The Bulletin 
107 
field where the corn bill bug damage had been very serious during the 
summer of 1912, and . did not find a single corn bill bug until I took 
a spade and spaded the stubble out of the ground, taking care to get 
about three inches below the level where the roots would ordinarily 
break if the stubble had been pulled out directly. Then by carefully 
splitting the stalk lengthwise and dividing the soil below the tap-root, 
a bill bug could be found under practically every stalk that showed 
indications of a larval burrow,. This occurred in about 60 per cent 
of the stalks in the same part of the field and in adjacent rows to those 
where we had pulled up over three hundred stalks and had not found a 
single adult. Occasionally one would find the lump of soil sometimes 
at a distance of five or six inches from the tap root. Perhaps more 
beetles occurred in such situations than we actually observed, for in 
the winter, when bill bugs are inactive, they are exceedingly difficult 
to distinguish from lumps of earth. When one was found in such 
situations it was usually due to the fact that the lump of earth adher¬ 
ing to the roots happened to break across the pupal cell, which would 
usually be conspicuous because it was a Cavity with a smooth surface. 
Discovery of the pupal cell usually led to the discovery of the beetle; 
sometimes it was found projecting from the other half of the cell, but 
more often it was found among other little lumps of earth, from which 
it could usually only be distinguished by individual examination. 
Thus it seemis safe to conclude thta the beetle stage is the only one 
that ordinarily passes the winter, for many adults have been discovered 
in hibernation and no other stages have been found. The only apparent 
exception to this statement is the record of a single pupa found by 
Mr. Hyslop, as recorded below; but, as explained elsewhere, the larvae 
that develop from the last eggs laid in corn undoubtedly do not reach 
maturity before early November; hence this record would have to be 
excluded as a hibernating individual. Of the individuals that have 
been found in hibernating quarters, about 90 per cent were in pupal 
cells in the ground below the tap-root and about 2 per cent in the larval 
burrows in the stalks, and a little more than 7 per cent were in pupal 
cells among the roots. 
The peculiar situation of the pupal cells perhaps accounts for the 
fact that others have had difficulty in locating hibernating bill bugs, 
as Mr. Smith’s record will show. 
“The bill bugs hibernate ordinarily in the beetle stage. This state¬ 
ment is made without reservation and is based on many field observa¬ 
tions during the winter of 1909-1910, when careful search on several 
occasions failed to reveal any eggs, larvae, or pupae in the field where 
bill bugs were known to have bred during the previous falls. It has 
proved to be extremely difficult to find any bill bugs in their winter 
quarters, but the total absence of larvae and pupae in the breeding places 
proves that the winter is not passed in either of those stages. 
