21 



the Iowa Experimeut Station. A strawberry patch infested with the 

 green strawberry slug {Monostegia ignota Or.) was thoroughly sprayed 

 with London purple ((tne pound to 200 gallons of water), and within a 

 week after this application Mr. H. A. Gossard and other employes of 

 the station "ate very heartily of the ripened fruit " without experienc- 

 ing any ill effects whatever. This matter is fully discussed in Bulletin 

 No. 18 of the Iowa station, and in Entomological Neii-s (vol. iii, p. 

 230), and the general subject of the danger of poisoning from the con- 

 sumption of fruit and vegetables sprayed with arsenicals is considered 

 in Farmer's Bulletin No. 19 of this Department. 



In accordance with my suggestions, Mr. B. E. Behrend made some 

 experiments with the kerosene emulsion and, at his own instance, with 

 Paris green, and kindly reported results. 



Experiments with Kerosene Emulsion and Paris Green. — The kerosene- 

 soap emulsion, diluted with 10 parts of water, was sprayed on the vines 

 May 5 and G (1893), an ordinary spraying syringe being used for the 

 purpose. May 8, when I visited the held, a few beetles were still on 

 these vines, but the difference in their numbers and of those that were 

 at work on the check plats was quite perceptible. The application was 

 made too late to be of substantial value, but it served to show that the 

 emulsion was of some value as a repellant. 



The present year work was begun earlier, and with better success. 



The field treated was divided into five parts. 



Plats 1 and 2 were of the " Charles Downing" variety, of equal size, 

 and contained about the same number of plants. Plat 1 was sprayed 

 with Paris green April 26 and 29, May 3 and 6. Plat 2 was treated 

 with kerosene emulsion April 29 (threatening and rainy weather pre- 

 venting earlier spraying). May 3 and 6. As a result, double the num- 

 ber of berries were picked from plat 1 as from plat 2. 



Plats 3 and 4 of the " Sharpless " variety were treated in a similar 

 manner to 1 and 2, but the presence of blight prevented an exact esti- 

 mate of the result. Plat 5, or half of the entire field, of "Charles 

 Downing" variety, was treated with Paris green, with the result that 

 only a few buds were found to have been cut! 



Mr. Behrend also reported that a neighbor of his applied Bordeaux 

 mixture with some success. 



It should be said that while the above experiments were of value in 

 showing the efficacy of Paris green and its superiority to kerosene emul- 

 sion, still the fact that the emulsion was not applied until three days 

 later than the Paris green nuist be taken into consideration, as this 

 undou.btedly affected the result. 



Directions for the Application of these Insecticides. — The following sug- 

 gestions are substantially as given to our correspondents during the 

 past two years. To obtain the best results it is necessary to spray the 

 vines a day or two before blooming, and again two or three days after 

 first bloom, at least three applications being made at intervals, the dif- 

 lerent applications being graded with a view to keeping the plants 



