TRANSMISSION OP MALARIA BT ANOPHELES IN NORTH AMERICA 
123 
5 per 100 leukocytes. In view of Darling’s 
other negative results with A. puncti- 
macula, this observation is not considered 
significant. 
b. Infection in nature. Bennaroch 
(1928), in Venezuela, reported the dissec¬ 
tion of 58 specimens, with negative results. 
One of 6 specimens of A. punctimacula 
caught November, 1935, in the sleeping 
quarters of two soldiers at an outpost of the 
Fort Sherman reservation in Panama was 
found to contain oocysts filled with sporo¬ 
zoites (Simmons 1936a). Previously ma¬ 
laria had occurred in former occupants of 
this house and of a nearby hut. At the time 
of this observation, 101 A. albimanus caught 
in dwellings in the same area were exam¬ 
ined with negative results. Rozeboom 
(1938a) during his studies in Panama re¬ 
ferred to above, dissected the anophelines 
caught in houses with the following results : 
A. albimanus, dissected 472 and 4, or 1.1 per 
cent, were infected; A. punctimacula, dis¬ 
sected 103 and 1, or 0.97 per cent were in¬ 
fected ; A. bachmanni, dissected 3 from 
houses and 320 from pig stys and none was 
infected. Kumm and Ruiz (1939a), in Costa 
Rica, dissected 7 A. punctimacula, with 
negative results, and 559 A. albimanus, 
with one specimen infected. 
c. Epidemiological. Prior to 1910, when 
Darling published the results of his nega¬ 
tive infection experiments, A. malefactor 
(punctimacula ), was suspected as an im¬ 
portant vector of malaria in Panama, be¬ 
cause of its great prevalence in certain 
seasons and locations, and because of its 
habit of invading dwellings and feeding 
avidly on man. A. punctimacula is still a 
common mosquito in unsanitated regions in 
Panama, and its feeding habits still sug¬ 
gest that it may be an important factor in 
the transmission of malaria to troops and 
others exposed in such regions. It has been 
found naturally infected and its suscepti¬ 
bility to experimental infection is high. 
The evidence supports the conclusion that 
A. punctimacula is an efficient vector of 
malaria at least in unsanitated regions in 
Panama. Additional studies should be 
made to determine its relative importance 
there and in other countries where it is 
indigenous. 
11 . Anopheles (Cycloleppteron) grab- 
hami Theobald 1901 
a. Experimental infection. In Jamaica, 
Boyd and Aris (1929) reported negative 
experimental results with 4 A. grabhami. 
P. falciparum. Earle (1936a), in Puerto 
Rico, using wild mosquitoes, infected 8 , or 
20.5 per cent of 39 A. grabhami fed on car¬ 
riers of P. falciparum. There were 76 A. 
albimanus controls of which 14, or 18.4 per 
cent, were infected. For P. vivax and P. 
malariae there are no data. 
b. Infection in nature. Green (1921, 
1922), in Puerto Rico, during 1921 dis¬ 
sected 402 A. grabhami caught under 
houses and found 3 infected, one with 4 
oocysts and 2 with one oocyst each. In 
1922 he dissected 351 A. grabhami and 
found two positive stomachs, one with 10 
oocysts and the number not stated in the 
other. The rate of infection was about the 
same in 459 and 790 A. albimanus dissected 
in the same periods (Earle 1936a). In Ja¬ 
maica, Carley (1931) examined 125 A. 
grabhami caught in nature and found one 
infected specimen with a mature oocyst but 
no gland infection. Among 717 A. albi¬ 
manus dissected at the same time, he found 
one with a stomach infection and one with 
infected glands. 
c. Epidemiological. According to Earle 
(1936a), the low density of this species in 
Puerto Rico and its indifference to human 
blood suggest that it is not an important 
vector there. 
A. grabhami has been infected experi¬ 
mentally with P. falciparum and has been 
found infected in nature. Additional 
studies will be required to determine its 
relative importance as a vector of malaria. 
12 . Anopheles (Cycloleppteron) vestiti- 
pennis Dyar and Knab 1906 
a. Experimental inf ection. Covell (1927) 
stated that Johnson (1926) attempted, 
without success, to infect this species with 
malarial parasites in Puerto Rico. He does 
not say which form was used in these ex¬ 
periments. 
