EXPERIMENT STATION BULLETINS. 



257 



In fighting niosijuitoes, constant search is necessary. A pond maT 

 be free from wigglers early in the season and fairly swarm with 

 them later. The insects seem to become less critical in their choice of 

 breeding places as the season advances, no doubt due to the fact that 

 many of their breeding places dry up, and competition becomes more 

 acute. Another reason is that many of the ponds become covered with 

 a vegetable growth suitable for the protection and food of Anopheles. 



Pig-. :;. - Xori-mularial mosquito, from Howard. U. S. Dept. of Agr., Bui. 25, n. s. 



Another fact of interest in this connection is the habit of bunching 

 practiced by the pupae. Earl}^ in the season the wigglers are more or 

 less equally distributed over the surface of the water. When the 

 warm weather appears, the pupae are apt to collect in dense maspeu 

 and in sheltered places, often being overlooked for this reason. 



BREEDING PLACES. 



Many surprises were experienced in relation to the breeding places 

 of these pests. Mr. Barlow found a hollow in the body of a tree 

 cans«.'d by the breaking of a limb, twenty feet above the ground, which 

 hollow contained enough water to support a flourishing family of mos- 

 quitoes. On the other hand, several ponds which at first looked like 



