12 BULLETIN 1476. U. S. DEPARTMENT OF AGRICULTURE 
area during 1920. The scouting during 1921 and 1922. however. 
disclosed that a sparse but extensive infestation had occurred in all 
the Pennsylvania towns bordering Lake Erie and adjacent thereto. 
During the summer of 1921 the insect was discovered (May 3. 
1921 1 by scouts of the Federal Bureau of Entomology on the farm 
of Peter Sontz, East Point Eoad. Middle Bass Island. Ohio, in 
Lake Erie. This island is located about 7 miles from the Ohio 
shore. Subsequent scouting during the summer of 1921 revealed 
-parse infestations in most of the townships bordering Lake Erie 
in Ohio and Michigan, and also on the islands in the western end 
of the lake. The borers were more numerous on the islands at this 
time than on the mainland. 
At the close of 1924 P. rmbUaUs was known to be present in 
practically all of the territory along the American shore of Lake 
Erie and extending a short distance inland. (See map. fig. 1.) This 
area includes LS12 square miles in western Xew York: 1.999 square 
miles in northwestern Pennsylvania : 6.591 square miles in northern 
Ohio: and 2.S2^ square miles in southeastern Michigan, a total of 
16.230 square miles in the Lake Erie section. The presence of the 
European corn borer in Pennsylvania. Ohio, and Michigan establishes 
the pest within a short distance of the large and extremely important 
corn-growing areas of the Middle West and also provides a possible 
means of natural dispersion southward because of the presence of the 
insect in the territory drained by the headwaters of the Ohio River. 
DISCOVERY AND DISTRIBUTION" IN" OTHER AREAS 
During the late summer of 1923 a small area of infestation was 
discovered in the Bay Ridge section of Brooklyn. X. Y.. by scouts 
of the Federal Bureau of Entomology. Limited infestations were 
also found during 1924 on the northeastern side of Staten Island. 
X. Y.. just across the channel from the Brooklyn area, and at Little 
Xeck. Long Island. Many of the larvae found in this region were 
inhabiting weeds, and evidences were also present that the insect 
had undergone two generations in this area during 1923 and 1921. 
It is believed that this infestation is of great importance since rather 
extensive >weet corn growing areas are present on Long Island and 
in the near-by districts of Xew Jersey and Connecticut. The situa- 
tion may become especially serious if two generations should continue 
to develop each year in this area. 
A .-ingle specimen of P. nubUalis pupa was discovered during 
July. 1923. in Nelson Township. Madison County. X. Y.. by AY. L. 
Miles, a former employee of the Bureau of Entomology. This area 
is located about 50 miles west of the main eastern Xew York area. 
A few specimens of the larvae were found later in a near-by field 
by a scout of the Federal Bureau of Entomology. Only two infested 
fields were found in this area. 
Extensive scouting operations have been maintained during the 
period from 1921 to 1924 in the territory surrounding and adjacent 
to the infested areas of Xew England. Xew York. Pennsylvania. 
Ohio, and Michigan, as well as along the main lines of travel, river 
valley-, water routes, the vicinity of broom factories, and other 
susceptible localities in those States. Scouting operations have also 
included field examinations in susceptible localities in the territory 
