BLUEBERRY INSECTS IN MAINE. 265 



METHODS OF CONTROL. 



While the actual number of maggots in 250,000 acres liter- 

 ally blue with berries when they are ripe must be very large, 

 ordinarily only an insignificant proportion of the fruit is infested. 

 This was the case in 1913, when the crop was fairly large, and 

 though the maggots were abundant only from i to 2 per cent ni 

 the crop had been attacked. But in 1914, though the larvae 

 were far less numerous so small was the yield that from 8 to 

 10 per cent of the fruit was maggoty. Conditions were much 

 the same in 191 5, owing to a short berry crop, although as 

 Rliagoletis is more or less locally distributed on the plains, it i? 

 very hard to make even an approximate estimate. 



No measures aimed at a complete control of this pest 

 would prove really practicable and in an ordinary yield no 

 elaborate system of control is needed. The maggot could never 

 be exterminated in so vast an area of wild land, most of it 

 remote from any town and broken up by swamps, lakes and 

 occasional forest tracts, even if concerted efforts were made, 

 for of necessity there would always remain many places in which 

 the flies would breed uninterruptedly and from which they 

 would spread again over the rest of the barrens. Nor does it 

 seem practicable to advocate poison spray and volatile oils for 

 an area of 400 square miles, even if there were no doubt as to 

 the efficiency of these agents. 



Burning the plains as is commonly done is a practice highly 

 tc be commended. Besides restoring the fertility of the land, 

 it undoubtedly destroys the puparia in the soil for they lie near 

 the surface, and it must be a very material help in keeping down 

 the numbers of the fly. It also serves to kill many other insects 

 for wherever there is "new burn" the bushes are conspicuously 

 free from leaf-feeding insects of all kinds. As approximately 

 only one-third of the plains is burned yearly, the fly is not ex- 

 terminated, and this probably could not be accomplished even if 

 an attempt were made to burn over the whole extent of the 

 barrens at one time. 



When the berries are winnowed in the field the maggots can 

 be found abundantly. A great many of the larvae are blown 

 out with the lighter dirt and can be caught in one of the trays 

 in which the berries are packed. Frequently a good many larvae 



