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STRUCTURE, CLASSIFICATION, 

 AND KEYS 



FfiOM THE STANDPOINT OF MOSQUITO SUPPRESSION, a knowledge of 

 mosquito species is invaluable. Not only are the necessary control 

 methods determined by the habits of the specific troublesome species but 

 one cannot reach a true estimate of the results of the work without this 

 knowledge. Since mosquitoes fly, or are wind carried, often for some dis- 

 tance, locality is not a determining factor. If the troublesome. mosqui- 

 toes are really salt marsh species, a knowledge of that fact would pre- 

 vent the useless expenditure of time and money on control of local 

 breeding. If, in spite of all work which a municipality can do, locally it 

 is overrun with mosquitoes a knowledge of that species will enable one 

 to trace them to their breeding place. Very essential is a knowledge of 

 external anatomy which will help one to understand the artificial keys 

 used in separating the species. 



In order to determine the species by its appearance familiarity with 

 characteristic marks is important. Much the same thing is true of class- 

 ifying the larvae. The inability of the larva to migrate is offset, to some 

 extent, by the ubiquitous breeding habits of certain species. In general, 

 the woodland species are found in woodland pools ; the swamp species 

 are likely to be prevalent in the swamps. The malarial species are likely 

 to breed in reasonably clear water along the overgrown banks of 

 streams, pools, and small lakes. In stagnant pools in the open or about 

 human habitations house mosquitoes are likely to be prevalent. The 

 salt marsh is the likeliest home of the salt marsh species. But there is 

 sufficient overlapping of one species on the territory of another to 

 keep the student constantly on the lookout for the unexpected. 



Adult or perfect mosquitoes can be successfully classified only when 

 they are killed without crushing. For identification the mosquito is in 

 the best condition when it has emerged from the pupal shell and has had 

 time (twenty-four hours) to harden. From that time forward, the mark- 

 ings decrease in clearness through fading and rubbing until, in speci- 



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