270 The Spraying of Plants. 



ward along the Atlantic coast, and is showing itself to be per- 

 haps the worst enemy of the cabbage grower. The adult bug 

 is nearly half an inch in length. It is brightly marked with 

 black and orange colors, and for this reason has received its 

 popular name. The mature insect hibernates during the 

 winter ; in early spring, as soon as the cruciferous plants upon 

 which it feeds make their appearance, the eggs are laid, com- 

 monly on the under side of the leaves, and closely cemented in 

 a double row containing about a dozen eggs. These hatch 

 within a week, and the young pests then begin to suck the sap 

 from the leaves. So active are their operations in this direction 

 that it is said a young cabbage plant will succumb in one day 

 if attacked by half a dozen of the insects. The bugs are very 

 shy, and if disturbed they try to hide. They mature in about 

 twelve days from the time the egg is hatched, and this allows 

 of the appearance of several broods each year. 



Treatment. For several reasons this insect is very difficult to 

 control. It cannot be destroyed by poisons which are taken in- 

 ternally, and on account of its active habits it is difficult to 

 reach with external applications; again, the rapidity with which 

 it can multiply renders very thorough work necessary from the 

 start, else their number will soon increase to an extent sufficient 

 to ruin the cabbage plants. Hand picking has been recom- 

 mended, but it is of doubtful value when large areas are af- 

 fected. One habit of the pest may prove of considerable service 

 in its destruction. During the nights of spring and autumn, the 

 adult insects collect under chips, boards, etc., and under small 

 piles of leaves or some similar materials which afford them good 

 hiding-places. If these are removed or burned in the morning 

 after the insects have collected under them, large numbers may 

 be disposed of. This practice is particularly valuable if the 

 brood which hibernates during the winter can be so destroyed, 

 since this largely reduces the abundance of the future genera- 

 tions. Another method of destroying this brood and of saving 

 the cabbage plants has been suggested by Weed. The harlequin 

 cabbage-bug is very fond of mustard, and if the latter is sown 

 between the rows of cabbages almost all the insects will collect 

 upon the mustard. This should then be sprayed with pure 

 kerosene, and thus the hibernating bugs can practically all be 

 destroyed. 



