156 STATE BOARD OF AGRICULTURE. 



in making the applications, or failure to make the application at the 

 proper time. 



It is now recognized that spraying is in no way a cure for the dis- 

 eases and as it must be used as a preventative only, the importance is 

 recognized by all of beginning spraying before the disease has ap- 

 peared and then making sure that not only the fruit but the foliage 

 is at all times covered with the spray mixture. 



For several years serious losses have been experienced from rose bugs 

 by grape growers in the lake shore districts where the soil is of a sandy 

 nature. Attempts have been made to Control them by the use of Paris 

 green and other poisons but from the fact that the principal injury 

 is done to the blossoms, it has been. found impossible to destroy them 

 in this way, especially as they seem to avoid the parts covered with 

 the poison. Hand picking has been resorted to in many cases but it is 

 very expensive and when the insects appear in vast numbers, as is often 

 the case, serious injury is often done to the crop before they can be 

 destroyed in this way. The use of arsenate of lead has given better 

 results as it is possible to use a greatly increased amount of arsenic 

 and in this way the insects are poisoned before very much harm has 

 been done, but even with five pounds of arsenate of lead in fifty gallons 

 of water, it sometimes happens that the insects are so numerous that 

 a large portion of the crop is destroyed. 



During the year we have been experimenting with arsenate of lead 

 used at the rate of five pounds in fifty gallons together with one quart 

 of molasses. The insects prefer this to the blossoms and as they sip 

 up the sweetened water they take in the poison and are destroyed 

 with less injury to the plants than when poison has been sprayed upon 

 the portions they are eating. 



A much cheaper remedy and one that is nearly as effectual is made 

 by substituting arsenite of lime for the arsenate of lead. This is pre- 

 pared by dissolving the arsenic by boiling one pound of arsenic and 

 one pound of sal soda in one gallon of water until the arsenic has been 

 dissolved. This is then diluted to five quarts and one quart of the 

 solution, one pound of slaked lime and one quart of black-strap 

 molasses used with fifty gallons of water. 



We have also been carrying on quite extensive experiments to discover 

 the value of arsenate of lead as a substitute for Paris green and other 

 arsenicals and have been well pleased with the results. The better 

 brands contain about sixteen per cent of arsenious oxide or about one- 

 third as much as is found in Paris green. Hence if one pound of 

 arsenate of lead is used for fifty gallons of water or Bordeaux mixture 

 it will furnish the same amount of arsenic as will be provided by five 

 ounces of Paris green, wliich is about the usual amount used. Arse- 

 nate of lead, however, has the advantage of being practically insoluble 

 and hence it is possible to use a much larger amount if neoded and 

 we have found that it is generally well to use one and a half to t«'o 

 pounds for fifty gallons for most insects. There are cases, however, 

 when four or five pounds may be desirable. Arsenate of lead also has 

 the merit of being very adhesive and when thoroughly applied to a 

 tree the occasion for repeating the application will be much less than 

 when Paris green, which readily washes off, is used. In fact, considering 

 the arsenical alone, it is possible to lessen the number of applications 



