CAPE COD CRANBERRY INSECTS 



43 



Brown Cranberry Spanworm. 



Fig. 31. Eggs among litter from bog floor. 

 Much enlarged. 



Treatment. 



June reflooding interferes enough with tlie i)r(igres.s of the inotlis onto a 

 bog and tlieir egg laying there to prevent the development of an infestation 

 where it is practiced regularly. Complete flooding for 36 hours as soon as the 

 moths reach the height of their flight often very nearly eradicates a bad in- 

 festation, but tliis cannot be relied on. 



It seldom is practicable to flood a Ijog wiien the worms are active. A spray 

 of 6 pounds of dry lead arsenate in 100 gallons of water is very eifective, 

 especially if applied wliile the worms are hatching. 



If tlie moths have been flying in great nvmibers, the vines should be exam- 

 ined with an insect net daily from about June 20 till the worms begin to 

 hatch. Then spraying should begin at once and all the infested area be treated 

 in two day.s, even if it takes several spraying outfits. These worms sometimes 

 give a net count of over 2000 to 50 sweeps, and such an infestation can de- 

 stroy a fine crop promise within a week after hatching begins. 



