THE CRANBERRY GIRDLER. 



13 



the moths, frightened from the vines, rose into the air the swallow 

 darted foPthem and captured many. 



At present, natural enemies do not appear to be potent factors in 

 the control of the girdler on cranberry bogs. 



REMEDIAL MEASURES. 



Under the heading of remedies fall such methods of treatment as 

 spraying, the use of repellents, burning, trap lights, flooding, and 

 sanding. Of these measures, flooding and sanding have given the 

 best satisfaction, as indicated by the work conducted in New Jersey. 



SPRAYING. 



Owing to the habit of the larvae of feeding on roots and runners 

 under cover of the trash beneath the vines, there seems to be no hope 

 of developing a method of combating them in which reliance can be 

 placed on spraying. In addition to the trash which hides the larvae, 

 the dense mat of vines covering the bog prevents a large portion of 

 the spray material from reaching even the trash. 



REPELLENTS. 



It has been suggested occasionally by growers that commercial 

 fertilizers might act as repellents of the girdlers and at the same 

 time stimulate the vine growth. The opportunity to study this 

 method of treatment was afforded at Whitesbog, N. J., where fer- 

 tilizer experiments on cranberry bogs have been carried on by the 

 New Jersey experiment station for a period of four years. No fer- 

 tilizer was applied to the plats the fourth year, owing to the exces- 

 sive vine growth produced during the previous three years. Muriate 

 of potash has been held by some to afford protection from certain 

 insects owing to its repellent action, and four of the plats to which 

 this material was applied, along with other ingredients, were kept 

 under observation by the writer. The data in Table VI 1 show the 

 fertilizers and the amounts applied on four plats, consisting of one- 

 twentieth of an acre each. 



Table VI.- 



-Experimenl with fertilizers as repellents against the cranberry 

 girdler, Whitesbog, N. J., 1915. 



Plat No. 



Fertilizer tested. 



Plat No. 



Fertilizer tested. 



11 



10 pounds muriate of potash, 25 



pounds acid phosphate, 10 pounds 



ammonium sulphate. 

 10 pounds muriate of potash, 25 



pounds acid phosphate, 20 pounds 



dried blood. 



29 



10 pounds muriate of potash, 15 



pounds phosphate rock, 10 pounds 



ammonium sulphate. 

 10 pounds muriate of potash, 15 



pounds steamed bone, 10 pounds 



ammonium sulphate. 



13 



31 







1 Extracted from Proceedings of the 46th Annual Meeting of the American Cran- 

 berry Growers' Association. 



