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STATE BOARD OF AGRICULTURE. 



was made. The number of larvae found was nine hundred to the 

 square foot. In larger pools one hundred were found. Later in the 

 season, when the pupae congregated before emerging, the number col- 

 lected was so large that one hesitates to give them; however, in that 

 ease they were not evenly distributed throughout the water. 



The method of making accurate counts was as follows: A square 

 frame, just a foot square and an inch deep, was made of strong galvan- 

 ized iron. On the bottom of this frame was fastened fine brass netting 

 and this was marked into squares measuring an inch to the side. A 



Fig. 2.— Malarial mosquito, from Howard, Bulletin 25, n. s., U. S. Department of Agriculture. 



handle was attached to one side and the counting net was complete. 

 It amounted to a square dip net with a flat bottom marked into inch 

 squares. In using it, the net was slid into the water and left on the 

 bottom for a time until the larvae and pupae had settled into their ac- 

 customed places. The net was then raised directly upward, lifting out 

 all of the wigglers, A count of representative squares or, in case the 

 number was small, a count of the entire surface quickly gave the whole 

 number. 



In searching for the wngglers. it is convenient to have a dip net of 

 fine wire screening covered inside with Swiss muslin to render it white. 

 The larvae are most easily seen against a white groimd. When the 

 wigglers are present in numbers, the water will often look as if a fine 

 rain were falling. This is caused by the larvae and pupae as they come . 

 to the surface to breathe. This dimpling often helps to reveal the 

 whereabouts of the mosquitoes. 



