The Bulletin 
109 
edge of a rice field on March 29, 1911. On that date one beetle was 
found in a clump of grass, where it w T as moving about; hence it was 
not exactly in hibernation. Sticks, stones, logs, dead grass and weeds, 
brush, and, in fact, every movable thing in the field, have been over¬ 
turned in the search for beetles in hibernating quarters other than 
cornstalks.” 
Just what becomes of the early maturing adults has never been 
determined. During mid-season the adults seem to emerge from the 
pupal cells in from five to seven days after transformation; later in 
the season this time seems to be gradually extended, and the late beetles 
remain in the pupal cells all winter. The writer believes that the 
early maturing beetles leave the cornfield late in the season, especially 
if the corn has been planted early, arid migrate to later corn or to 
adjacent patches of cyperus grass, where they undoubtedly go into 
hibernation anywhere in the field a few inches below the surface. USTo 
beetles have been found save those that were still in pupal cells, in 
spite of the fact that we have sifted the top five or six inches of soil in 
many different parts of various cornfields that had been badly infested 
with bill bugs the previous season. Any one, however, who has had 
any experience with bill bugs in the field will appreciate the difficulties 
involved in attempting to locate bill bugs by sifting, and it is not at 
all remarkable that we were unable to locate them. 
BEETLES FROM EMERGENCE TO HIBERNATION 
Just Avhere the early maturing adults spend their time from the time 
when they emerge from the pupal cells till they go into hibernation 
is still in part an unsolved problem. Part of the adults, evidently 
late maturing ones, remain in the pupal cells over winter; and part 
of the early maturing adults emerge from their pupal cells and feed in 
the same fields with their parents. Whether these young beetles lay 
any eggs the first season or not is discussed in another connection. 
In fields of early or medium early planted corn the corn reached 
maturity in early September, and in such fields all the adult bill bugs 
have practically disappeared by late August. In later planted corn, 
especially in extremely late corn, the stalks may stay green and tender 
until after heavy frost, and the adults continue in such fields until 
late October, at least, evidently not seeking hibernation quarters until 
early November. In most cases, however, no such late corn is avail¬ 
able, and it therefore becomes a problem to determine just where the 
adult bill bugs live from late August to early November. In the hope 
that we would be able to solve this problem, something in the neigh¬ 
borhood of five hundred pairs of adult corn bill bugs were marked in 
various ways in early August, 1912. 
The adults marked in 1912 had a spot of bright water color painted 
either on the thorax or the elytra, as this method of marking had been 
