THE DRAGONFLIES OF BARKUDA ISLAND. 

 By F. C. Fraser, Major, I. M.S., and C. Dover, F.E.S. 



The Odonate fauna of the island, though rich in individuals, 

 contains only about thirty species, most of which belong to the 

 Libellulinae. A strong hint is given for the reason of the prepon- 

 derance of the latter by the remarkable number of species belong- 

 ing to the modern group Trameini in which the development of 

 the wings and the art of flying has reached its greatest perfection. 

 Insects possessed of such powerful flight as these find no difficulty 

 in crossing over from the mainland, so that it seems improbable 

 that many of them breed on the island. A few, however, pass their 

 larval stages in a small pond on Barkuda in which sedges grow in 

 abundance on the sides, making it eminently suitable for breedinn 

 purposes, especially for species of such genera as Tramea, Pantala, 

 Macrodiplax and Tillarga. 



The absence of some very common plains species is noticeable. 

 For instance, there is only a single representative of the genus 

 Trithemis ; T. aurora and T. festiva not being included in the 

 collection though they must abound on the neighbouring main- 

 land. 



Only seven species of Coenagrioninae have been taken on the 

 island, one of these being an interesting Enallagma, represented 

 by a single female, which has been described as E. insula Fraser. 

 Three of these seven species, e.s. Ceriagrion coromandelianum, 

 Agriocnemis pygmaea and Pseudagrion microcephalum, breed in the 

 pond on the island, the latter also breeding in large numbers at 

 the edge of the lake. It seems, however, that the larger numbers 

 of the individuals cross over from the mainland. Pseudagrion 

 microcephalum and Ischnura senegalensis are known to indulge in 

 comparatively long flights .and during the month of September 

 vast numbers may be seen crossing the strip of sea separating 

 Bombay Island from the neighbouring island and mainland. 

 Vessels entering the Bay there are visited by numbers of these 

 insects so that it is quite possible that a number of species are 

 carried in a similar way across to Barkuda from the Ganjam Coast. 



Dr. Annandale's observations respective of individual species 

 prove that insular habits do not differ markedly from continental. 

 Thus: Lathrecista asiatica, Potamarcha obscura and Aethriamanla 

 brevipennis are found in jungle, usually perched on the ends of 

 bare and prominent twigs; Zyxomma peliolatum flies only at dusk, 

 skimming in rapid evolutions, low over the surface of the water ; 

 Brachydiplax sobrina rests on sedge at the edge of the lake ; 

 Brachythcmis contaminala regales itself on the hosts of Amphi- 



