ANNUAL REPORT, 1936 39 



was continued. California Insectaries, Inc., Glendale, California, donated 

 100,000 of the dark form for this. These parasites had been bred from indi- 

 viduals reared from fruit worm eggs on cranberries collected on bogs in Ware- 

 ham, Mass., in 1935. They were all put out on a bog near East Wareham that 

 is much infested with fruit worms nearly every year. As continual showery 

 weather greatly interfered with the proper handling of the parasites and 

 with their activity, it is perhaps not surprising that no positive results were 

 obtained with them. 



Kerosene and Pyrethrum Extract. A satisfactory machine for applying 

 this mixture as a fog or vapor was built and used rather extensively on experi- 

 mental plots. The mixture was used in different proportions and amounts up 

 to the limit of any possible economic advantage. It failed to kill cranberry 

 weevil beetles (Anthonomus) and black-headed fireworms (Rhopobota) to any 

 considerable extent. The best kill of the blunt-nosed leafhopper (Ophiola) 

 was 80 percent. There is little reason to expect anything of value from further 

 work along this line, for pyrethrum dust is more easily applied and more 

 effective. 



Prevalence of Bog Pests. Notes on the relative general abundance of pests 

 on Cape Cod bogs in 1936 follow: 



1. Black-headed fireworm (Rhopobota) rather less plentiful than usual, much 

 less than in 1935. 



2. Fruit worm (Mineola) rather destructive but somewhat less so than in 

 1935. 



3. Weevils (Anthonomus) and flea-beetles (Systena) more prevalent than 

 usual. 



4. Fire beetle (Cryptocephalus) — more widely abundant than ever before. 

 (See above). 



5. Brown cranberry spanworm (Ematurgia) somewhat more plentiful than 

 normal. 



6. Gypsy moth more destructive in Plymouth county than for many years. 



Gold Storage of Cranberries. (C. I. Gunness, H. J. Franklin, and C. R. 

 Fellers.) A study of home cold storage of cranberries as compared with the 

 storages commonly used has been contemplated a long time. The Department 

 of Agricultural Engineering, the Department of Horticultural Manufactures 

 and the Cranberry Station cooperated during the fall in beginning this neg- 

 lected investigation. While the work has not gone far enough at the time this 

 is written to call for a detailed report, it may be said that positive results 

 already obtained seem to very amply justify the venture. 



Control of Cranberry Bog Weeds. (Wm. H. Sawyer.) Twenty-three 

 different chemicals, alone and in combination, were tested as controls for bog 

 weeds during the season of 1986, 381 plots being treated. Kerosene, sodium 

 arsenate, sodium arsenite, sodium chloride, sodium nitrate, ammonium sulfate, 

 iron sulfate, and calcium chloride were found useful against one kind of weed 

 or another. Of these, kerosene, sodium arsenite, and iron sulfate proved to be 

 the most generally useful. The discovery that kerosene is effective against 

 such difficult weeds as brambles, loosestrife, horsetail, and scouring rush was 

 especially gratifying. The experiments showed that kerosene kills weeds best 

 and harms cranberry vines least when used late in the spring, when the weeds 

 are only partly grown and the vines are still nearly dormant. 



With the generous help of the United Cape Cod Cranberry Co., excellent 

 photographs and colored film strips of some 60 species of cranberry bog weeds 

 were made for extension work. 



