Reprinted from The American Journal of Tropical Medicine 

 Vol. VIII, No. 5, September, 1928 



THE BLOOD FEEDING HABITS OF ANOPHELES 



PSEUDOPUNCTIPENNIS IN NORTHERN 



ARGENTINAi 



NELSON C. DAVIS and RAYMOND C. SHANNON 



The experiments herein reported were undertaken as a part of 

 studies by the authors on anopheline mosquitoes in Northern 

 Argentina. The technique employed was that developed by Bull 

 and King (1). 



The abdomens of freshly captured and recently fed anophelines were 

 mashed and dried on filter paper. When being prepared for examina- 

 tion, each specimen was soaked for several hours in four or five drops of 

 normal saHne solution. Antisera were secured by immunizing rabbits 

 against the following animáis: horse, cow, dog, hog, chicken, cat, 

 sheep, goat, and man. The same animal was immunized against both 

 sheep and goat; henee, the series consisted of eight antisera. Precipitin 

 reactions were read in small tubes of 1.5 to 2 mm. inside diameter, each 

 specimen being tested against all antisera, except in a few instances when 

 that for sheep-goat was omitted. 



Before being used, the antisera were tried against dilutions of the 

 nine sera, ranging from 1:10 to 1:8000. At a dilution of 1:2000 all 

 were positive with homologous antisera; in higher dilutions doubtful 

 and negative reactions began to appear. It was found that sheep-goat 

 antiserum acted promptly against 1:10 dilutions of cow serum, and that 

 cow antiserum acted, although less promptly, against 1:10 dilutions of 

 both sheep and goat sera. It is thought that these cross reactions had 

 little effect on the results of the Identification of ingested bloods, because 

 very few specimens gave a reaction in both antisera. 



The 652 specimens examined were selected from a series of 

 over 1600 female anophelines captured. Ne'arly all of the 



• The studies and observations on which this report is based were conducted 

 with the support and under the auspices of the National Department of Hygiene 

 of Argentina and the International Health División of the Rockefeller Founda- 

 tion. 



443 



