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THE MOSOUITOS OF SOME PORTS OF CHINA AND JAPAN. 



By W. A. Lamborx, 



Malaria Bureau, Federated Malay States. 



A mosquito survey, having as its object an enquiry into the distribution and 

 prevalence in certain Far Eastern Ports of Stegomyia fasciata, the known carrier 

 of yellow fever, was begun, on behalf of the Imperial Bureau of Entomology, by 

 Dr. A. T. Stanton, w^hose report was published in the Bulletin of Entomological 

 Research (Vol. x, pt. 3). As it seemed unlikely that he would be at leisure to 

 complete the observations by a survey of the ports of China and Japan, as had been 

 planned, the writer was instructed, in April 1921 , by the Government of the Federated 

 Malay States, at the suggestion of the Imperial Bureau, to complete the enquiry. 



The following ports were accordingly visited with this object between April and 

 June : Fuchow, Shanghai, Nagasaki, Kobe and Yokohama. The object of the 

 present report is to afford an account of the investigation and of the observations 

 made. 



In a latitude so far north as that in which the enquiry was commenced, nameh' 

 26"^ 8' 4", it was hardly to be anticipated that a considerable variety of mosquitos 

 would occur ; nor at the season, early spring, were great numbers of images to be 

 expected. So difficult indeed was it to discover any at all, that it was found necessary 

 to abandon the attempt to determine the presence of mosquitos by capture and to 

 concentrate on the investigation of possible breeding places, a method the surer 

 on account of recent experience, especially in the Malay States, of the breeding 

 habits of the common Culicidae. By breeding, long series of adults were obtained, 

 for it was found that the larvae of all species were little affected by the shaking they 

 were subjected to in the course of travel, whether by land or sea. Thus the larvae 

 obtained in Fuchow, China, afforded images fifteen days later in Nagasaki, in Japan ; 

 imagos were obtained in Yokohama from larvae taken fourteen da}''s previoush' 

 in Nagasaki, 853 miles to the south by rail ; and imagos emerged on the steamer 

 in Mid-Pacific, some 2,000 miles from land, from larvae taken eight da\'s previously 

 at Yokohama. 



Fuchow. 



Fuchow, the capital of the Fukien Province of China, is situated in latitude 26° 8' 4" 

 North and longitude 119'^ 37' 7" East on the north side of the Min river at about 

 35 miles from its mouth. It is 140 miles north of Amoy and 280 south of Hangchow. 



The Foreign Settlement is on Nantai, a small island formed bj^ the parting and 

 rejoining of the river and connected with the town on the mainland by an old stone 

 bridge. The Chinese town itself, with a population estimated at 600,000, consists 

 of a labyrinth of native buildings, largely one-storied, intersected in every direction 

 by lanes, usualh^ paved, and so narrow as to allow only foot traffic. 



Except for a small hill partly occupied by the Foreign Settlement, which is hemmed 

 in on all sides by the native quarters, the district is entirely flat and so little above 

 water-level that with sudden rises of the rive]-, which take place once or twice 

 aniiually, the whole town becomes inundated. Rice-fields surround it on every .side. 



The river is crowded with craft of all descriptions, from large sea-going junks to 

 small two-oar and other boats trading with the interior. The town is not 

 accessible to ocean-going vessels other than junks, larger ships anchoring about 

 twelve miles down stream, at Pagoda Anchorage. 



