INSECTS INJURIOUS TO CABBAGE, ETC. 



319 



The most successful preventive yet used consists of a tarred 

 felt card placed around each plant so as to form a collar, lying 

 upon the surface of the soil and thus preventing the fly from 

 depositing her eggs. These cards were originally devised by 

 Professor W. H. Goff, of Wisconsin, and have been extensively 

 used by large growers in that State for many years, as well as 

 in New York, and experiments in New Jersey and Minnesota 

 have proven them very satisfactory. The cards should be made 

 of one-ply tarred felt, as ordinary tarred paper or building paper 

 curls up and is not as effect- 

 ive. The cards are made in 

 a hexagonal shape, with a 

 slit extending from one cor- 

 ner to the centre, which is 

 slit with a star-shaped cut 

 to accommodate the stem. 

 The cards are cut with a tool 



shown in Fig. 269, which may 



be made by any blacksmith, 



and are cut out in rows as 



illustrated, one cut of the 



tool making a card. The 



cards should be placed 



around the plants when 



they are set. The earth FIG. 268. Cabbage roots destroyed by the 



should be smoothed down cabbage maggot. (After Slingerland.) 



and well firmed by the hand, the card then applied to the 

 plant, and pressed down tight to the ground, so that it fits snugly 

 around the stem and the edges of the slit meet. With a little ex- 

 perience the cards may be applied rapidly, and though involving 

 considerable handwork, the testimony of those who have used 

 them for many years shows that the method is entirely practical 

 and is to be preferred to doubtful remedies. 



A mixture of lime and carbolic acid has recently been used 

 by applying it to the surface of the soil around the plants, 

 so as to form a slight crust, the carbolic acid acting pos- 

 sibly as a repellant. The lime is slaked to a thin cream, and 

 diluted to 3 pints to a gallon of water to which is added a table- 

 spoonful of crude carbolic acid. It is applied liberally to the 



