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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
Larval Migration Studies 
During the progress of larval migration studies, the exact distance to 
which the larvae are capable of migrating has not yet been determined, 
but sufficient evidence has been accumulated to show that their migra¬ 
tory powers are very pronounced and sufficient to enable them to seek 
adequate shelter at a distance of several feet. Individuals which mi¬ 
grated from various host plants in the Autumn were found to have over¬ 
wintered successfully in dry loose leaves, in fence posts, wooden buildings, 
telegraph poles, under the rough bark of trees and in such woody 
stemmed plants as blackberry, raspberry, sumac, elderberry and grape. 
Individuals which migrated in the Spring were also found in similar 
situations. In all instances the greater part of the migrating individuals 
were able to pupate successfully and emerge as adults. 
This migratory habit of the larvae, together with their ability to sur¬ 
vive in situations affording only a minimum amount of protection, 
renders it necessary to attach considerable importance to larvae which 
leave their host plant when such plants are roughly handled, and larvae 
which are able to reach the soil surface during the course of plowing 
under operations. 
Host Plant Studies 
In the investigations pertaining to the host plants of the corn borer> 
several interesting and important points were noted during the past 
season. 
Along the northern edge of the infested area in New Hampshire, 
where the infestation is exceedingly sparse and only a small amount of 
corn is grown, the corn borer was found to be confined during the early 
season, to such early developing weeds as Polygonum and Rumex. There 
has been a theory advanced that much of the injury to plants other than 
corn, especially in New England, was due to an “overflow” from com. 
While under some circumstances this effect has seemed evident, the fact 
that the borer has been repeatedly found in weeds, under conditions of 
sparse infestation, would seem to indicate the essentially omniverous 
character of the species. In this connection it is worthy of note that 
the borer was found in weeds at Brooklyn, N. Y., even in the presence 
of an exceedingly light infestation. 
Throughout the older and more severely infested area of New England, 
the season of 1923 was characterized by a great reduction of infestation 
and injury to vegetables, flowers, field crops and weeds, a reflection of 
general conditions which will be discussed later. 
In New York, Pennsylvania, Ohio and Michigan, occasional borers 
