ENTOMOLOGY 97 



Incidentally this reflowing will rid the bog of numerous other pests 

 and may make a material impression on the girdle worm where that 

 is abundant. 



The importance of a sufficient water supply has come to be so 

 generally recognized among advanced growers that in New Jersey 

 miles of ditches tap streams far away from the bogs, and in Massa- 

 chusetts expensive pumping machinery has been installed to raise 

 water in largo quantities to high-bog areas. 



It is sometimes possible to use the upper one of a series of bogs 

 as a reservoir, holding a full head of water as late as it is safe to 

 reflow the lower bogs of the series which have been drawn early. In 

 one series of 100 acres, divided into 5 sections by cross dams, a fall 

 of about 10 feet is utilized to reflow all save the uppermost section, 

 and this practice is possible in almost every case where water is avail- 

 able. 



Sometimes it happens that bogs can be neither winter flowed nor 

 reflowed, and the application of insecticides becomes an absolute 

 necessity. Only arsenics are to be relied upon for good results, 

 although for a long time tobacco was and in some parts of Massa- 

 chusetts is yet the main reliance. It follows from what has been 

 said concerning the habits of the worms that when once they have 

 spun up the tips and are feeding in their cases they are practically 

 beyond the reach of our common insecticides, and that is particu- 

 larly true of the first brood. If there is reason to believe from past 

 experience, or because eggs have been found on the plants, that the 

 early brood will be numerous, spraying must be done just as soon as 

 the vines make a start or not later than the date when the first 

 spun-up tip is seen. The object is to get the poison into position 

 before the leaves are spun up, so that the worms may find their 

 first meal poisoned. If spraying for the first brood is omitted, that 

 for the second brood should be timed in the same way, and, because 

 the worms now spin up a greater amount of vegetation, the chances 

 of killing them off are greater. 



All things considered, the best insecticides for use on cran- 

 berry bogs is arsenate of lead, either in the paste form as sold by 

 certain makers of insecticides or made up by dissolving separately 

 4 ounces 'arsenate of soda and 7 ounces acetate of lead in water 

 enough for that purpose, then combining the solutions in a tank 

 to which 50 gallons of water may be added. If the paste arsenate 

 is used, 1 pound in 40 gallons is better. 



Any sort of machine or pump may be used and any nozzle 

 that makes a reasonably fine spray. The point to be aimed at 

 always is the terminal growth, because it is there that the insects 

 feed. Nothing will be gained by driving the mixture into the 

 body of the vines, especially if they are long and densely matted. 

 The conditions on the bogs vary so much that every grower must 

 determine his outfit according to his own needs. In some cases 

 horses can be used on the bogs to draw a geared machine of laruv 

 capacity; in others they are out of the question; and so the size 



