December, '16] DUTCHER: FROZEN LEAD ARSENATES 561 



Reported Occurrences 



Dade City, Fla. Injury to privet. W. W. Yothers. 



Olando, Fla. Privet hedges largely defoliated in the fall and spring 

 of 1913. W. W. Yothers. 



Charleston, S. C. Much damage to privet in 1913. W. W. Yothers. 



Auburn. Ala. IVIuch defoliation and damage to privet hedges. Dr. 

 W. E. Hinds. 



Agricultural College, Miss. Considerable destruction to privet 

 hedges on the campus and at other points in Mississippi. R. W. 

 Harned. 



Baton Rouge, La. Defoliation of privet. E. S. Tucker. 



Batesburg, S. C. Frequently inflicts severe damage to privet 

 hedges. Author. 



Control 



Several insecticides have been tested against this species. Lime 

 sulphur gave practically complete mortality. Following are the results 

 of the test. 



Sprays Mortality 



Lime sulphur (Thomsen Chem. Co.) 99% 



Potassium sulphid v^0% 



Nicotine sulphate Less than 5% 



SOME EFFECTS OF FREEZING ARSENATE OF LEAD PASTES 



(Preliminary Pajper) 



By R. Adams Dutcher, Department of Chemistry, Oregon Agricultural College, 



Corvallis 



Introductory 



From time to time inquiries have been received at the Oregon 

 Experiment Station relative to the use of arsenate of lead pastes which 

 have been frozen during the winter months. Fruit-growers have 

 observed in certain instances that the appearance of the pastes after 

 freezing was different from the unfrozen material and some men have 

 even insisted that the insecticidal value of the spray had been impaired 

 by freezing. 



Manufacturers of some of the commercial pastes advise that all 

 frozen materials be shipped back to the factory or thrown away; 

 while others maintain that freezing has no effect on their product. 



The same question was brought to the writer's attention while 

 teaching the chemistry of insecticides to a class of agricultural students. 



