CONSPECTUS OF ODONATA FAUNA OF CALCUTTA, INDIA

The city of Calcutta was established by Job Charnock of British East India Company on August 24, 1690. The city is known by several names-City of Palaces, City of Jay, City of Museums, City of Nobel laureates of India. It remained the capital 01 British of India up to 1911. This is one of the highly urbanised area of the country with fourteen hundred kilometer metal roads; metro rails; aquatic transport system as well as modern sky scrappers. The municipal area bas increased from 14600 acres in 1859 to 44,240 acres in 1989. The population, according to 1981 census was 9,194,018 and now it is estimated not less than ten millions excluding the regular commuters from other districts ·of West Bengal. The city has more than two hundred parks and tanks; the Maidan lies oli the Western fringe of the city. PoUution in the air and water varies from locality to locality, since there are factories for the manufacture of acids and other chemicals, plastic sheets and other articles, tanneries, Bitumen etc. in different parts of the city including its fringes.

IflDlal. Its eastern fringe is guarded by the newly established township Bidhan Nagar, erstwhile a marshy swamp known as Salt Lake, the west is bounded by the river Hooghly. METEOROLOGY The climate is monsoon type. It receives an average annual rainfall about 1580 mm and the temperature varies from the average 22.1 0 C. minimum to the maximum 31-8 0 C.

Rains:
The hot wet season is spread over the period from June to November. The north-east monsoon blows from the land, hence it brings little rains in the city. The early rains in dry hot season due to norwester or kalbaisakhi is also experienc~ in the city. In the early hot weather too, there is the season of cyclonic sto~s and tropical cyclones in the Bay of Bengal. These bring considerable amount of rainfall and often cause havoc. The south-west monsoon bursts over Calcutta in June .and heavy rainfall is experienced in the season.

SPECIES RECORDED
The present paper does not include the data on collections of species, since tho present report includes collections deposited in the National Zoological CollectioliS at Zoological Survey of India, Calcutta, and informations available from the published worlll. The area under consideration includes Calcutta Municipal Corporation jurisdiction.
The city supports fiftyeight species of Odonata spread over thirty six genera, seven families and two suborders. The taxa have been arranged according to Fraser's (1957).

Records of the Zoological Survey of India Ceriagrion coromandelianum (Fabricius)
Ceriagrion Coromandelianum, Fraser, 1933, Fauna of Brit. India, Odon. 1 : 31S-316 Laidla\v (1916 recorded the species from the city. It is one of the commonest dragonflies of India. The species is visible on the roads, ponds, drains; breeds during June to November.

Ceriagrion olivaceum Laidlaw
Ceriagrion lJlivaceum, Fraser, 1933, Fauna Brit. India, Odon. 1 : 324-325 Locally very common in many parts of India (Fraser 1933). In Calcutta it is not as common as C. coromandelianum. It is visible on the grass patches bordering the aquatic regime and floating vegetation.

lsehnura elegans (Van der Linden)
Isehnura elegans, Fraser, 1933, Fauna Brit. India, Odon. 1 : 351-354 It was first reported from Calcutta as well as from the Oriental region by Lahiri and Mitra (1976). It is a rare species.

P,eudagriQn rubriceps rubriceps Selys
Pseudagrion rubriceps, Fraser, 1933, Fauna of Brit. India, Odon. t : 296-299 It is a very common species. It breeds during June to November and sometimes form tandem pairs with F. microcephalum.

Copera lnarginipes Rambur
Copera marginipes, Fraser, 1933, Fauna Brit. India,Odon. 192-197. A male specimen was captured in a house in 1985. This is the first report of the speceis from Calcutta.

G,naca"t ha bayadera Selys
Gynacontha bayadera, Fraser, 1936, Fauna Brit. India,Odon. 3! 103-104 The present report is the first record of the species from Calcutta. Only a female specimen was collected in the night near electric lamp.

Brachythemls contaminata (Fabricius)
BrachJ'themis Contaminata, Fraser, 1936 House gecko is one of its common enemy. It breeds during the rainy season.

Mtlcrodiplax cora (Brauer)
MacrDdiplax cora, Fraser, 1936, Fauna Brit. India, Odon. 3: 448·450 One example of each sex was captured in 1967. After that no example has yet been captured from the city. It is oft,en visible in the suburban areas. It is a migratory species.

DISCUSSION
The city supports fiftyeight species and subspecies. Among them Agriocnemls nail" (Laidlaw), A. pieris Laidlaw, Cere ion malayanum Selys, Enallagma parvum Selys, Ischnurll eiegans (V. d. Linden), 1. forcipata Mortan, Pseudagrion malabaricum Fraser, Anaciaeschna jaspedia (Burmeister) Anax guttatus (Burmeister), A. imperator Leach, Orthetrum glaucllm (Brauer) and Macrodiplax cora. (Brauer) are rare species in the city. It is presumed that those species reached the town accidently either being borne by the air currents or due to their migratory habit, since none of them could be collected after the first report of their occurrence in the city.
The present paper reports fiftyeight species of Odonata spread over thirtysix genera and. seven families viz. Coenagrionidae, Lestidae, Platycnemididae, Aeshnidae, Gomphidae, Libellulidae and MacrodipJactidae recorded during the last one hundred years from the city of Calcutta.