The Cabbage Root Maggot. • 525 



them in position, and boring an i>^ inch hole in each ; a hoe 

 handle put through the hole in the roll of paper, serves as a 

 roller. The cutting block is made wide enough to work the 

 whole width of the paper by fastening several blocks of hard wood 

 together ; it is then stood on end immediately in front of the 

 roller." This arrangement is shown in figure 15. Where large 

 numbers of the cards are to be cut, some such device would facil- 

 itate the work very much. 



Being very favorably impressed with this preventive method devised by 

 Mr. Goff, we planned to further test it on our experiment plot on Long 

 Island. A diagram and description of this plot is given on page 551. The 

 diagram represents the rows on which we planned to put the cards. They 

 were put on April 19, the day after the plants were set. Mr. Reeve, the 

 owner of the plot, applied the cards quickly and quite well for one with no 

 previous experience. May 21, we examined the plot. It required but a 

 glance over the field from the west end to determine which rows had been 

 treated with the preventives, and especially was this true of those protected 

 by the cards. However, as we glanced along the 4th, an untreated row, and 

 the 5th, ai treated row, it soon became evident that either the cards had 

 ofifered but little protection to the plants in the east half of the latter row, or 

 that we had not followed the plan. For the east half of the 4th row, which 

 should have had but few plants standing, judging from the other untreated 

 rows, showed nearly all the plants in good condition. Further examination 

 showed that we had make a mistake and the cards had been applied to the 

 east half of the 4th row instead. Thus the preventive experiments were 

 planned as in the diagram on page 551 but were applied according to the 

 following diagram : 



North. 



1st row : Tobacco Dust 



2d row : untreated 

 H 3d row : Paper Pads 

 j^ 4th row : untreated 



5th row : Carbolic Acid Emulsion- 



6th row : Paper Pads 



South. 



This mistake only served to bring out more strongly the effectiveness of 

 the cards. 



When the examination was made (May 21), the maggots had dine their 

 worst, and scarcely 50 plants rcmaine 1 standing in the untreated rows, while 

 less than 50 had succumbed in either of the two rows protected by the cards. 

 We found a few maggots on some apparently healthy plants that had the 

 cards. Thus the cards had not been a complete success, but they had saved 

 more than we had expected from the conrlitions under which they were 

 applied. The pest appeared in such mumbers as to severely test any method 



Paper Pads. 



untreated. 



Carbolic Acid Emulsion. ^ 



Paper Pads. {§ 



untreated. 



Tobacco Dust. 



