N. J. Mosquito Extermination Association 57 



The catches or collections are made in the usual manner at cer- 

 tain agreed-upon stations, where, as far as possible, similarity of 

 conditions exist. The specimens thus taken are turned in for 

 identification, and each station is credited with the result of the 

 findings. 



The purpose of these catches was to ascertain the kind and 

 number or quantity (technically called density) upon the theory 

 that the findings would serve as a guide in the work and as a basis 

 for computing the percentage of the different prevailing species. 

 The new thought appears to be that with this knowledge breeding 

 places can be located and future breeding prevented. Doubt has 

 been raised as to the efficiency of this new thought, and the inten- 

 tion of this presentation is to show that night collections, except 

 for scientific purposes, are neither practical nor economical. 



THE THEORY. 



Water being necessary for the propagation of mosquitoes, it 

 follows that so long as favorable conditions exist it is probable 

 that these insects will escape periodically, and because it is not 

 always known where these breeding places are, it is suggested 

 that ''night collections" would help to solve this problem. The 

 belief is that these insects fly from a given point in a fan-like 

 manner and that by tracing back through the process of elimi- 

 nating the catch of stations showing the lesser density, there 

 would finally remain but the one station showing the greatest 

 number. This final station, like the base of the fan, would indi- 

 cate the breeding place from which the mosquitoes escaped. 



So far as is known there are no references in the existing 

 text books to this method of locating breeding placx of the 

 mosquito, yet that is no reason why this idea should no. be re- 

 corded in the text books of the future, for Shakespeare says, 

 ''There are more things in heaven and earth, Horatio, than are 

 dreamt of in your philosophy." 



HOW THE THEORY WORKS OUT. 



There must necessarily be some cause for the theory to work 

 upon, otherwise there is no reason for its being. So, we find at 

 the various "night collection stations" adult mosquitoes on the 

 wing, having escaped from some unknown breeding place. If, 

 perchance, it is an invasion of great density, it will be all the 

 easier to find the place whence they came. But, what about the 

 mosquitoes that have escaped? Here they are and everywhere. 

 With these conditions, what is to be expected ? Fault-finding and 



