Report of the State Entomologist 291 



tation upon the proper time for arsenical spraying, that the danger to 



bees from visiting the blossoms should be positively determined. The 



possibility of their being poisoned in this manner, or collecting 



poison that may be communicated to the honey, is questioned by 



some of our best botanists. Will not some of our Agricultural 



Experiment Stations make a study in this direction the coming 



season ? 



London Purple, or Paris Green ? 



"The seasonal conditions of last year [1889] were such that the 

 foliage was badly affected iu many instances after having been 

 sprayed with London purple. Although most of the injury observed 

 was doubtless chargeable upon one or more of the fungous diseases 

 that were unusually prevalent, it is at the same time possible that the 

 foliage was more susceptible to injury from London purple than in 

 ordinary years. 



"After the experience of last year several of our fruit-growers, 

 who have been in the habit of using the purple, will, the present 

 year, abandon it for Paris green. Whenever this arsenite is used 

 care should be taken that the liquid be kept in continual agitation, so 

 as not to permit it to become of unequal strength through its speedy 

 settling. The purple is much more easily held in suspension, being a 

 lighter powder. 



" In favor of London purple, it may be stated that Entomologist 

 Weed of the Ohio Agricultural Experiment Station, has used, without 

 injury to the foliage, one pound of the purple to one hundred gal- 

 lons of water, in protecting cherry trees from curculio attack, saving 

 thereby 75 per cent of the fruit liable to injury. The same result 

 was obtained by spraying two or three times with the weaker mixture 

 of one pound to one hundred and sixty gallons of water. 



"Although methods of spraying are not yet perfected, and each 

 season's experiments are giving us important information regarding 

 it, the success attending it at the present is so marked and so great 

 that no fruit-grower can afford to dispense with arsenical spraying." 



Strength of Mixture. 



Replying to the question, how strong a mixture should be used : 

 " One pound of Paris green to two hundred gallons of water may 

 safely be used on apple and cherry trees; one pound to two hundred 

 and fifty gallons for the pear and plum, which are more sensitive, and 

 one pound to three hundred gallons for the apricot, presuming it (in 

 the absence of any direct experiments) to be almost as readily affected 

 as the peach. 



"If experiments shall satisfactorily prove that our fruit trees will, in 

 general, bear a stronger liquid than the above — in this event, for 



