June, '17] HERMS: CALIFORNIA MOSQUITO SURVEY 363 



and K., Culiseta inddens Thorn. { = Theohaldia incidens Thorn.), 

 Culiseta inornatus Will. { = Culiseta consohrina Desv.), Culiseta mac- 

 crodcenoe D. and K., Uranotcenia anhydor Dyar (from larva only at San 

 Diego by Dyar). Three other species are doubtful for California, 

 PsoropJiora ciliata Fabr., jEdes calopus ]\Ieig and Culex pipiens L. 



Malaria in California 



The extent and prevalence of malaria in California is best described 

 by Snow^ viz.: "The United States mortality reports show that in 

 1909 California had one eleventh of all the deaths from malaria in the 

 registration area, which includes eighteen states, and ranked second 

 in number of deaths for a single state. Indiana was first with 125 

 deaths. New York third (95 deaths), Ohio fourth (75 deaths), Penn- 

 sylvania fifth (50 deaths). In proportion to population California 

 outranks all other states in this area. Within the state 66 per cent of 

 the deaths occurred in ten counties extending in an almost unbroken 

 chain along the base of the Sierra Nevada Mountains. The total 

 population for these counties (1910 census) is 326,896. Malaria, 

 therefore, causes five times as many deaths per 100,000 of population 

 as the average for the United States registration area. In these ten 

 counties (Shasta, Tehama, Butte, Yuba, Placer, Sacramento, Amador, 

 San Joaquin, Fresno, Kern) the 1909 death-rate from malaria was 

 one death to 4,400 people. A second group of ten counties (Trinity, 

 Sutter, Yolo, Napa, Contra Costa, Calaveras, Stanislaus, Merced, 

 Tulare, and Kings) contiguous to those of the first group shows one 

 death to each 15,820 of population. A third group of ten counties 

 (San Francisco, San Mateo, Alameda, Santa Clara, Santa Cruz, San 

 Benito, Monterey, San Luis Obispo, Santa Barbara, and Los Angeles) 

 forming a chain along the coast shows one death to each 57,614 of 

 population. Twenty-eight, or almost 50 per cent of the counties 

 show no malarial deaths. Excluding the counties of San Francisco 

 and Los Angeles, there remains the fact that two thirds of the popula- 

 tion live in counties which contributed all the deaths from malaria, 

 while one third of the population of the state live in counties which 

 had no malarial deaths in 1909. A further study of the distribution of 

 malaria in California shows Butte County 15 per cent, Sacramento 

 County 10 per cent, San Joaquin 9.8 per cent, Fresno 6.2 per cent, 

 Shasta 5.4 per cent of the deaths of 1909. Three counties, with only 

 one sixteenth of the total population of the state, have more than one 

 third of all the deaths from malaria. 



" If the counties bordering the Sacramento and San Joaquin valleys 



^Snow, William F. Malaria. California State Board of Health Monthly Bulletin, 

 pp. 276-279 (Nov., 1910). 



