l62 



AN ECONOMIC ENTOMOLOGY. 



that are predaceous and others that are plant-feeders, and, as in 

 the preceding case, it is difficult to say always whether the 

 species are beneficial or injurious. They will all stand watching, 

 at any rate, but, fortunately, not many of them occur in great 

 numbers. Perhaps the most marked exception is the ' ' harlequin 

 cabbage-bug," Murgantia histrionica. This is one of the most 

 serious pests to cabbage in the Southern States, being found in 



small numbers on Long 

 Island, in the southern part 

 of New Jersey, and then 

 increasing rapidly in num- 

 ber and destructiveness 

 throughout the South and 

 Southwest. These also win- 

 ter in the adult stage, and 

 egg-laying begins quite 

 early in the spring. They 

 are said to pass through all 

 their stages in two weeks, 

 and it can be readily seen 

 that there is room for a 

 number of generations in 

 the course of the season. Practical experiments seem to prove 

 that fighting the adults early in spring is most effective. Mus- 

 tard seems to be their favorite food-plant, and it is recommended 

 to plant rows of mustard between the cabbage rows for the pur- 

 pose of attracting the old bugs. They can be sprayed there 

 with pure kerosene, which kills them readily, and if it also kills 

 the mustard, no great harm is done ; or, they can be collected in 

 pans in the morning, before they have become active, and in this 

 way they will be sufficiently reduced in number to prevent them 

 from becoming troublesome later on. Of course this is another 

 of the remedies that depends for its greatest success upon com- 

 bined action. It has also been recommended that the hibernating 

 bugs be trapped in early spring under turnip or cabbage leaves, 

 preserved for that purpose during the winter. 



The allied family Cydnidce is interesting, having the legs formed 

 for digging, though otherwise resembling the preceding. Their 

 food habits are not well known ; but none of them are mjunous. 



Harlequin cabbage-bug, 

 ica. — a, b, larva and pupa ; 



Miiyganlia hiilnon- 

 c, d, e, eggs, natural 



size and enlarged, from side and top \f,g, adult. 



