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THE ANIMAL PARASITES OF MAX 



Stegomyia fasciata, Fabricius (Yellow Fever Mosquito). 



This insect, which is the proven carrier of yellow fever, is commonly called the 

 tiger, brindled, spotted day or striped mosquito. It is also referred to by some 

 writers as S. calopus, Meigen. It is subject to considerable variation in colour, 

 but the thoracic markings are generally very constant. The general colour is 

 almost black to deep brown, the head with a median white area, white at the sides 

 and in front around the eyes ; the thorax has two median parallel yellow Iines 5 

 a broad curved silvery one on each side and white spots at the sides ; the scales on 

 the intervening spaces of the thorax are brown. The dark abdomen has basal white 

 bands and basal white lateral spots. The dark legs have basal white bands, the 

 last segment of the hind legs being all white except in a variety from South America 

 and the West Indies (luciensis), which has the tip of the last hind tarsal dark. The 

 abdomen may also vary in colour, some having pale scales over most of the surface 

 (queenslandensis). 



The food of the adult female consists mainly of man's blood, but she will also 

 feed on dogs and other animals. The male has been said to bite, but such is very 

 unusual. This mosquito bites mainly in the daytime up till about 5 p.m. 



The adults breed the first day after emergence. They may live a consider- 

 able time, Bancroft having kept females for two months in confinement. The 

 ova are laid separately, often in chains; they are black, oval, with a reticulated 

 membrane outside, some of the reticulated cells containing air. They may hatch 

 in from six to twenty hours, the larval stage nine days, the pupal stage three ; thus 

 the whole cycle may be completed in from twelve to thirteen days. The ova when 

 dry can remain undeveloped for a considerable time. The larvae are greyish-white, 

 with short, thick siphon, and feed at the bottom of the water, only coming to 

 the surface now and again to breathe. This is almost entirely a domesticated 

 gnat, seldom being found far from man's habitations. Its larvns occur in such 

 small collections of water as old sardine tins, jam-pots, calabashes, puddles, barrels, 

 wells in fact, wherever water is held up, even to the gutters of houses. Not 

 only are they found breeding on land, but also on board ship, although they 

 prefer artificial collections of water. They may also breed in larger natural 

 collections. 



This insect is easily transported by steam and sailing ships and by train, and 

 this doubtless explains its very wide distribution. The adults may live for fifty 

 days, and it is on this account and their frequent occurrence on ships that danger 

 lies in regard to the Panama Canal. An infected insect may leave that endemic 

 centre of yellow fever and live until the vessel arrived at the Philippine Islands and 

 fly ashore, and so introduce the disease for the native jfoftftz/a possibly to spread. 



Roughly the distribution of this pest is as follows : Africa from South to North, 

 but especially along the coast and up the Nile. In Asia, in India, Ceylon, Burma, 

 Siam, along the ports of the Malay Peninsula, in French Cochin China, Philippine 

 Islands, the Andaman and Nicobar Islands, Japan, Malay Archipelago, and East 

 Indies, Turkey in Asia, Arabia and Palestine. 



In Australia it occurs in Queensland, New South Wales, Victoria and South 

 Australia. 



In Europe in Italy, Spain, Portugal, Greece, in the Mediterranean Islands. 



In South America, Central America, Mexico, North America, and the West 

 Indies it is very abundant, and it also is found in the Bahama Islands, Fiji, Sandwich 

 Islands, Samoa, the Azores, Teneriffe and Santa Cruz, Pitcairn Islands and Bermuda. 

 For a full account of its distribution the reader is referred to the following : 

 "The Distribution of the Yellow Fever .Mosquito (Stegomyia fasriata, Fabricius) 

 and General Notes on its Bionomics;" "Mem. i er Congres international 



