1918 



ENTOMOLOGICAL SOCIETY. 



37 



judged by this year) the larvffi of the first brood are for the most part full grown, 

 and have begun to leave the mines and enter the soil, where they construct a 

 firm little oval earthen case about 5 mm. long by 4 mm. wide. Inside this they 

 pupate. The cases found were from 1 to 2 inches below the surface. The 

 adults of the second brood begin to appear after a couple of weeks and this 

 year were still present in countless numbers by September 2ist. Egg-laying 

 was then at its height. A few larvse of the second brood can be found in leaves 

 as long as these remain green. I found them at St. Catharines one year near 

 the end of November. Most, however, have entered the soil long before this and 

 constructed their earthen cocoons. The winter is passed in these in the larval 

 stage. 



Fortunately, this pest does not begin to injure the leaves until two or three 

 weeks before the fruit begins to ripen, and much of the fruit, at least this year, 

 was off before the mines of the second brood were made. Yet in spite of these 



Work of Blackberry iLeaf Miner. 



factors the insect must do considerable damage in the way of weakening the 

 plants and lessening next year's crop. It certainly makes the owner much 

 alarmed lest it will ruin all his plants. 



Methods of Conteol. Cultivation of the soil in late fall and the early 

 part af the next season suggests itself as a practicable method of control, but 

 is ineffective; probably because the cocoons are not easily broken. 



It has been suggested by some writers that kerosene emulsion would penetrate 

 the dead portions of the leaf and kill the larvfe, but it does not do so. Black- 

 leaf 40, as shown by Herrick, will kill the larvse of some Saw-fly Leai-miners in 

 their mines, but it has no effect upon this species. 



Having failed to kill the pupne or larvre I next thought it possible to poison 

 the adults. These apparently remain exclusively on the leaves and find their 

 food there. I do not remember seeing one anywhere else, not even on the fruit, 

 neither does Mr. Alton. Accordingly I made a preliminary test of spraying the 

 leaves with sweetened arsenate of lead and to my delight the adults could almost 

 at once be seen feeding upon it. Encouraged by this, I' assigned to Mr. Alton the 



