460 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



at the rate of 1-400 plus lime-sulphur 1-35, fifty trees sprayed; white 

 hellebore 2 lbs. to 50 gallons of lime-sulphur 1-35, fifty trees sprayed; 

 triplumbic arsenate of lead, 3 lbs. to 50 gallons of lime-sulphur 1-35, 

 sprayed 100 trees. The rest of the orchard was sprayed with regular 

 neutral lead arsenate 2 lbs. to 50 gallons of lime-sulphur 1-35. A few 

 cherry trees were also sprayed with this material to test for burning 

 properties as well. 



The results of these preliminary experiments showed that due to our 

 excessive rains at intervals the Black Leaf 40 and white hellebore, when 

 used with lime-sulphur, cannot be relied upon as they are subject to 

 being washed away. A short while after the trees were sprayed the 

 foliage upon examination was very badly eaten into and many of the 

 small fruits pitted. In check experiments carried on at Corvallis 

 where the beetles were confined in cheesecloth bags over apple trees, 

 it was found that the beetles did not seem to mind the Black Leaf 40 

 and white hellebore when used alone and ate very voraciously of the 

 foliage. At Salem, Oregon, it was observed that the regular arsenate 

 of lead when applied in greater strengths than 2 lbs. to 50 gallons of 

 lime-sulphur 1-35 cannot be used with safety on the tender cherry 

 foliage. The triplumbic arsenate of lead gave very good results and 

 may be used in greater strengths than the regular neutral arsenate of 

 lead on cherry and prune foliage. The Italian prune trees where the 

 arsenate of lead was used were less riddled, the prunes were cleaner from 

 pitting and occasionally one or two beetles could be shaken from the 

 trees. The arsenate of lead, both triplumbic and the regular neutral, 

 showed very good adhesive properties when used with lime-sulphur 

 and the foliage was well coated two weeks after the applications in 

 spite of our excessive hard spring rains. It is possible that the tri- 

 plumbic arsenate of lead may be used at greater strengths than was 

 used with good results on the foliage of cherry and prune. 



In this state where the brown rot of stone fruits, Sclerotina fructigena, 

 is prevalent and spraying operations must be conducted against it 

 in the case of cherries and Italian prunes and plums, combination 

 spraying should be practiced more extensively, in those sections where 

 the two evils exist. 



In the case of prunes, plums and cherries which are sprayed for 

 brown rot just after the blossoms open with Bordeaux Mixture 4-4-50 

 or lime-sulphur 1-35, arsenate of lead should be added 3 lbs. to 50 

 gallons of the spray, and preferably the triplumbic arsenate of lead as 

 the foliage of cherry particularly is very susceptible to arsenic injury. 

 In the spray against brown rot and Coccomyes (Cylindrosporium), 

 the leaf spot or shot hole to be applied 10 da3^s or two weeks after the 

 shucks fall, add arsenate of lead 3 lbs. to 50 gallons of the spray. At 



