202 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



been able to find that Bordeaux alone had been used at the same time 

 and under the same conditions. In other words, though Nicotine 

 Sulphate may be used in combination with Bordeaux, it will probably 

 not prevent any injury that the Bordeaux would cause if used alone. 

 This fact, however, need not affect the recommendations for com- 

 bining the two sprays. 



Successful Use of the Combination by Others. — -Though the. 

 general attitude was conservative and the combination not generally 

 recommended, records of its successful use were beginning to accu- 

 mulate. 



A few of the following records were published, but most of them 

 were obtained through correspondence in answer to letters of inquiry. 

 (This is not intended as a complete list but includes merely instances 

 that have come to our attention.) 



Professor Watkins, University of Illinois, has used the combination 

 for five years with excellent results.^ 



W. B. Parker, Bureau of Entomology, used the combination for the 

 hop flea beetle in 1909. No leaf injury was reported and the insec- 

 ticidal properties of the combination were retained. The author con- 

 sidered that where the beetles were numerous and a large percentage 

 around the vines, a Bordeaux-tobacco mixture should prove effective.^ 



Fred Johnson, Bureau of Entomology, used the combination success- 

 fully in 1911 on nj^mphs of the grape leaf hopper.^ 



Hartzell, New York Experiment Station, used the combination 

 successfully for the nymphs of the grape leaf hopper in 1912.* 



Beach, Iowa Experiment Station, in 1912 recommended the com- 

 bination and that soap be not used with it.^ 



Sanderson,^ in his book Insect Pests of Farm, Garden, and Orchard," 

 states that tobacco extracts may be added to Bordeaux mixture to save 

 a separate application. 



G. P. Gray, Chemist, California State Insecticide Laboratory, 

 examined our laboratory methods and records and stated that the 

 experiments seemed to be quite conclusive. Professor Gray's tests 

 showed that no soluble copper was produced by mixing Bordeaux with 

 the ordinary tobacco extracts found upon the market.^ 



Professor M. B. Waite tested the combination last summer on canta- 

 loupes on his own farm. No foliage injury occurred and the Bordeaux 



^ In correspondence. 



2 Bureau Entomology, Bui. 82, pt. IV. 



2 Bureau Entomology, Bui. 116, pt. I. 



Xew York (Geneva) Station Bui. 359. 

 s Iowa Station Bui. 127. 

 « Page 608. 



