ANOPHELES ALBIMANUS 983 



larly alternating long and short, the longest of the short ones less than half as 

 long as the longest of the long ones. Anal segment about as long as wide, with 

 a small dorsal plate; dorsal bnish a long and a shorter tuft on each side; a 

 single long lateral hair below the plate; ventral brush well developed, of long 

 branched tufts; anal gills moderate, about as long as the segment, blunt 

 pointed. 



The species is in many localities within its range the most abundant Anoph- 

 eles. The female is very bloodthirsty and is the most efficient host of the 

 malarial parasites. On this account the species is of the greatest economic im- 

 portance. The females enter houses in much larger numbers than the other 

 species, even though some of the latter may be equally abundant in the locality. 

 Its presence, or abundance, depends upon local conditions, chief of which are 

 breeding facilities and the blood supply. It would seem that the species does 

 not occur in uninhabited regions. 



The breeding-places are usually ground-pools of a more or less transient 

 character that may be altogether free from algae. The larvae appear to thrive 

 best in brackish water. The species has been found breeding in enormous num- 

 bers in brackish swamps of a temporary character on the Isthmus of Panama. 

 On one occasion Mr. Jennings found the larvae in pools formed by the washing 

 over of a very high tide, and which, therefore, must have been pure sea-water. 

 Analysis of water from brackish swamps in which Mr. Jennings found Anoph- 

 eles albimaniis breeding abundantly showed .92^ and 1.93;^ of sodium chloride. 



Mr. Knab found a larva in a newly-dug ditch along a railroad; Mr. Busck 

 in a puddle in the woods frequented by swine and in a stagnant ill-smelling pool 

 caused by dumping operations; Mr. Jennings got them in a rapidly running 

 river, in swamps both of fresh and brackish water, puddles in a field, ditches 

 and puddles in the Panama canal-cut, and in hoof prints. Mr. Busck found the 

 larvae associated with Anopheles pseudopunctipennis, Culex coronator, Culex 

 leprincei, and Culex interrogator. 



We quote the following from Mr. Jennings, based upon his experinece in the 

 Panama region : 



" The breeding places of this species show great diversity of character, though 

 preference is shown by the mosquito for stagnant, fairly pure water, exposed to 

 direct sunlight, with a growth of Spirogyra, which alga is a favorite food. 

 Sewage contamination is inimical to the species when such contamination is 

 marked. Eapidly flowing water also is unsuitable and streams with strong 

 current are usually quite free, except in back waters and hollows where the cur- 

 rent is little felt. I have never taken alhimanus in artificial containers except in 

 one or two instances when the occurrence was evidently purely accidental. 

 With the exception of foul or swift water they may occur in almost any collec- 

 tion of water, however small or seemingly unsuited to mosquito propagation. 

 Hoof-prints, wheel-ruts, the smallest puddle or thinnest film of water seeping 

 upon the ground from a wet hillside, particularly if the ubiquitous algae are 

 present, are points of danger and must be included in control work. For an 

 Anopheles the flight of alUmanus is strong. . . . While not domestic in the 

 same sense as Stegomyia calopus. Anopheles alhimanus is closely associated with 

 man and finds its most congenial surroundings about his habitations and in the 

 conditions he creates in the course of agricultural, engineering and other work. 

 This fact is correlated with the highly developed blood-sucking habit." 



Agramonte states that in Cuba the fertilized females pass the winter in a state 

 of lethargy in considerable numbers, hiding in stables and other buildings. 



Continental America from Mexico to Ecuador and the Greater Antilles; 

 southern Florida. 



Manzanillo, Mexico (A. Duges) ; Palizada, Mexico (A. Duges) ; San Bias, 

 Mexico (A. Duges) ; Santa Lucrecia, Mexico, October, 1911 (F. W. Urich) ; 

 Tampico, Mexico, September 3, 1903 (J. Goldberger), December 5, 1909 (F. C. 



