MOSQUITO BIOLOGY 115 



There is a false appearance of a second brood coming immediately after 

 the first adults are on the wing ; but it seems fairly certain that all the 

 canadensis that are found until the middle of June are from hibernat- 

 ing eggs. After that time the species decreases in number, though it has 

 been taken in all stages throughout the summer. What seems to be the 

 second brood begins to hatch during the early days of June, and there- 

 after I have not been able to identify any definite period when young 

 were present in large numbers. 



[This is the first real pest mosquito to appear in important numbers 

 in the spring. It may be found from March or April through September 

 in all parts of the state.] 



The egg is black, spindle-shaped, smooth, rather thicker than that of 

 soUicitans. When the top has been lifted off to admit the egress of the 

 larva, it looks like a stubby, half smoked cigar. This egg may be laid 

 either on the water, through which it sinks to the bottom at the edge 

 of a pool, or on the moist ground of depressed spots. 



Breeding places are any sort of woodland pools or even larger water 

 bodies. Larvae are found in the water covering cranberry bogs during 

 the winter, sometimes in very large numbers. These bogs are covered 

 with water late in fall and are kept covered until the middle of May 

 thereafter, just long enough to mature canadensis. From that time 

 until late October the bogs are dry, and when they are flooded cana- 

 densis adults have disappeared. The eggs must, therefore, have been 

 laid on the bogs when they were dry, to account for the swarms of 

 larvae found in early May. It should be noted that these bogs were 

 closely surrounded by woodland. 



I have never found the larva in open swamps or in pools far from 

 the edge of a wood, but it was present once in a pool with cantator at 

 the edge of Shrewsbury Meadow. 



Our records show collections made in most of the counties of the 

 state, and there is probably not a bit of moist woodland anywhere in 

 it in which A. canadensis may not be found in early spring. 



Though the larvae may be found in all sorts of pools, they are com- 

 monly of clean water. Woodland springs nearly always have some of 

 them, and the pools in which they are most plentiful are those formed 

 by melted snows and early spring rains over a bed of dead leaves in a 

 depression or choked stream bed near the edge of the woodland, or in 

 a small clearing. I have never found them in really foul water. 



As nearly as can be made out from field observations, all canadensis 

 eggs that hibernate hatch between February 1 and May 10, at the 

 latter of which period adults of the earlier hatching are already out in 



