148 BOARD OF AGRICULTURE. [Pub. Doc. 



a chemical reaction will take place, forming arsenate of lead 

 as a fine white powder in suspension in the water. If cold 

 water be used, the solution of the acetate of lead will require 

 fifteen minutes or more ; but if the water be hot, the sub- 

 stance will dissolve very quickly. I do not need to remind 

 you that arsenate of lead is poisonous, and should be used 

 with the same care as Paris green. I have lieen somewhat 

 explicit in describing the preparation and use of arsenate of 

 lead, as I believe it to be the best insecticide we have at the 

 present time, not only for cranberry insects, but also for 

 all leaf-eating insects.* So far as our observations go, 

 arsenate of lead is not washed oft' from the foliage by 

 showers so easily as Paris green, and more or less of it 

 remains for a long time. 



The Fruit Worm. 



The fruit or 1)erry worm (^Mineola vaccinii) appears on 

 the bogs about the time the berries are beginning to set, 

 from the first to the middle of July, according as the season 

 is early or late. The female lays an q^^ at the blossom 

 end of the young berry, often beneath one of the triangular 

 lobes of the calyx. This egg hatches in five or six days, 

 and the young fruit worm feeds for a day or two on the out- 

 side of the berry before making its way into the interior of 

 the fruit. If the vines be sprayed at the time these eggs 

 are hatching, or a day or two earlier, the first meal would 

 prove fatal to the worms, and I have no doubt would 

 destroy a large percentage of them, just as in the case of 

 spraying apple trees for the destruction of the codling moth. 

 Whether it will pay to spray for this insect will depend 

 upon their abundance. If there are but few on a bog, it 

 would not be worth while ; but if they are abundant, it 

 would undoubtedly be wise to spray the vines with an 

 insecticide. 



* This detailed statement of the method of preparing arsenate of lead will serve 

 as a further explanation of the recommendations given in Bulletin No. 24. Later 

 experience has shown that it is usually desirable to use a greater quantity of the 

 insecticide to one hundred and fifty gallons of water than is here mentioned, as will 

 be seen by recommendations on page 146 of this volume. In siich cases it is neces- 

 sary to adhere strictly to the relative proportions of the ingredients and manner of 

 mixing as given above. 



