February, ’ 20 ] 
MARLATT: EUROPEAN CORN BORER 
77 
square miles and that actually the percentage of infestation of this 
township was very light. Looking at it one way, this record shows 
only one larva to the square mile after a painstaking search! 
The inspection work with respect to the corn borer has been neces¬ 
sarily limited. Time and funds have not been available for intensive 
work such as has been done, for example, in the pink bollworm surveys 
in Texas. As an illustration, Dr. Hunter reports that 209 man days 
were spent on a single cotton field, that is, 1 man 209 days or 209 men 
1 day. On the 209th day a single worm was found. After that 100 
other man days were spent in the same field without finding another 
worm,—that is, intensive search. We have not been able to make 
that sort of intensive search in the case of the corn borer, but undoubt¬ 
edly in a great majority of the towns in Massachusetts and elsewhere 
where the insect has been found it would probably be a very difficult 
matter to recover the insect again. The records indicate, however, 
that the insect is still rare over much of the district that it now invades 
and over which, in large part at least, it has been in existence for a 
considerable number of years. 
In this connection Mr. Worthley states in his letter transmitting 
these tables that “it is rather difficult to give much of an estimate of 
percentage of stalks and ears infested in these different fields. I am 
sure, however, it does not exceed 1 per cent as an average.” The 
tables referred to are submitted herewith. 
The full records of the survey work in the latter half of 1919 in the 
states now known to be infested and in other states is also a matter 
of interest—the survey in the infested states extending very much 
beyond the area actually found infested. Records are not available 
for Connecticut, Indiana, Kentucky, Illinois, and other western states, 
where some work was also done late in the season. 
In New York state the same conditions as to the spread and 
abundance hold true, only the insect is much more rare on account of 
its single broodedness in that state. 
The corn borer situation in New York and in Massachusetts has 
been investigated independently by three or four different bodies of 
experts outside of the working forces of the Bureau of Entomology. 
It was investigated by the Federal Horticultural Board three times, 
twice in August and again about the first of October. The representa¬ 
tives of the board went over the ground very thoroughly, not merely 
going through the special exhibit fields, but stopping at many others. 
A good deal of difference was noted in those selected for the board to 
inspect and those within the district taken at random. Again, a 
body of corn technologists, specialists of the Bureau of Plant Industry 
of the department, went over these areas in New York and Massachu- 
