THE CHEERY LEAF-BEETLE. 23 



Hydrated lime, dusted on trees by hand, was used as a protective 

 measure, and in some instances appeared to be effective. 



Summary of Experiments. 



From the experiments and observations described, the following 

 conclusions may be drawn: 



Arsenate of lead must be used at a rate of not less than 5 pounds 

 to 50 gallons of water to be effective in protecting trees from injury 

 by the cherry leaf-beetle. A mixture to which molasses was added 

 at the rate of 1^ gallons to 50 gallons of the mixture was effective in 

 killing practically all of the beetles which fed upon the trees on which 

 this mixture was applied. This addition of sweetening to the arse- 

 nate has the serious disadvantage of making the spray easily washed 

 off by rains. Arsenate of lead used wi thout molasses was less effective 

 in protecting the trees, although it kOled some beetles and it was to an 

 extent repellent to them. Lime in the amount in which it is added 

 to an arsenate-of-lead spray was not repellent. 



Forty per cent nicotine sulphate applied with water at the rate of 

 1 to 600, with or without soap, was effective as a contact spray. 

 Weaker dilutions of nicotine sulphate and soap-carbolic acid solu- 

 tions, although apparently effective at the time of application, did 

 not have a permanent effect. 



CONTROL OF LARV^. 



If the larvae fed on a cultivated plant, control measures might be 

 directed against it, thus preventing the adults from developing in 

 destructive numbers. But it feeds on a wild plant that is usually 

 present where control measures can not be applied, often on land that 

 is in no way controlled by the fruit grower, and not even in the imme- 

 diate vicinity of fruit farms. Nevertheless the clearing up of cut-over 

 timberland and the destruction of the wild hosts of the larva of this 

 beetle would greatly limit its possibilities of destructiveness. Should 

 the cherry leaf-beetle become a permanent pest, cooperative work 

 along this line might be advisable. 



RECOMMENDATIONS. 



Spray practice for the control of the cherry leaf-beetle at the time 

 of its next appearance in economic numbers can not be absolutely 

 determined from the foregoing experiments. The numbers of the 

 beetles, the duration of the migration, and the weather conditions 

 at the time must qualify any recommendation. More extensive 

 experiments also might modify the results. 



Nicotine sulphate, whUe temporarily effective, does not prevent 

 a new invasion of an orchard on the day following its application. 

 However, its use in peach orchards is recommended, for the greater 



