CRANBERRY GROWING 



31 



Fig. 26. Cranberry Bog Infested with Root Grubs. 

 The bare patches are a result of their work. 



Fig. 27. Treating Root Grubs with Sodium Cyanide Solution. 



for twelve hours kills the worms after they are a third grown. Dusting infested 

 bogs and their surrounding uplands with 5 percent DDT dust whenever the 

 worms are at work is highly effective. 



The cranberr}' girdler seldom infests areas kept well sanded; it works chiefly 

 in the trash of unsanded bogs among thick vines. Complete flowage after pick- 

 ing, beginning by September 25 and continuing for a week, is a good control. 

 Complete flooding tor about twenty hours, the last of August or early in Sep- 

 tember, to checl' a severe attack is sometimes advisable, especially with the Howes 

 variety. A serious infestation can be largely controlled by dusting with 10 

 percent DDT dust or with high-grade pyrethrum, 50 pounds to an acre, two or 

 three times at four-day inter\als in earh- to mid June, to kill the moths. 



