48 The Control of Mosquitoes 



distance to reach occupied houses; but is seldom 

 found in vacant buildings. 



The Anopheles pseudopundipennis is found 

 throughout the Isthmus, is not as strong a trav- 

 eler as the other carriers, and is not so commonly 

 found in houses as Anopheles albimanus or Anoph- 

 eles tarsimaculata. Its season of abundance ap- 

 pears to be more limited. Running water that 

 is relatively clear seems to appeal to this species. 

 It does .not bite as persistently as the others, and 

 its relation to malaria on the Isthmus is not con- 

 sidered important. 



Anopheles malefactor is apparently a non-carrier 

 but a vigorous biter. At times large numbers 

 of this species are found in houses. It recently 

 became the most nurnerous species at the huts 

 along the shore of Gatun Lake, when the water ele- 

 vation reached eighty feet above sea level. Several 

 months later it became relatively scarce. 



The other species oi Anopheles are not commonly 

 found in buildings, and so far as malarial fever 

 transmission is concerned are not of economic 

 importance. Regarding the identification of lar- 

 vae, Dr. Darling has supplied the following data: 



I have made no attempt to determine in detail all 

 the anatomical characteristics of anopheline larvae 

 of this region; that has been done for some species by 



