42 



ant. Somewhere in the vast maize fields to the west of us, 

 the species found that it could both breed and subsist in 

 these fields of corn, and the consequence is that the country 

 to the east of where the adaptation took place, is being 

 flooded with a corn feeding race, not differing from the 

 original as yet, but is pushing its way from field to field, 

 and probably thousands if, indeed, not millions of individ- 

 uals now occur where few if any occurred before. Over the 

 area of reclaimed swamp lands, once the home of Dragon 

 Flies, aquatic beetles and other swamp infesting insects, now 

 totally exterminated there, this species may be said to occur 

 in myriads, at the present time. 7 hyn'dopteryx ephcmerce- 

 formis Steph., is without much doubt a Southern form, as 

 are its near relatives the world over, and has probably en- 

 tered Ohio from the south, at no very remote period, ap- 

 pearing in the extreme southwestern part of the state, and 

 slowly working its way northward. Of its former occur- 

 ence, I have but a statement of Mr. R. H. Warder, superin- 

 tendent of Public Parks for Cincinnati, Ohio, that in a copy 

 of "Harris Insects," the following marginal notes, written by 

 his father, the late Dr. John Warder, appear: "December 

 26, 1864, 53 cases on Cedar tree, of these 32 had eggs, 

 about 61 per cent," and "October 27, 1882, many Cedar 

 trees on street. Walnut Hills, with their tops com- 

 pletely stripped by this pest." It now occurs abundantly 

 for about 60 miles northward, then rather sparsely for an- 

 other 60 miles, and probably, rarely within 25 miles of 

 Toledo, on Lake Erie. The Harlequin Cabbage Bug, 

 Miirgantia histrionica Hahn., has, within the last few years, 

 passed over almost the entire length of the state, from north 

 to south, and will probably finish its march to the shores of 

 Lake Erie another season, if, indeed, it has not already done 

 so. Thet^e two latter spt^cies have spread over the state 

 without having to materially change their food habits, or, 

 in fact, adapt themselves to any but climatic differences be- 

 tween their southern home and their present habitat in Ohio. 



