-5*+5- 
in \i/estern Now York; portions of the Hudson River Valley in eastern New York; 
Long Island, New York; Centre and Bucks Counties, in Pennsylvania; two counties 
in southern Vermont and one in southwestern New Hampshire; eastern Massachusetts 
and Hampden County, in that State; the States of Connecticut and Rhode Island; 
the central part of New Jersey; southern Delaware; most of the Eastern Shores 
of Maryland and Virginia; Princess Anne County, on the southeastern mainland of 
Virginia. 
The highest infestations per county in 1940 occurred in Nassau County, Long 
Island, N. Y., and Niagara County, N. Y, , which averaged 742.2 and 703*6 borers 
per 100 plants, respectively. Other relatively high populations — 501 to J00 
"borers per 100 plants — were found in Gratiot and Sanilac Counties, Mich.; 
Columbia and Orleans Counties, N. Y,; Fairfield County, Conn.; Burlington County, 
N. J, ; and Accomac and Princess Anne Counties, Va# 
The data, show significant increases in abundance of the European corn 
borer in 1940 from 1939 in comparable surveyed sections of Indiana, Ohio, 
western New York, Long Island, N. Y., New Jersey, Delaware, Maryland, and 
Virginia; significant decreases in Vermont, Massachusetts, Connecticut, and 
Rhode Island; and no significant changes in the levels of population in Wiscon- 
sin, Michigan, Bucks County, Pa., eastern New York, New Hampshire, nor Marine. 
Infestation in the few counties surveyed in southeastern Wisconsin in 1940 was 
light, as in' 1939 > whereas in southeastern Michigan larval populations continued 
at high levels. The increases in abundance of the insect from 1939 to 19^0 in 
the surveyed portions of Indiana and. Ohio brought the populations in these 
States to the highest levels on record, and in the four counties surveyed along 
the southern edge of Lake Ontario, in western New York, the borer reached its 
maximum abundance for tha.t section of the country. Although less abundant 
throughout New England and in eastern New York proper in 1940 than in 1939 > the 
corn borer became much more numerous southward along the Atlantic coast from 
Long Island through New Jersey, Delaware, Maryland, and Virginia. 
Wisconsin and Illinois . — Only a light infestation of the European corn 
borer — 5*3 larvae per 100 plants — was found during a survey in 1940 of 6 counties 
in the southeastern corner of Wisconsin, indicating little change in abundance 
from the average of 3*3 borers per 100 plants noted in the same counties in 
1939* A survey in 1940 of the 5 counties in northeastern Illinois, in which 
the corn borer was first recorded in 1939 1 showed that populations of the insect 
in that section were too- sparse for measurement by the method employed. 
Kentucky . — Four counties along the Ohio River, in northeastern Kentucky, 
on record, as infested by the Europern corn borer, wore surveyed in 1940. No 
infestation was found in 2 of the counties and only a -trace of the insect in 
the other 2. The result was an average of only 0.3 borer per 100 plants for 
the 4 counties as a group, 
Indiana . — The European corn borer in Indiana has steadily increased in 
numbers from 193& 1° 19 40, Within a section of 35 counties in the State, which 
has been intensively surveyed each year, the average number of borers per 100 
plants more than doubled from 14.9 in 193 ^ to 34.1 in 1939 » nnd again increased 
in about the same proportion, from 34.1 in 1939 to 77*4 in 1940. Significant 
