316 ENTOMOLOGY 



into northeastern Ohio, as did also the asparagus beetle (Crioceris as- 

 paragi), the clover leaf weevil (Phytonomus punctatus), the clover root 

 borer (Hylastes obscurus) and other species. In short, as Webster has 

 pointed out, New York offers a natural gateway through which species 

 introduced from Europe spread westward, passing either to the north 

 or to the south of Lake Erie. 



Inland Distribution. Pieris rapce, the spread of which in North 

 America has been thoroughly traced by Scudder, reached northern New 

 York in 1868 (as above), but appears to have been independently intro- 

 duced into New Jersey in 1868, whence it reached eastern New York 

 again in 1870; it was seen in northeastern Ohio in 1873, Chicago 1875, 

 Iowa 1878, Minnesota 1880, Colorado 1886, and has extended as far 

 south as northern Florida, but is apparently unable to make its way 

 down into the peninsula. 



Crioceris asparagi, another native of Europe, became conspicuous 

 in Long Island in 1856, spread southward to Virginia and westward to 

 Ohio, where it was taken in 1886; it occurs now in Illinois. This insect, 

 as Howard observes, flies readily, and may be introduced commercially 

 in the egg or larval stage on bunches of asparagus. 



Cryptorhynchus lapathi, a beetle destructive to willows and poplars, 

 and common in Europe, Siberia and Japan, was found in New Jersey in 

 1882 and in New York in 1896, though known for many years previously 

 in Massachusetts. It became noticeable in Ohio in 1901, and is steadily 

 extending its ravages, being reported recently from Minnesota. 



From Colorado the well-known potato beetle (Leptinotarsa decem- 

 lineatd) has worked eastward since 1840, reaching the Atlantic coast 

 within twenty years, and has even made its way several times into Great 

 Britain, only to be stamped out with commendable energy. The box- 

 elder bug (Leptocoris trivittatus) is similarly working eastward, having 

 now reached Indiana. The Rocky Mountain locust periodically mi- 

 grates eastward, but meets a check in the moist valley of the Mississippi, 

 as has been said. 



The chinch bug (Blissus leucopterus), the distribution of which has 

 been traced by Webster, has spread from Central America and Mexico 

 northward along the Gulf coast into the United States, following three 

 paths: (i) Along the Atlantic coast to Cape Breton; (2) along the Mis- 

 sissippi valley and northward into Manitoba; (3) along the western 

 coast of Central America and Mexico into California and other Western 

 states. Everywhere this insect has found wild grasses upon which to 

 feed, but has readily forsaken these for cultivated grasses upon occasion. 



