80 



Mr. Schwarz has remarked that the galleries of this species, which 

 he describes and figures, are indistinguishable from those of our com- 

 mon X. dispar, which occurred in the same shoots. The galleries that 

 I have seen in other woods differ considerably, but as the general design 

 is under normal conditions somewhat similar it will be unnecessary to 

 describe them here.— [F. H. Chittenden. 



THE HARLEQUIN CABBAGE BUG ON ASPARAGUS. 



A striking instance of how a plant never before known as furnishing 

 sustenance for a particular species of insect may be attacked by this 

 insect when its appropriate and favored food supply becomes exhausted 

 was recently observed in the case of the harlequin cabbage bug, 

 Murgantia histrionica Hahn. 



September 28, 1896, an asparagus bed at Marshall Hall, Md., was 

 found to be full of these bugs. Hundreds of specimens, naturally 

 mostly mature at this time, but including a small proportion in the pre- 

 paratory stages, were seen gathered in large groups on every main 

 stem of the plants, and so thickly grouped in places that they could 

 easily be seen for 20 yards or more. Thus huddled together, each indi- 

 vidual with its haustellum sunk into the succulent stem, they looked 

 like gigantic black and yellow plant-lice. 



The cause of this unusual visitation was at once apparent. Three or 

 four large beds of cabbage, all completely ruined by these insects had 

 been observed in this same garden on previous occasions, but the dam- 

 aged plants had been removed aud such bugs as had escaped had found 

 their way to the asparagus bed, where they had seemingly made them- 

 selves quite at home. It was noticeable that the asparagus was pre- 

 ferred to all other plants. Only one other crop had attracted them, and 

 this of little importance, the sunflowers, grown for indoor decoration. 

 Beans, beets, and grapes had entirely escaped injury. 



In July of a previous year the writer noticed large numbers of this 

 species in different stages feeding on the common ragweed, Ambrosia 

 trifida. About ten days later all had disappeared. No crucifer on 

 which they might have bred was present in this neighborhood except 

 the shepherd's purse (Capsella barsapastoris), a few stunted, withered 

 plants being found among the ragweeds. They were competely defoli- 

 ated, the leaves having withered, dried, and dropped off, and it is there- 

 fore apparent that the harlequin bugs had originally fed upon this plant 

 until they had completely exhausted its juices and had then been 

 obliged to change their food in order to complete their transformations. 

 The adults found at this time were all newly bred individuals. 



The principal damage wrought by this insect, as is well known, is to 

 plants of the botanical family Cruciferre, and especially to cabbage, 

 radishes, turnips, and kale. As another instance of unusual injury 

 by this species may be mentioned the statement of Dr. J. A. Lintner 

 in his first New York report (p. 265). He relates on the authority of a 



