i So Mosquitoes 



make a meal two days after emerging and before 

 mating, which latter act it readily performs in cap- 

 tivity. It mates but once. The adults were found 

 from April to November 17, the length of life being 

 about that of P. hoivardii, as is the larval stage. The 

 pupal stage lasts from forty-nine to fifty-four hours, 

 in a temperature of about 60 ° F. 



Ochlerotatus bimaculatus. — Rarely found was 

 this southern species. It bred in the pool under 

 the willows on the campus, the imagos emerging in 

 October; larvae were found in the pool. The pupal 

 stage lasted from one to three days. Judging from 

 the eggs, they must winter in that form. 



The other mosquitoes breeding in the open, to 

 which I refer under this group, were not experi- 

 mented with at Baton Rouge. 



Ochlerotatus atropalpus and varipalpus. — 

 O. atropalpus, the rock-pool mosquito, is reported 

 from Maine, New Hampshire, and the Potomac River^ 

 at which last place it is very common. The adults 

 frequently make the life of the canoeist and camper 

 unhappy, while the larvae swarm in the pot-holes in 

 the rocks when the river is low. They are not only 

 in the boulders in the river bed, but also in any hol- 

 lowed stone holding rain water on the flats along 

 the river, where this species is associated with gnat 

 larvae and territans, but they are never found in 

 ground pools. They nibble over the leaves at the 

 bottoms of the cavities, seldom rising to the top. 

 They do not seem to breed in foul or even in muddy 

 water. The eggs are single, with distinct sculpture ; 

 this is evidently the hibernating stage, I have found 



