80 NATURE-STUDY REVIEW [12:2— Feb., 1916 



It seems little short of murderous, according to recent observa- 

 tions (or experiments?) to let the flies kill the babies in one New 

 York City block, while some attempt is made to control them 

 in another, if the flies might have been eliminated from both 

 blocks. 



Fly campaigns are never started early enough in the season. 

 One manual training class took nearly three months to make one 

 fly trap apiece. Any boy, handy with tools, ought to make the 

 trap described below, the first one in at most two hours and subse- 

 quent ones in less than one hour apiece. We ought to take a few 

 sharp lessons on the fly early in the fall, when they are most 

 troublesome, and then get our traps and nets all made during the 

 winter and so have them ready to use with the first move of the 

 enemy in the spring. It is slowness in starting in the spring, 

 which allows fly breeding to begin, that is fatal to complete suc- 

 cess. Another common mistake is to waste too much time and 

 give too much attention to breeding material. No amount of 

 this can ever produce a single fly, if there are no breeders to lay 

 their eggs in it. By strict attention to the over-wintering breeders 

 isolated homes may be so completely rid of the pests that screen 

 windows and doors may be dispensed with and meals enjoyed on 

 unscreened porches with not a single fly at the table, while homes 

 near by are swarming with them. Even under city conditions, 

 Dr. Jean Dawson, co-operating with the school children, freed 

 residence sections of Cleveland of flies so that the writer did not 



Fig. 2 — Stable Window Fly Trap. Set one week. 



