October, ’ 24 ] 
BARBER: EUROPEAN CORN BORER MIGRATION 
587 
willow trees. Of the total number of larvae (504) found in these traps 
over the whole period of spring observation, 414 were taken from traps 
placed between the piles of corn stalks and the row of trees. For some 
unknown reason in this instance as well as in the observations made in 
the fall, it seemed that the migration of larvae toward the northeast 
was much greater than in other directions. However toward that direc¬ 
tion there was a considerable accumulation of fallen leaves and other 
places suitable for hiding, including a few weeds. These remarks apply 
only to larvae that left the cultivated area. Those moving about in the 
cultivated area during the fall seemed to move toward fresh food as a 
usual thing. 
Within piled up corn stalks there is also an interesting movement of 
larvae, those in the centre of the pile where the stalks remain wet, 
deserting such stalks and moving to the outer dry stalks where con¬ 
ditions for pupation and emergence are much more favorable and where 
the direct benefit of the sun is felt much sooner than would be the case in 
the centre of such piles. On May 12, 1921 an examination was made of 
such a pile of corn stalks to obtain information on this point. In 46 
stalks partly wet and partly dry—stalks that extended from the centre of 
the pile to the outside—there were found: 
Wet portion Dry portion 
Live larvae 3 173 
Dead larvae 6 16 
Pupae 0 2 
In 50 dry stalks from the outside of the pile there were found: Live 
larvae, 301; Dead larvae, 26; Pupae, 46. 
In 50 wet stalks from the centre of the pile there were found: Live 
larvae, 2; Dead larvae, 4. 
In the above instance stalks were on an average equally infested in the 
fall and larvae remained distributed through the whole pile until it be¬ 
came warm enough for them to become active in the spring. 
This movement of larvae in the spring is different from the fall migra¬ 
tion in that in the spring the larvae apparently seek only favorable places 
in which to transform while in the fall they seek not only more likely 
localities in which to spend the winter but also in many cases fresh food 
to enable them to complete growth. 
We have previously stated that on warm nights of late summer and 
early fall migrating larvae are to be found very active while such ac¬ 
tivity ceases with the coming of day when the larvae seek shelter during 
the hours of daylight. In fact larvae outside of their burrows are very in- 
