INJURIOUS INSECTS. IO7 



food plants and often upon the plants themselves. 

 In a short time these hatch into maggots, which at 

 once attack the roots. The maggots become fully 

 grown in three or four weeks, when they leave 

 the roots, and transform to pupae. The adults 

 emerge from the puparia usually in from fifteen 

 to twenty days. 



The best (or one of the best) method of pre- 

 venting the work of the cabbage maggot, or to 

 protect from the maggot is to plant cabbages and 

 allied vegetables in a new place each year, as far 

 removed from the ground on which they were raised 

 the preceding year as possible. The best insecticide 

 for this pest is an emulsion of carbolic acid, 

 employed to the roots of the plants. The best 

 mechanical device for preventing their work is 

 tarred paper disks placed about the plants. 



THE HARLEQUIN CABBAGE BUG. 



The harlequin cabbage bug, or calico back, is an 

 oval, somewhat flattened black bug, with bright red 

 and yellow markings arranged as seen in Fig. 18, 

 a, b, showing young bugs ; c, d, e, eggs ; f, g, adult, 

 natural size. It lives all the year round in the more 

 southern United States upon cabbage, mustard, 

 radish, and cruciferous plants, puncturing the 

 leaves with its beak, and causing them to wither 

 and dry. 



This insect was originally an inhabitant of 

 Mexico and Central America. It appeared in Texas 

 in 1866, and gradually spread, from year to year, to 

 the north and east. The eggs are about one- 



