140 ENTOMOLOGICAL NEWS. [May 



some places been devoted to coxti continuously for over a century, 

 but this insect known to be so destructive to this crop is just find- 

 ing its way to that locality. The species may be expected to spi-ead 

 eastward in the centre of the State until it reaches the Muskingum 

 river, when it will likely spread throughout the valley of this 

 stream, where corn is the principal crop and is grown continuously 

 on the same land for a series of years. With any amount of search- 

 ing we have never yet found a single specimen of Diabrotica longt- 

 cornis about Wooster, though the future will doubtless see it 

 abundant in the bottoms of the Killbuck, a small stream with wide 

 bottom lands on either side. 



In Murgantia histrionica we have a different problem of diffu- 

 sion to solve, and whatever influence rivers have had in shaping 

 the li-end of such diffusion, this has been by such as are located in 

 adjoining States, except possibly in a single instance, where the 

 Ohio river may have had something to do with its course of migra- 

 gration for a comparatively short distance. See Map 3. 



As is well known, this species is a native to Central America, the 

 West Indies and probably Mexico. Our first record of its appear- 

 ance in the United States gives its area of distribution as " Louisi- 

 ana and Texas," and extends back to 1864. Since that time it has 

 spread to Long Island, New York, on the Atlantic coast, and inland 

 it is now found in Colorado, Missouri, southern Illinois, extending 

 northward in Indiana to Indianapolis and in Ohio to within twenty 

 miles of Lake Erie. 



It has never been a seriously destructive insect in Illinois, and in 

 Indiana only so along the Ohio river below Louisville, Kentucky, 

 where it first began to attract attention in 1890. When I came from 

 Indiana to Ohio in 1891 there was in the insect collection of the 

 Experiment Station a single specimen, said to have been collected 

 in Warren county a year or so before. Prof. A. D. Hopkins has 

 since informed me that he took a specimen in Wood county. West 

 Virginia, in 1891. Being already interested in the distribution and 

 diffusion of this species I was on the watch for its appearance in 

 greater numbers and in other localities, but was not able to sub- 

 stantiate its occurrence in Warren couLty, or, indeed, find it at all, 

 either in the vicinity of Cincinnati or elsewhere to the westward 

 to the Indiana line, the direction from which I naturally expected 

 it to enter the State. 



In 1895 I was surprised to receive it from a locality nearly 120 

 miles in a direct line east of Cincinnati and up the Ohio river. 

 Within a week after this fii*st report canje a second from a point 

 about eighty miles southeast of Cincinnati and also on the Ohio 

 river. In both instances it was stated that the pest had worked 

 serious i-avages the year before, 1894. Still the species could not be 

 found anywhere about Cincinnati, although the large aci'eage of 

 cabbage, its principal food plant in that vicinity, would imply its 

 appearance there as soon as elsewhere, especially as its appearance 



