47 



])iimp 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 pnt np a good and, I 

 hope, a successful light against this pest, which is costing the nursery- 

 men several hundreds of dollars loss anmially. 



At Adrian, JNlinn., Mr. Fred Mohl, proprietor of a large nursery, 

 has kindly cooj^erated Avith the Entomologist, and has been making 

 a series of experiments with the dnst spray. Mr. Mohl sprayed 

 twice with the " caustic lime " mixture, and once with the " general 

 formula." At the date of my visit, July 12, the trees were looking 

 very well, though they were not free from leaf-hoj)pers. Mr. ^lohl 

 is of the opinion that, if he had begun earlier, " before the hoppers 

 appeared," as he expressed it, and sprayed three times, he could have 

 kept them Avell under control. ^AHiile tlie writer is quit^ Avilling to 

 be convinced, he has not absolute confidence in the efficacy of dust 

 spraying in this connection. 



I believe the possibilities foreshadowed in the success of the cart 

 as a sprayer are almost unlimited. A cart to straddle one row and 

 spray the straddled row and the two adjoining rows could be 

 easily constructed. These carts, too, including the one we are now 

 using, could be made automatic by connecting the pumps with the 

 wheels by proper gearing. 



Mr. Smith concurred in. the view that kero-water pumps were in 

 general unreliable. He hoped that experiments already under way 

 on the production of so-called " soluble petroleum " would solve the 

 difficulty. 



Mr. Slingerland said that in New York they had gone through 

 similar experiments for the leaf-hopper on grape vines. With diluted 

 kerosene emulsion or whale-oil soap the young hoppers were easilv 

 killed, l)ut the only vay to kill the adults was to first get them off 

 the vines. They were knocked down by a 5 per cent kerosene sprav, 

 but they would recover from this; consequently it was necessary, 

 while they were on the ground, to spray again Avith a 25 per cent 

 mixture. 



Mr. Sanderson said that he had failed to find any satisfactory 

 form of kero-water pump. 



Mr. Osborn said that he had killed some species of hoppers on 

 potatoes with 5 per cent emulsion, but it Avas necessary to keep them 

 in the air for this to be efi^ective. 



INIr. Fletcher called attention to the fact that hoppers might often 

 be fatally injured eA^en though they appeared all right for a time 

 after the spraying, death occurring later, lie said that Mr. Lugger 

 had killed grasshoppers by dipjjing one leg in kerosene. 



