34 DISTRIBUTION" AND DISPERSION OF LEPTINOTARSA. 



The feature of most interest in this year is the rapid spread over Ontario 

 and the advance down the St. Lawrence River Valley. Of interest also is 

 the rapid pushing out of projections along the natural highways which 

 penetrate the Appalachian highland and afford easy passages to the Atlantic 

 coast area. 



1873. In this year, over most of the area in which the beetle was now a 

 resident, it was found in only moderate numbers, although it was abundant 

 in some counties and did more or less injury to crops. In Minnesota, Wis- 

 consin, Michigan, Iowa, Illinois, Indiana, and western Ohio almost no 

 damage was done, and consequently it passed almost unnoticed. In north- 

 eastern Ohio it was a pest, one newspaper describing their abundance in the 

 following words : ' ' Clouds of Colorado potato-beetles .... The scene 

 suggested to Bible readers locusts in ancient days." Riley remarks that 

 he has good authority for the statement that at best only a few dozen could 

 be seen at one time by a single person. In this year the insect covered the 

 whole Province of Ontario (C. J. S. Bethune), fifty-nine agricultural societies 

 reporting its presence, but in most instances only a small amount of damage 

 was done. 



During the two years following the advance introduction into Lancaster 

 County, Pennsylvania, which was first noticed in 1872, the beetle advanced 

 eastward and southward with great rapidity. It spread east into Salem 

 County, New Jersey, and into Caroline, Dorchester, Frederick, Queen Anne, 

 Cecil, Baltimore, and Washington Counties, Maryland (Glover). It was 

 found in the District of Columbia, where living specimens were taken to the 

 United States Department of Agriculture for identification. It was also 

 found in Prince William and Page Counties, Virginia, and in Butler, Clear- 

 field, Franklin, Northampton, Perry, Bedford, Huntingdon, Cambria, 

 Juniata, Armstrong, and Indiana Counties, Pennsylvania (Glover). In 

 New York it was reported from Erie County, and in West Virginia from 

 Monroe, Preston, Hardy, Jefferson, Marion, Brooke, Tyler, Fayette, and 

 Pleasants Counties (ibid.). No specimens were seen from these West Vir- 

 ginia localities. It was also recorded from Nicholas, Anderson, Clarke, 

 Lexington, and Fayette Counties, in Kentucky, and from Fentress County, 

 in Tennessee. 



The boundary of the invasion in Minnesota and Wisconsin does not change 

 in this year ; in Michigan it has moved northward, but is parallel with that 

 of the preceding year. From Michigan the line crosses Lake Huron to 

 Georgian Bay, passes along the northern border of the Province of Ontario 

 and the St. Lawrence River Valley to near Montreal, where it turns south- 

 ward in a tongue along the Lake Champlain Valley, then westward along 

 the southern side of the St. Lawrence Valley to western New York. In 

 New York, Pennsylvania, and West Virginia the tongue-like projections 



