214 AN INTRODUCTION TO ENTOMOLOGY. 



their habits; some are injurious to vegetation; others are preda- 

 ceous ; while some species feed indifferently upon animal or vege- 

 table matter. 



The Harlequin Cabbage-bug, Murgantia histronica. — Among the 

 species of the Pentatomidae that feed upon cultivated plants, the 

 Harlequin Cabbage-bug, or " Calico-back" as it is called in some 

 sections, is the most important pest. This is a very common insect 

 in the Southern States. It occurs from New Jersey southward and 

 westward. I have specimens from Colorado, and Arizona. It feeds 

 upon cabbage, radishes, turnips, and other Curciferous plants ; it is also 

 found sometimes on plants not closely related to cabbage. The 

 adult bug measures about 10 mm. (0.4 in.) in length. It is polished 

 blue black, banded striped, and margined above with yellow, orange, 

 or red ; on the venter it has seven lines of yellow and orange spots ; 

 and the head has generally two white spots on the front. The relative 

 proportions of the black and the light colors vary greatly indifferent 

 specimens. This bug winters in the adult state ; in early spring it 

 emerges and lays its eggs on the young plants. The eggs are usually 

 attached to the lower surface of the leaves in two parallel rows of 

 about six each. The young larva is of a uniform pale-green color, 

 marked with black ; with the successive moults the various orange 

 markings appear. In the immature stages the antennae are only four- 

 jointed. This insect develops very rapidly ; the eggs hatch on the 

 third day after they are laid ; and it is said that the bugs will pass 

 through all of their moults and be ready for reproduction in two 

 weeks. There is a series of generation extending through the en- 

 tire summer. This is an exceedingly difficult species to contend 

 against. Much can be done by trapping the bugs that have 

 hibernated by placing turnip or cabbage leaves in the garden in early 

 spring. 



As if to atone for the destruction caused by their relative, the 

 Harlequin Cabbage-bug, there are many members of this family 

 which aid the agriculturist, by destroying noxious insects. I can- 

 not, without going into details inappropriate here, point out so that 

 they could be recognized the predaceous members of this family. 

 And it would hardly be worth while. It is only in case of excep- 

 tional species, like that just described, that these insects occur in suf- 

 ficient numbers to invite the attention of the agriculturist. They are 

 usually found wandering singly over the plants which they attack or 

 upon which they search for their prey. 



The species of the genus Podisus have been reported more often 



