THE MOSQUITOES OF THE SOUTHEASTERN STATES 



31 



feeding habits appear to be such that they are seldom of importance 

 as carriers. These conclusions are based on the fact that malaria 

 infection in this region has almost invariably been found associated 

 with this species. A. crucians is prevalent along the coastal plains 

 and in the lower Mississippi Valley, and since three specimens have 

 been found infected in nature (95, 101), the species cannot be en- 

 tirely eliminated from consideration. Barber and coworkers (9) 

 have given a critical review of the records on infection of southern 

 species and their role in malaria transmission. 



Investigations several years ago in the Okefenokee swamp in south- 

 ern Georgia (96) showed that malaria was absent in an area where 

 crucians was prevalent and the only anopheline present. In Florida 

 the malaria rate is high in the northwestern part of the State, where 

 A. quadrimaculatus predominates, but low in the southern half of 



Figure 11. — Pupal breathing tubes: A, Anopheles crucians, from above and 

 side; B, Culex salinarius; C, C. quinquefasciatus. 



the State, where crucians is abundant and the predominating species. 

 Such malarious foci as have been investigated in the southern part 

 have shown locally favorable conditions for quadrimaculatus breed- 

 ing. Frequently the two species are found associated in the breeding 

 places, but in general the occurrence of quadrimaculatus and the areas 

 of high malaria endemicity in northern Florida and southern Georgia 

 (21) appear to be correlated with the presence of slightly alkaline 

 surface waters, whereas crucians apparently prefers water of an acid 

 reaction as found more generally in the southern part of Florida. 



The species of Anopheles included here are divided into two sub- 

 genera, albimanus being placed in Nyssorhynchus and the others in 

 the subgenus Anopheles. 



ANOPHELES QUADRIMACULATUS Say 



(Syn., A. armulimanus V. d. W. ; the common malaria mosquito) 



The common malaria mosquito breeds chiefly in permanent fresh- 

 water pools, ponds, and swamps that contain aquatic vegetation or 



