86 
MALARIA 
water hyacinth. In Georgia it was found 
by Bellamy and Andrews (1938) in shallow 
ponds with heavy growths of emergent 
vegetation, the water being slightly acid in 
reaction. 
In northern New Mexico Barber and 
Forbrich (1933) found that waters wholly 
exposed to the sun and filled with aquatic 
vegetation were usually occupied exclu¬ 
sively by A. pseudopunctipennis, while 
those completely shaded and containing 
cool water at all times were occupied exclu¬ 
sively by A. maculipennis ( freeborni ). 
Between these two extremes of illumination 
the species bred together. Barber and For¬ 
brich considered daytime temperature to be 
the determining factor in this selection of 
breeding places, although A. pseudopuncti¬ 
pennis was also found in sunlit cold springs 
at high elevations. It was also noted in 
southern New Mexico that A. pseudopuncti¬ 
pennis bred in a wider range of environ¬ 
ments. Freeborn (1926) states that way- 
side sunlit pools are breeding places of A. 
pseudopunctipennis, in which it is found 
with A. maculipennis, and that breeding 
continued in such places after they had 
become too foul for the latter species. 
A. georgianus (crucians georgianus), a 
species recently discovered by Bellamy 
(1939), was described from larvae taken in 
hoof prints and pot holes in a seepage area 
at the head of a small stream in Georgia 
(King 1939). Further observations by 
Bellamy point to pastureland seepage areas 
(“helocrene springs”) with acid waters 
(pH 5.0 to 5.8) as the typical habitat. A. 
punctipennis and A. crucians were occa¬ 
sionally found in association with it in such 
places. A few of the larvae were taken in 
a swampy, sluggish stream, and once in a 
shallow pond having a pH of 6.6, in asso¬ 
ciation with A. punctipennis, A. walkeri, 
and A. crucians. 
A. at r op os breeds in water on coastal 
marshes, where it is found in pools and 
around pond margins and on open flooded 
marshes, often in very shallow water. It 
has been found in waters varying from 
brakish to full strength sea water and ap¬ 
parently prefers those having the higher 
salt concentrations. 
A. bradleyi breeds in brackish to fresh 
waters along the coast, usually in waters 
having a salts content of 1.5 per cent or 
less. It may be associated with larvae of 
A. atropos at the higher concentrations or 
with A. crucians at low concentrations. It 
occurs in pools and around pond margins 
and on flooded marshes covered by vege¬ 
tation. 
The breeding places of A. albimanus in 
the United States have not been reported, 
although the species appears to be of fairly 
common occurrence in the lower Rio 
Grande Valley in Texas, and larvae have 
been collected there. 
Larval food. Anopheline larvae feed 
chiefly while at the surface of the water, 
and their food consists of microscopic plant 
and animal matter, both living and decom¬ 
posed, which they filter from the water 
by the action of their mouth brushes. It 
has been computed by Hinman (1932) 
from data given by foreign writers that 
a volume of water at least 20 times that 
displaced by the body of a larva may be 
filtered by it during each 24-hour period. 
Studies on the food of anophelines by vari¬ 
ous workers (Metz 1919a; Boyd and Foote 
1928; Bradley 1932; Coggeshall 1926) have 
not shown that a selection of food particles 
is made, the larvae ingesting anything of 
suitable size which comes within reach. 
Barber (1927) reared larvae of A. quadri- 
maculatus and A. crucians to maturity on 
cultures of single organisms (algae, bac¬ 
teria, and protozoa), and Hinman (1932) 
found that both these species were able to 
make a significant growth on colloids in 
suspension and material in solution. It 
would therefore appear that the food avail¬ 
able in most waters, provided it is sufficient 
in quantity, is not a prime factor in influ¬ 
encing specific breeding of Anopheles in 
various places. The presence or absence of 
different kinds of organisms may, however, 
provide an index to the suitability of water 
for breeding, as has been discussed by 
Frohne (1939). 
Enemies of larvae. Anophelines are 
