352 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



FIG. 253. Cabbage maggot, side 

 view, enlarged, hair line repre- 

 sents natural size; a, view of 

 caudal segment; b, outline of 

 spiracle back of head greatly 

 enlarged. (After Slingerland.) 



hill up the earth around the young plants when set, and as soon as 

 eggs are laid, pull the soil containing the eggs away from the plant 

 into the middle of the row, where they or the maggots hatching 

 from them will be killed by the heat. This involves considerable 



hand work, but where carefully 

 and intelligently followed is one 

 of the surest means of control. 



Preventives. Where late cab- 

 bage is grown the plants often 

 become infested in the seed- 

 bed. To avoid this the seed- 

 beds should be covered with 

 cheesecloth. The sides of the 

 frame are made of 12-inch boards, 

 across which wires are stretched 

 to prevent sagging of the cloth, 



as the whole must be fly-tight. The cover should be removed 

 a week or ten days before transplanting, so that the plants may 

 harden. If eggs are observed in the seed-bed during this time, 

 transplant at once. 



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 recent '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 effective. The cards 

 are made in a hexagonal shape, w r ith a slit extending from one 

 corner 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. 255, 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 



