October, '21] herms: anopheline notes 413 



Anopheles occidentalis D. & K. in California occurs most corp.monly 

 in the vSacramento and San Joaquin Valleys, practically throuj^hout the 

 fomier, and frOm within a very few miles of both the Oregon and Mexican 

 boundaries, i. e. straight through the state North and South from Siskiyou 

 to San Diego Counties. Except for the Sacramento Valley where infec- 

 tion is general and almost so for the San Joaquin this species was found to 

 occur only in more or less isolated foci in other parts of its range. It 

 was taken in great nim^.bers within a few feet of the ocean in Ventura 

 County where cool fogs generally prevail, and the temperature is conse- 

 quently uniform, to an elevation of 5,480 feet in Sierra County where 

 the stunmers are hot and the winters are cold. In general, however, the 

 SieiTa except the foothills are free from Anopheles occidentalis. The 

 locality in Sierra County undoubtedly is the result of influences from 

 the Northeast as are also the localities in Alodoc and Lassen Count- 

 ies. Ordinarily this species is abundant throughout its range. 



Anopheles punctipennis Sa>' on the other hand shows a distinct in- 

 clination to hug the Sierra foothills with sporadic foci in but ver\' few 

 other parts of the state. Only one collection of mosquitoes south of 

 Tehachapi contained this species, nam.ely a few specimens in one locality 

 in San Diego Count^^ Unlike either A. occidentalis or A. pseudopuncti- 

 pennis this species is not noticeably abundant in numbers of individuals 

 in any one locality. 



Anopheles psendopunctipennis Theobald has a Yevy wide distribution 

 in California, almost coinciding with A. occidentalis, though absent from 

 the extreme northern tier of counties. This species is also very abund- 

 ant everj-where that it occurs. 



In addition to the collection of adults, larvae were taken and notes 

 made relative to breeding habits. Field laboratories in connection with 

 mosquito abatement districts and other special laboratories as well have 

 been maintained in various parts of the state. Much data has thus been 

 accumulated, of which little has as yet been correlated. That A. 

 occidentalis breeds by preference in rather clear pools of water in which 

 vegetation is fairly abundant and open to sunshine seems to l^e the case. 

 A. punctipennis on the other hand apparently prefers quiet shady 

 pools. A. pseudopunctipennis evidently breeds by preference in clear 

 shallow pools along the edges of receding streams. All three species are 

 partial to mats of spirogyra which provide a convenient shelter against 

 natural enemies such as predaceous aquatic insects and surface feeding 

 fishes. 



During the summer of 1920, from May 12 to July 13, daily collections 

 of mosquitoes were made at Vina (Northern Sacramento Valley), one 



