CHAPTER IV 



THE SPECIES OF ANOPHELES ON THE ISTHMUS 



A T the beginning of the Isthmian anti-malaria 

 •** campaign available knowledge on this sub- 

 ject was very limited, and confined largely to the 

 experience gained in Cuba. It was not known how 

 many different species of Anopheles existed, nor 

 was it definitely known which of them were the 

 important malaria carriers. The preliminary in- 

 vestigations demonstrated that they were not of 

 domestic habits similar to the Aedes calopus and 

 could not be considered house mosquitoes. Nu-' 

 merous containers near dwellings were carefully 

 examined for Anopheles larvae but none were dis- 

 covered. The propagation areas appeared to be 

 limited to seepage outcrops, pools, ponds, lagoons, 

 ditches, streams, and the edges of rivers. 



It was not thought that the daily flight range 

 was extensive, nor was any information available 

 on this subject with respect to the different species. 

 It was easy to see that rank vegetation served as a 



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