INJURIOUS INSECTS OF 1904. 



89 



with which we have had experience, and is a serious objection to their 

 use. Nevertheless, once understood, and frequently tested in the 

 field, these machines do good service. 



Our Kero-water outfit arrived too late in the season to be of 

 really practical benefit. It was used August 5th for the first time, and 

 Kero-water of 15 per cent applied. At that date the hoppers were 

 becoming decidedly less in number, and further, the pump could only 

 supply liquid sufficient to fill the lower nozzles. This difficulty was 

 overcome by obtaining another pump, so that next season we will 

 be prepared at the very outset to put up a good, and, I believe, a very 

 successful fight against this pest, which is costing the nurserymen 

 several hundred dollars' loss annually. Mr. Robert Wedge, under 



Fiil. 87. — Cyclone Dust Sprayer. 



whose supervision the spraying was done, wrote this department 

 under date' of August nth, six days after using the Kero-water 

 spray, that he could "see no bad effect on the foliage of the apple 

 trees sprayed with 15 per cent mixture." 



We have already alluded to the statement from Missouri that 

 10 per cent Kero-water mixture appears to be efifective against the 

 adult hopper. In spite of Mr. Wedge's statement that 15 per cent 

 did not appear to injure foliage, from observations along this line 

 at the Experiment Station, the writer is induced to believe that. 10 

 per cent is much safer than 15 per cent in this regard. 



At Adrian, Minnesota, Mr. Fred Mohl, proprietor of a large 

 nursery, has kindly co-operated with the Entomologist, and has 

 been making a series of experiments with the dust sprav. Figs. 86 



