MOSQUITO 



396S 



MOSQUITO 



tracted the disease. The inmates of the other 

 room occupied the same beds and wore the 

 same clothing that had been used by yellow- 

 fever victims, without any use of disinfectants. 

 Although the only precaution taken was to ex- 

 clude mosquitoes both day and night, not one 

 person became ill. Thus was furnished positive 

 proof that yellow fever is not contagious, but is 

 spread by this particular mosquito. Tests have 

 shown that it takes about two weeks after the 

 mosquito is infected before it is able to convey 

 the disease, indicating that the poison or germ 

 undergoes special development in its body. 

 See YELLOW FEVER. 



There is another disease that this same mos- 

 quito is guilty of spreading, even more terrible 

 than yellow fever because always incurable, 

 although happily not so common. That is the 

 repulsive affliction known . as elephantiasis. 

 After a mosquito has bitten a victim of this 

 dreaded disease there is a period of three weeks 

 before it is capable of passing on the infection. 

 In some parts of the world the distribution of 

 the disease is due to the agency of a certain 

 species of the Culex mosquito. 



The Tiny Mosquito and the Big Panama 

 Canal. If it had not been for the destruction 

 of the mosquito as a disease-carrier, it is doubt- 

 ful whether the gigantic project of digging the 

 Panama Canal could ever have been carried 

 through. The greatest difficulty the French 

 had to contend with in their attempt at its con- 

 struction was the mysterious fever which car- 

 ried off their workmen by the thousands. 

 When the United States took over the task, 

 the first thing the authorities put their hand to 

 was sanitary work making the Canal Zone a 

 fit place in which to live. This required almost 

 two years and cost millions of dollars. It was 

 accomplished by Colonel (later Major-General) 

 W. C. Gorgas, with the cooperation of the 

 army, and its success has entitled him to equal 

 honors with the great engineers who solved the 

 purely mechanical problems. 



Having learned the art of mosquito warfare 

 during the yellow-fever fight in Cuba, Colonel 

 Gorgas knew just what was needed. He and 

 his "health squad" drove the mosquitoes out of 

 the plague-ridden cities of Panama and Colon 

 by a thorough campaign marked both by am- 

 bush and by open attack. They fumigated all 

 ships, since mosquitoes are often carried by 

 this means; they filled the drains, swamps and 

 pools with the earth dug out of the canal ; used 

 petroleum to destroy the wrigglers in breeding 

 places that could not be drained or emptied; 



installed modern sewer, garbage and water- 

 supply systems; paved the streets; fumigated 

 and screened the houses, killing all insects 

 found indoors; and kept fever patients segre- 

 gated, not necessarily from healthy people, but 

 from mosquitoes. As a result of the vigorous 

 measures enforced in the Canal Zone, the death 

 rate from malaria and yellow fever is now 

 actually lower than that of New York or Wash- 

 ington, and a mosquito is almost a curiosity. 

 This conquest of the mosquito in the tropics 

 is one of the great triumphs of the century. 

 See GORGAS; PANAMA CANAL. 



Campaign Methods and Weapons. The strong- 

 est weapon that can be used against the deadly 

 mosquito is that of prevention, using the 

 methods already discussed in connection with 

 the campaign in Panama. This gets at the 

 very root of the matter and. is the only really 

 satisfactory defense method. In addition to 

 'large-scale methods, however, it is necessary to 

 educate the individual householder out of the 

 careless habit of leaving rain-catching recepta- 

 cles about the premises or in vacant lots. If 

 the mother mosquito can find no near-by place 

 to deposit her eggs, the problem is practically 

 solved for that locality, as only a very small 

 number of mosquitoes are carried by trains, 

 boats, wagons or winds. 



Against mosquitoes already hatched the chief 

 weapon used is the oil can. If there is a thin 

 film of kerosene over the surface of the water 

 where they have hatched, the wrigglers are 

 unable to project their breathing tubes through 

 for the life-giving air, and thus drowning de- 

 stroys a whole generation. It requires only a 

 small amount of oil to film the surface two 

 tablespoonfuls (one ounce) for fifteen square 

 feet but the application needs to be repeated 

 every two or three weeks during the mosquito 

 season. This oil method, however, is only a 

 protective measure, affording temporary relief. 

 It cannot compare in effectiveness with the pre- 

 ventive method 

 of destroying the 

 breeding places 

 altogether. 



The Mosquito's 

 Natural Enemies. 

 The dragon fly 



has acquired such 



A natural enemy of the 



a solid reputation mosquito. Do not molest it, 

 as a mosquito foe for u is a beneficial insect, 

 that it has been nicknamed the "mosquito 

 hawk." One of the best helps a community can 

 have in its war on mosquitoes is a community 



DRAGON 



FLY 



