DISTRIBUTION 381 
are distinctly Central American and West Indian in their 
affinities. Indeed Uhler is inclined to believe that the principal 
portion of the Hemiptera of the United States has been derived 
from the region of Central America and Mexico. 
Eastern.—On the Atlantic coast are many European species 
of insects which have arrived through the agency of man. 
Most of them have not as yet passed the Appalachian moun- 
tain system, but some have worked their way inland. Thus 
the common cabbage butterfly (Pieris rape), first noticed in 
Quebec about 1860, was found in the northern parts of Maine, 
New Hampshire and Vermont five or six years later, was 
established in those states by 1867, entered New York in 1868 
and then Ohio. Aphodius fossor followed much the same 
course from New York into northeastern Ohio, as did also the 
asparagus beetle (Crioceris asparagi), 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.—Picris rape, 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 introduced into New Jersey in 
1868, whence it reached eastern New York again in 1870; it 
was seen in northeastern Ohio in 1873, Chicago 1875, lowa 
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 con- 
spicuous 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 read- 
ily, and may be introduced commercially in the egg or larval 
stage on bunches of asparagus. 
Cryptorhynchus lapathi, a beetle destructive to willows and 
