Museum.

Result and discussions

a) Koshi region

In Koshi region a total of 173species of lnsects and 297 plants has been reported. The most common and prevalent butterflies species occurring in this part include Euploea core, Eurema hecabe, Catopsilia pyranthe and Castalius rosimon. Rare species recorded are Delias pasithoe, Ypthima kashimira, Rapala rectivitta, Leptosia nina, Naceduva kurava etc. The total species reported in this region comes to be 15% of the total species (645 species) found in Nepal. Most of the species occurring in this part belong to tropical climatic types and are said to be oriental species. In the hilly region of Koshi species such as Cethosia bibles, Libythea myrrha. Papilio menon and Loxura atymnas. Pieris brassicae, white butterflies which was not observed in Koshi Tappu Wildlife Reserve are numerous in Pakhribas and Arun river side. Axias pyrene, an oriental species was very common along the belt of Arun and Koshi river. This butterfly shows sexual dimorphism. It has two generations in a year. Common among the commonest species observed in our study is Eurema hecabe. This species was found attracted to leguminous plants occurring in wild and cultivated both. Castalius rosimon, a small lycaenid was very abundant in Koshi tappu in August, but it was very scare during Januay in the same year. This provided us a very good conclusion that the winter season checkered the growth of leguminous plants in this part which in summer had luxurious growth thus increasing the population of Castalius rosimon.

During summer time

Insect diversity was found to be high in hilly and mountainous regions as it is the transitional and meeting zones for both the oriental and Himalayan species. Most of the species observed here are the derivatives of eastern Himalayan elements. Eastern part of Koshi region, close to Dhankuta is Sankhuwasabha district and is found to be the best region for insect diversity in Nepal. About 90% of the insect species occurring here are the east himalyan species. More than 15 species of butterflies occurring here are not recorded in other parts of Nepal but are found in the east Himalayan range of Myanmar, Sikkim and Assam State of India. Endemic and endangered species of insects (except one) were not observed in Koshi region in the present study. Saprinus subcoerulus is the only endemic coleopteran insect collected at Koshi region. Beetle species, Cicindela fabrici, Lanka brunnea and Selina westermani are the rare species reported in Koshi. Likewise a beetle, Onitis castaneus was collected from the dung of Wild water buffalo. Among the other rare species of insect reported in Koshi region are the Hemipterons Antestia anchora feeding upon Eupatorium plant, Graptotethus trisignatus and Coleopteron like Dactylispa daipa, Onthophagus rectocornis, O. cervus on cattle grazing sites where dungs were deposited. also provided very good diversity of Coleopteron species. Likewise forested areas at Koshi Tappu also provided very good diversity of forest insects. From the present study it has been found that the season for insect in lower basin of Koshi region was found from March onward till the start of November. Maximum diversity was found in July/August. December to the end of February represents very low diversity due to the cold climate and poor floral growth. It is very interesting to note that even in the month of January, the forest of Charata (Sunsari, 500m) provides very good diversity of insect species. In January, 42 species of butterflies and 15 species of other insects were recorded from this area. In Chatara the richness of insect fauna is claimed due to the evergreen mixed forest and good source of water. Due to these factors butterfly diversity is rich even during the extreme cold months of the year. Warm, humid and good vegetation in this area influence the richness of the insect diversity as well. Koshi regions receive heavy rainfall in the monsoon time. This has left direct effect upon the insects occurring here. Insects here are more brighter and darker compare to the insects of west Nepal. The main butterfly season in northern mountainous parts of Koshi region starts generally from may onward till the end of October, peak time is July/August months of the year. October to June represents dry season forms with less prominent colours and spots. The only new report on insects made during our study in Koshi region is Onitis crassus and Onitic castaneus, dung beetle reported close to forested area of Chatara.

A total of 63 specics of insects (Coleoptera, Hemiptera, Hymenoptera and Dictyoptera) besides butterflies were reported. Majority of them are Coleopterons. Most of these insects were recorded from warm, humid and forested lower basin of Koshi region. Huge wet land areas of Koshi Tappu provided some water beetles as well. 66 species of insect under 67 genera 5 orders and 44 food plants were reported. Rare species of insects include Hemipterons are Fitha arden, Placosternum taurus, Antestia anchora, Belostoma indicum, Cosmocarta inclusa, Coleopterons includes Selina westermani, Dicranonus circumdatus (Carabidae), Lanka brunnea, Morphosplaera montivaga, Leptispa nigra, Aphrodium cribricolle, Lophosternus indicus, Aceraus grandis etc. Ecologically they are mostly forest species and are distributed largely on the wooded mountains and valley, south of the crestline of the Great Himalaya and to a very small extent in the east and. central Himalaya and gradually disappear at the western end of the Himalaya at the Sutlej defile.

b) Parsa region

Parsa region in the central Nepal was explored twice in a year in the month of February and September. A total of 116 butterflies categorized under 10 families were recorded. About 70% of these recorded species are oriental. Pieris brassicae, Eurema hecabe and Lampides boeticus recorded in the lowland of Parsa region also exist in higher Himalayas up to an altitude of 450m (Smith 1989). These are the cosmopolitan species occurring in all the altitudinal levels of lowland, mid hills and Himalayan region. Besides their distributional pattern, Lampides boeticus is a oligophagus species which feed on cultivated crops and forest plants as well. Rare species Neptis procris, Rapala sp., Hestina nama, Ypthima newara, Pachiliopta aristolochae and Jamides bochus are seen only in some parts of Parsa. Lebadea Martha is the first report made from Parsa region as its former report comes only from eastem Nepal (Smith 1989). Widely observed common species in this region are Catopsilia pyranthe, Zizeeria maha, Precis orithya, Melanitis leda etc. Species like Colias fieldii, Nymphalis canace and Orsotrioena medus are very common species. Colias fieldii is a paleartic species occurring up to an altitude of 3,500m, is very scare these days. This species was observed only at Teen Piple near Lothar. Colia arate is its allied species and was very common few years before. In Brindaban, 28 species of butterflies were recorded of which Precis almana, Euploea core and Ypthima sp. And Papilio demoleus were abundant and was seen attracted to the citrus plant. Kallima inochus, a dry leaf butterfly in fresh form was observed here attracted to citrus plant. Likewise, Symbrenthia sp., Catopsilia pomana, Cyrestis thyodamus and Precis atlites were also seen around citrus trees. During the month of February, Papilio polytes and Vanessa indica were quite fresh forms. The forest of this part has been opened for settlement for landless people thus destroying a vast area of mixed trees for human settlements. The dominant vegetation here are Shorea robusta, Pinus roxburghii, Schima wallichii, Bombax ceiba, Dalbergia sissoo and Acacia catechu.

Adhavar is the headquater of Parsa Wildlife reserve and is one of the potential site for insects. Different places in this reserves were visited. This reserve is very dry except Kaminidaha. So water loving and aquatic insects are almost lacking in the reserved. Shorea robusta, Terminalia alata, Semicarpus nacardium, Syzygium cumini and Aegle marmelos are the dominant species of plant of this part. Curetis bulis and Pachiliopta aristolochae are the only rare butterflies recorded in this arca. Aglais cahmirensis was the common species attracted to Urtica plant. Common species like Papilio demoleus and Melanitis leda were seen attracted to citrus and bamboo plant respectively. Besides butterflies all other insects of this part are of common status except Abulfeda punctatus (Hemiptera). Leptispa samikirna (Coleoptera) and Chalaenius hemifer (Coleoptera). Hemipterons like Lohita grandis, Iphita limbata, Physopelta bivittata and Chlaenius hemifer are the rare coleopteron insects existing in this part. Beetles like Monochilus sexmaculata, Coccinella septopunctata and Hister benghalensis are the most common species found in this part. Aglais cashmirensis, Hypolymmanas bolina and Venessa indica were seen attracted to plant like Tridax procumbens, Justicia sp. and Urtica dioca. 26 insect species under 2 orders (Hemiptera and Coleoptera) exist here. Abulfeda punctata (Hemiptera) and Physorrhynchus tuburculatus (Hemiptera) are rare bug species occurring in this part. Rare beetles like Dactylispa daipa was found feeding upon Dalbergia sissoo and Polygonum sp. Tiny dung beetle, Onthophagus rectocornis was found feeding upon cowdung and dog faeces. Most of the insect occurring in this part are dependent on agricultural crop, grasses and dungs.

Padam Pokhary and Churia (430m) are the next sited of our study program. The main vegetation of this area include Terminalia alata, Shorea robusta, Ficus semicordata, Daubanga grandiflora etc. Orchids like Vanda sp., Dendrobium sp., Pholida articulata are also common on the tree trunks. These area represent 23 butterflies species categorized under 5 families (Papilionidae, Pieridae, Nymphalidae, Lycaenidae and Danaidae) Rare species of this part are Moduza procris and Arophala sp. Most common species existing in this part are Eurema hecabe feeding upon leguminous plant, Neptis hylas, Pieris brassicae, Precis iphita, Danaus chryssipus etc. Among other insects 13 species of two orders (Hemiptera and Coleoptera) were found here. Callistus lunatus, is the only rare carabid beetle reported here. Common hemipterons existing here are Eusacocoris rosaceus and Dysdercus cingulatus. Aquatic common bug Ptiomere laticaudata also exist here. Common beetles found here are Monolepta signata feeding upon Polygonum plant and Apiona gangeticum feeding upon Rubus ellipticus plant. Likewise Clerodendron viscosum and Mazus rugosa are the host plant of Coccinela septopunctata.

Limenitis procris, a nymphalid butterfly is the new addition made at Bhimphedi. Catopsilia pyranthe, Precis almana, Pieris brassicae and Eurema hecabe all of common status found here. Ypthima kashmira was the rare species. In February the most common species observed were Catopsilia pomana, Papilio polytes, Euploea core, Danaus genutia, Papilio demoleus, Graphius sarpedon and Cupha erymanthes. Eurema hecabe and Eurema laeta are also found of which the later is rarer than the former. These species rely on leguminous plant for their food. This area has 29 species of insects including Orthoptera, Hemiptera and Coleoptera. This area provide good habitats for Hemipterons like Erthesino fullo, Leptocoriza acuta and Lohita grandis of which the food plants are Trewia nudiflora and Mallotus philippensis. In Lalimati the most common beetle species recorded are Coccinella septopunctata, Gonocephalum civicum, Aspidomorpha sanetae-crucis and Aspidomorpha milaris. Of which the food plant of Aspidomorpha santae-crucis and Aspidomorpha milaris is lpomoea cornea. All these species were also reported from Koshi and Karnali as well. Onitis subopacus is common species reported from this part. This species occurs in all the sites of Koshi and Karnali region of our study program. Its habitat was found to be interesting in all the three places. In Koshi region it was reported from buffalo's dung while in Adhavar (Parsa) and Karnali region these were collected from wild elephant and cow's dung respectively. Pratappur is the next potential site and was revisited in September. A total of 31 species of butterflies were recorded from here. Pachiliopta aristolochae and Ypthima sp were the rare species recorded here. The most common species sighted here are Catopsilia pyranthe, Goneptery rhamni, Precis almana, P. Iemonias, P. atlites, Eurema hecabe etc. In Nirmal Basti (Parsa). A rare butterfliy Nymphalis canace was found in the Smilax plant. Other insects also showed a good diversity in September. Good growth of vegetation and warm weather also influenced to flourish. Among the common insects recorded in this season are Coccinella septopunctata, Brumus saturalis, Gonocephalus civicum, Philopona birmanica etc. These are all Coleopteron insects which also exist in Karnali and Koshi region. Chlaenius hemifor is the only rare species recorded from this part. Among the hemipterons Erthesina fullo, Leptocoriza zcuta, Lohita grandis and lphita limbata (food plant-Trewia nudiflora) are common species. Insect species showed increasing from 29 to 43 in Parsa in September than in February.

c) Karnali region

Karnali region was explored from every corner along the belt of Karnali river and its side tributaries which goes up to the Mohara river of Indian Uttar Pradesh states. This region provided varied habitats for diversified butterfly species ranging from the small lycaenids to the big papilos. During the first phase study of Karnali region in mid summer time before the monsoon revealed the existence of species of butterfly categorized under different families. Among the rare species observed there during this time includes Ypthima kashmia, Symphaedra nais, Graphium euros, Elymnias hypermnistra and Curetis bulis. This region is almost with the uniformity in altitudinal level and has forest of different types like mixed forest, deciduos forest, evergreen forest and riverine forest. Both the old and new riverine forest exist in the part. Many forested area are also run, by the local communities maintain in excellent condition. Common butterflies existing in these forest are Precis almana, Danaus chryssipus, D. genutia, Papilio demoleus, Catopsilia sp., Eurema hecabe, Gonepteryl rhamni, Pantoporia hordonia, Zizeeria maha etc. No endemic and protacted species were seen existing in this region during first phase program.

Bardia encompasses one of the largest National Park of midwest Nepal. This national Park has played a vital role to protect many valuable insect species in wild. Chispani is one of the potential site for many insect species. Situated on the bank of Karnali river, Chisapani still maintains good forested areas. Vegetation like Dalbergia sisoo, Shorea robusta, Cassia fistula and many types of grasses are dominant in this part. Butterflies like Eurema hecade and Cepora nerissa were found abundantly in this part. Good diversity of insects were observed at Lalmati area of Royal Bardia National Park. A total of 26 species of butterflies were recorded from the well managed forest of Chisapani and Lalmati areas. Next potential site for insect in Karnali region is the Sati Karnali area. Very good forest run by the locals exist here. Our study revealed the existence of 23 species of butterflies in this community forest covering an area of 139 hectors. Rare species of butterflies observed here are Ypthima kashmira and Athywa sp. One of the most potential site for our study program was found in Ghodaghodi lake of Kailai District, Midwest Nepal. This is a protected lake by IUCN and has very good forested areas around. About 15 species of butterflies were found in this part during our first phase program held in the month of May. In Lalimati forest, Iycaenid butterfly Castaliun rosimon was also observed. This species is the most common species in Koshi region. Castalius rosimon is not so common in Lalimati area like in Koshi region. Rare species of butterfly reported in Lalimati forest is Symphaedra nais, a red nymphalid and is categorized rare under the national status.

Karnali region is a vast and represent many potential sites for many insect species. Total insect species besides butterflies, reported from this region includes 69 species under 59 genera. This includes Orthoptera 5 species (5 genera), Hemiptera 2 species (2 genera) and Coleoptera 44 species (34 genera). Among the reported insects during the first phase program, Captosomus siamicum, Tesseratoma javanica, Homoeocerus signatus, Mononyx turgidulus and Otinotus oneratus were rare Hemipterons, not found in Koshi and Parsa regions. Rare Coleopteron insects reported in our first phase program are Neocollyris attenuata, Cicindela octonotata, Scapterus sulcatus, Cryptocephalus dodecastigma, Gymnopleurus gemmatus, Gymnopleurus dejeani, Onthophagus bonasus and Onthophagus pactolus. Onthophagus pactolus is confined to Bardia region and is found to be new to Nepal. Other new report includes Scarabaeus sanctus, Phalops oliivaceus, Gymnopleurus gemmatus, Onitis singhalensis (Coleoptera) and Captosoma siamicum (Hemiptera). Almost all insects collected are the forest species. Due to well protected forest conditions, this part is very rich in forest insect diversity. Riverine forest of this area also provides good habitat for many insect species. Reported insects from this site includes Cicindela octonotata, Scapterus sulcatus and Gymnopleurus gemmatus, all are Coleopterons. Belostoma indicum (Hemiptera, Giantwater bug), Orectochilus metallicus (Coleoptera), Micronecta heliploides (Hemiptera, boatmanbug) are the only insect species collected from aquatic habitats. So various habitat types were visited during the first phase program in Karnali region. Most common species of this area is Lohita grandis, Iphta limbat and Physopelta schlanbusch (Hemiptera). Physopolta schlanbuschi is the most common species, found abundantly in riverine wooded land and riverine grass land of this areas.

In November the region was still warm enough to accommodate different insect species of various status. One Euthalia species, Castalias caleta, Elymnias hypermnestra (female), Yphthima kashmira and Papilio epycides were the rare species. Among the common species common in the November month are Eurema hecaba, Precis atlites, Melanitis leda, Precis iphita, Pieris brassicae, Catopsilia pyrathe, Danaus genutia and D. chryssipus. Rajapur and Kothiaghat area were very poor for butterlies and other insects. Very poor vegetation and high human settlement exist in these area. Forest along the riverbank is almost nil, mustard and sugarcane cultivation cah be observd in some parts. In Sati Karnali a total 20 species of butterflies was reported in November which is fewer than in May. Three butterflies, namely Mycalesis perseus, Ypthima sp. And Elymnias hypermnestra are the new addition to previous collection. Plentiful of Nemeobiid butterflies, Ariadne merione were seen attracted toward castor plants. Among the most common species observed in this forest are Eurema hecabe, Castalius rosimon, Zizeeria maha and Neptis hylas. Shade loving species like Mycalesis perseus and Melanitis leda were also found in this part. 22 species with 21 genera have been reported including Coleoptera (13 genera, 14 species) and Hemiptera (8 genera and 8 species). Among the rare insects are Fitha ardens (Hemiptera), Cydnocoris crocatus (Hemiptera), Vesbius perpurens (Hemiptera) and Belostoma indicum (Hemiptera). The most common species include Lohita grandis, Physopelta schlanbuschi, Nephottettix apicalis, N. bipuactata, Coccinela septopunctata, Aspidomorpha sanctar-crucis, A. milaris and Gymnopleurus cyaneus. 44 species food plants of insects are reported from this area. The most common insect species include Acrida turitta, Chrotogonus trachypterus and Poecilocerus pictus (Orthoptera) recorded from the flooded land of Karnali river. Poecilocerus pictus was foud feeding on Calotropis gigantea along with other insects. Schleichera oleosa, Lalki Bathania (local name), Calotropis gigantean, Buddleja asiatica, Acacia catechu, Dalbergia sissoo, Trewia nudiflora, Mallotus philippensis, Perilla frutescens and Callicarpa microphylla are the important food plants of insects of this area. 16 species of dung beetles are reported from the forest of this region. Among them 4 species are new to Nepal.

Conservation of insect fauna is one of the essential task specially in the country like Nepal where impact on forest is increasing in an alarming rate. In what rate the insect rate are facing attenuating is not known but diversity of insects are decreasing and are becoming scare in the nature. In Kosh, 20 species of insects are found to be rare including one endiemic and one new to Nepal. But except Koshi Tappu all other region are loosing forest die to lack of conservation knowledge. Even Koshi Tappu area need strict conservation measures as invasion and disturbances are increasing in alarming rate This area need extension of conservation area extending to the churia range in Chatara and Patnale where butterflies and insect diversity is very rich. A total of 302 species of flora are recorded from the studied area with two species new to Nepal.

Insect diversity is comparatively higher in Parsa area than Koshi and Karnali. About 75% of the studies area fall under the protected area. Rest part facing enchroachment form the new comers in the area from the hill and the peripherial localities. A total of 116 species of butterflies and 85 species of insects of which one is found to be endemic and 20 species are rare carrying urgent conservation requirement. Sapribus subcoerulus is the endemic beetle found in Parsa. This part has loose and porous soil condition so the rainwater does not get accumulated here. This makes this place devoid of water sources which ultimately leave impact to the existence of many insect species. 305 species of plants have been recorded in the surveyed area. Construction of artificial ponds and lakes are required in the reserve. Those ponds be constructed in different areas of the forest where the habitats are good for the insects. Anti poaching patrolling should be increased and illegal cutting of the forest trees should strictly controlled here as well.

Karnali region has also shown very good diversity of insect as well. 78 species of butterflies and 81 species of insects are reported and categorized under different status. Here 25 species are under rare and 5 new species have been reported to Nepal. Study here was mostly confined to the forested areas in National Park and community forests. Ghoda Ghodi lake though protected by IUCN still need effective conservation method. Areas in Karnali has potential to attract tourists also if those protected areas are well studied and implemented strict conservation measures. The main problem concerning the conservation management in this are is the lack of boundary wall. In many place guard system is lacking as well. Other areas of our study sites do not keep so much significance for the insect diversity except in the protected areas due to the human interferences.

Acknowledgement

This study was supported by Pro Natura Fund to the first author. Our sincere thanks are due to Prof. Dr. M. Ohsawa of Chiba University and Dr. T. Nakaike of Natural History Museum and Institute, Chiba, Japan for their kind support and encouragement. Thanks are also due to Dr. T. Maskey, Director General of department of National Park and Wildlife Conservation (HMG/N), Prof. Dr. Krishna Manadhar, then dean of Institute of Science and technology, TU, Wardens of Koshi Tappu Wildlife Reserve, Parsa Wildlife Reserve and Royal Bardia National Park, Chairman of Satti Community Forest and the staffs of Natural History Museum for their cooperation during the work.

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