146 BOARD OF AGRICULTURE. [Pub. Doc. 



after it is drawn off before they hatch, so that we may have 

 the vine worm in all stages of growth at the same time on a 

 bos: where these conditions have occurred. The first brood 

 of vine worms does not appear to be numerous enough to 

 cause a great deal of damage, so far as I have heard, but 

 they give rise to a progeny in the second generation which 

 is perfectly appalling. I have walked over bogs on Cape 

 Cod where at every step the moths of this species flew up by 

 the hundred, only to settle down again as soon as I had 

 passed. I do not wonder, in cases where the moths are so 

 numerous as this, that the vine worms hatching from their 

 eggs should be abundant enough to devour every leaf on the 

 vines. It is because of these varying conditions that the 

 cranberry growers are sometimes at a loss to know just 

 when to apply insecticides. 



In dealing with this insect I would strongly advise those 

 in charge of the bogs to watch carefully for the hatching of 

 the eggs, and as soon as the young begin to appear, to spray 

 the vines with arsenate of lead in water in the proportion of 

 two or three pounds to one hundred and fifty gallons, adding 

 two quarts of glucose, to aid the insecticide in adhering to 

 the leaves. In my bulletin on cranberry insects published 

 in May, 1892, I recommended the use of Paris green, and 

 made no reference to arsenate of lead, which was not dis- 

 covered till in the summer of 1892, after the publication of 

 that bulletin. Since that time this new insecticide has been 

 tested so thoroughly, both in this State and elsewhere, that 

 I have little hesitation in expressing the belief that it will in 

 time entirely supersede Paris green as an insecticide. I gave 

 a full account of arsenate of lead and the experiments per- 

 formed with it in Bulletin No. 24, of the Hatch Experiment 

 Station, published in April, 1894. Since that time the gypsy 

 moth committee has used several tons each year in destroy- 

 ing the gypsy moth, and I am informed that it is now very 

 generally used by farmers and fruit growers in New York, 

 New Jersey and elsewhere. The use of this insecticide has 

 now gone beyond the experimental stage, and our knowledge 

 of it is as exact as that of Paris green. 



The advantao;es of arsenate of lead are that it remains in 



