124 ENTOMOLOGICAL NEWS. [Mar., '15 



customer entering certain grocery stores. During the season 

 about 20 miles of ditches were cleaned and dug and over 30,- 

 ooo sewer catchbasins oiled. 



Pools in lots, surface drains, dumps and receptacles hold- 

 ing water, were also looked after as much as possible. The 

 sewers were found to furnish a constant supply of mosquitoes 

 from the middle of July until November and later, whereas 

 open air breeding was not observed after the end of October. 

 It was found that the temperature of some sewers, six feet 

 below the surface, was from 12 to 20 degrees higher than 

 that of the surface. 



In 1914 Councils appropriated $1400 for extermination 

 work and, as the city contains 129^/2 square miles, it is appar- 

 ent even to the layman that such a sum of money for a city 

 with a population of one and three-quarter million people is 

 insufficient. The attempt, however, shows progress, as such 

 a step was never thought of by any previous administration. 

 The extermination work is conducted by the Bureau of High- 

 ways under the guidance of an engineer. 



There is no actual house to .house inspection or any thor- 

 ough work done to maintain ditches in good order. The 

 force of men during the past season varied from two to eight 

 and the most efficient work accomplished was the oiling of 

 sewer inlets. Over 40,000 treatments were given from Sep- 

 tember until the middle of November. This kind of work, 

 which was carried on until the middle of December in 1913, 

 proved satisfactory, as the number of hibernating mosquitoes 

 was kept so low that no complaints were received until four 

 weeks after the heavy rains in May, 1914. With a sufficient 

 force of men destroying the newly-created breeding places, 

 the mosquitoes would have been reduced to a minimum. 

 Tanks and fire buckets in hotels, apartment houses and fac- 

 tories supplied the business sections with mosquitoes and 

 empty houses, with hoppers full of undisturbed water, were 

 responsible for infestations in the residential sections. 



A new method was tried by the Board of Health to dispose 

 of stagnant pools difficult to drain and too remote to fill in. 

 Dynamite was placed in the pools and a hole about 20 feet 



