Anopheles Propagation Areas 59 



Zone land is covered with luxuriant vegetation 

 which retards evaporation. On flat lands mosquito 

 eggs were laid in shallow water pools or films of 

 water and accumulated in the relatively low spots. 

 These places were grass covered and before they 

 dried sufficiently to kill off the developing larvae, 

 another shower fell. If the wet mud was col- 

 lected and dissolved in water, mosquito larvae in 

 all stages of development were often found. In 

 excessively long rainy periods it is not easy to 

 locate, reach, and treat small places dispersed 

 over large areas', but if they are neglected, enor- 

 mous numbers of mosquitoes ensue. Evapo- 

 ration and ground absorption may or may not 

 dry ground sufficiently to prevent the develop- 

 ment of the greater part of the mosquito crop. 

 Just what will occur cannot be foreseen, nor can 

 it be estimated in advance during which month 

 of the rainy season such ideal mosquito conditions 

 may prevail. 



A variation of rainfall at villages three miles 

 apart often resulted in a large influx of adults 

 in one village and not in the other. At times the 

 areas apparently needing attention were so exten- 

 sive that the situation appeared hopeless, but 

 experience gained in each locality by the inspector 

 in charge was of great value. A new man requires 



