232 EXPERIMENT STATION. [Jan. 



present in considerable nnmbers. When this ])eriod is not too 

 much prolonged, it is often possible, at least on small bogs, to 

 control a heavy infestation fairly well with either a single good 

 spraying or a single early June reflowing. 



The most successful treatment with water, all conditions con- 

 sidered, which the writer knows of, was applied on one of the 

 large bogs during this season. The winter flowage was held 

 until the 2d of June, from which date the bog was without flow- 

 age or any special treatment until the 25th of the same month, 

 when it was completely reflowcd for two days. Before this re- 

 flow the bog was heavily infested, but after it only a very few 

 fireworms were seen throughout the season. This bog is com- 

 pact in shape and covers about 160 acres. A considerable por- 

 tion of it is heavily vined, and the infestation was spread pretty 

 well over it. The most reasonable explanation of the success 

 of this treatment appears to be the following one : — 



In the water of the winter-flowage there was perhaps not so 

 great a diiference in temperature between the tops and the bot- 

 toms of the vines, especially where they were thick, as there 

 would have been had they been exposed to the air as well as to 

 the sun. Under these conditions all the fireworm eggs present 

 were perhaps influenced in their development much more equally 

 by the rising temperature of the spring days than they would 

 have been without the flowage. The eggs were probably thus 

 brought nearly to the hatching condition fairly well together, 

 and then the water was taken off so that in this condition they 

 were at once exposed to the hot weather of June, which naturally 

 hastened rapidly the remaining development of all of them. By 

 this means the hatching was so bunched up that when the bog 

 was reflowed twenty-three days after the winter flowage was let 

 off practically all the eggs, on thick vines as well as on thin 

 ones, had hatched, and the insects were almost entirely in the 

 caterpillar (worm) stage, the stage in which they are most 

 readil}^ drowned. 



Possibly this method of treatment will not always prove as 

 successful as it did in this case, but the conditions attending 

 this trial were such that the results should probably be consid- 

 ered significant. This method should be tried further where 

 badly infested bogs can be reflowcd in June. Moreover, if the 



