New York Agricultural Experiment Station. 413 



lished the results of an experiment that he had conducted on Long 

 Island. He commended this method of protecting cabbage plants, 

 and his recommendations have been copied or abstracted b} r a number 

 of entomologists in this country and Europe who have published 

 on this insect. However, this method has not been widely adopted 

 by growers and until recently only a few entomologists have en- 

 deavored to demonstrate its practicability. Schoyen 12 of Norway 

 gives an account of an unsuccessful test with tar pads in which 

 checks and treated cauliflowers were equally injured. Blair 13 of 

 Canada reports in detail the results of an experiment in which 

 only 15 per ct. of the protected cabbage resulted in fair or vigorous 

 plants. As the experimental plat was little better than the check, 

 he attributes the failure to the possiblity that the tar pads were 

 applied too late. In his report for 1907 Smith 14 says " tarred- 

 paper disks were distinctly effective. Several hundred were used, 

 all told, and ... on only two plants were maggots found 

 later." In a summary of the following seasons' work he again 

 remarks 15 " As a protection to the cauliflower and cabbage plants, 

 the tarred-paper disks proved to be both practical and effective." 

 Washburn l6 describes an experiment in his report for 1907-08 that 

 was decidedly unfavorable to tar pads and states that similar results 

 were secured in 1906. This failure is attributed to the use of tar 

 paper instead of tarred felt for the protective disks. He later 

 secured some tarred felt cards from Smith Brothers of Green Bay, 

 Wisconsin, which were placed about cauliflower seedlings on May 23. 

 Of these plants 77 per ct. of the protected and 67 per ct. of the 

 check plants produced heads. Britton and Walden 17 in a summary 

 of tests covering several years state " these disks have given the 

 best results of any form of treatment." Caesar l8 of Ontario, Canada, 

 gives the results of a test in which 648 tarred disks were used and 

 90.6 per ct. of the protected plants lived as compared with 42.6 per 

 ct. of the checks. He states that the pads were a great success; 

 and that the differences in the treated and untreated lots were greater 

 than the figures would indicate. 



12 Schoyen, W. M. Beretning Skadeinsekter og Plantesygdomme, p. 23. 1896. 



13 Canada Exp. Farms Rept. 1904, p. 362. 

 " N. J. Exp. Sta. Ann. Rept. 1907, p. 439. 



16 N. J. Exp. Sta. Ann. Rept. 1908, p. 357. 

 ■•Minn. Exp. Sta., Bui. 112, p. 202. 1908. 



17 Eighth Rept. State Ent. of Conn., p. 835. 1908. 



18 Ontario (Canada)Agricultural College. 37th Rept. p. 40. 1911. 



