MOSQUITO FAUNA OF PANAMA BUSCK 5I 



Aside from obtaining a more complete list of the species of mos- 

 quitoes, much additional work is needed on the biology of the species 

 now known, both from a scientific standpoint and for practical 

 reasons in connection with the fight against the mosquitoes in the 

 Canal Zone. 



The anti-mosquito work of the Sanitary Department is considered 

 of prime importance and is carried on throughout the Zone. It is 

 a gigantic undertaking, but even now shows remarkable results in 

 the constantly improving health conditions, apparent from the health 

 reports, which are more gratifying every month. 



The Canal Zone proper is about 50 miles long by ten miles wide. 

 It includes, as far as sanitation is concerned, the cities of Panama and 

 Colon. The population of the Zone is about 100,000, of which the city 

 of Panama has about 33,000, Colon 14,000, and the Zone proper 52,000. 

 In the Zone proper this population centers at the towns La Boca, 

 Ancon, Coracal, Miraflores, Pedro Miguel, Paraiso, Culebra, Empire, 

 Las Cascadas, Bas Obispo, [Nlatashin, Mamei, San Pablo, Tabernilla, 

 Frijoles, Bohio, Lion Hill, and Gatun, with several native towns and 

 camps for employees between, all of which lie along the line of the 

 Panama Railroad. Anti-mosquito work is carried on throughout 

 the area covered by these towns and settlements. The routine 

 method is to brush, drain, and oil the wdiole area of a town or camp 

 and its surroundings to a distance of not less than 200 yards from the 

 last house in the town or camp. The same rule applies to isolated 

 houses or native towns, but outside of this area no attempt is made to 

 control the mosquitoes, on the correct supposition that these normally 

 do not fly such a distance. 



In the beginning the land is cleared by the removal of all brush, 

 undergrowth, and grass ; only shade and fruit trees are left, and these 

 are thinned out to admit sunlight and free ventilation. Where pos- 

 sible, swamps and low land are filled in, the immense excavations at 

 the Culebra cut furnishing abundant material. Then the whole area 

 is drained to carry off the surface water or any constant flow from 

 springs or seepage from the hills. This drainage is extended to all 

 new work in the canal cut and to railroad work or dumps near set- 

 tlements. The drainage is ^complished by subsoil tile drains, open 

 ditches, and open concrete or stone and cement ditches. Drain tiling 

 or cement ditches are made where possible, as they require very little 

 care afterw-ards, while the open dirt-ditches must be constantly 

 cleaned and regraded to prevent "pocketing" and the consequent 

 formation of breeding pools for mosquitoes. In open dirt-ditches 

 the algae will form in two or three days after cleaning, and to pre- 

 vent this drip-cans are placed at the head of those ditches with a 



