214 entomological news. [June, '06 



Notes on Mosquitoes. 



By Dr. S. E. Weber, Lancaster, Pa. 



(Plate X) 



Culex pipiens Linnaeus. 



This domestic species which loves human habitations, and is 

 found throughout the greater portion of the civilized world, is 

 the commonest mosquito about Lancaster and other localities 

 in Pennsylvania. It is still looked upon as breeding in rain 

 barrels or any other receptacle containing fresh water, but I 

 have long known this species and most of its varieties and 

 some closely allied forms, as barn-yard mosquitoes breeding 

 in manure water. In the plate is shown a typical breed- 

 place, where a sufficient number of eggs were deposited every 

 day during the season to more than supply each inhabitant of 

 the city with a mosquito of this species alone, aside from the 

 more dangerous species of Anopheles and others. The obser- 

 vations made in this combination of neglected door yards and 

 manure yards for three stables during the summer of 1904 and 

 1905 show the percentage of adults produced from a certain 

 number of eggs deposited to be sufficient also to supply the 

 eastern section of Pennsylvania with C. pipiens mosquitoes. 



In one yard was found a nest of 3 rain barrels, in the other 

 were two, making 5 rain barrels, 3 manure piles, 3 water 

 closets and some tin cans, agate-ware pots, etc. , containing 

 water with larvae. In the left hand corner of the stable yard 

 is shown a portion of a manure pit containing water from 

 which a one gallon dip, taken last October, brought over 2000 

 C. pipiens larvae, which furnishes an idea of its contents. The 

 water in one of the rain barrels when first seen was so packed 

 with larvae that for over one-half inch from the surface it was 

 about the consistency of gelatine. One of the most interesting 

 facts with reference to the breeding habits in the rain barrel as 

 compared with the manure water is the choice of the various 

 species or varieties of species under the shield of C. pipiens. 

 In the number of larvae mentioned there were 14 distinctively 

 •characterized species, which resulted in five separate forms of 

 adults which were not found breeding in the rain barrels so 

 close by. 



