1919.'] 



SUPPOSED CURE FOB FROGHOPPEBS. 



13 



round the base of the stools) the whole was put on one small patch 

 which I found to contain about 270 stools. This is therefore at the rate 

 of 4|- stools per gallon — or about 550 gallons per acre with 2,500 stools 

 per acre ; which at 6 cents per gallon would cost $33 per acre for 

 material alone for one application. 



If one gallon of liquid to 20 or 30 stools is sufficient to reduce the 

 number of froghoppers below the danger limit, an application at this 

 phenomenal rate might be expected to exterminate them completel3\ 



On November 21 Mr. Glasgow and I examined the plots. There 

 was no visible differences between the treated and untreated canes,, 

 both of which was slightly but not badly blighted. 



We then examined the stools 

 and counted the number of 

 nj-mphs visible on the surface. 



On 120 treated stools at A 

 we found 25 nymphs. 



On 120 treated stools at B 

 we found 37 nymphs. 



On 120 untreated stools 

 at C we found 45 

 nymphs. 



The application had reduced 

 the number of nymphs from 45 

 to an average cf 31. 



"TRACE 



Fig. III. 



About 60 per cent, had survived the application. 



As many of the survivers were quite young there is no doubt that 

 the application had not destx-oyed all the eggs. 



Eoot disease was not uncommon on both treated and untreated 

 areas. 



It must be admitted that there were very few froghoppers even on the 

 untreated portions and that, no doubt, if there had been more none 

 would have been destroyed. But the value of the treatment depends 

 largely on whether or not it is applicable before the numbers of the 

 froghoppers have reached the danger limit. 



Cedar Hill. 



On November 1 a portion (exact limits not marked) of 

 Field No. 106, 1st ratoons B 156, was treated by Mr. Glasgow 

 "with his preparation (exact quantity not recorded). 



