70 
The fact that in fields newly set in the spring, young plants root-. 
ing from runners the same season are sometimes found infested by 
borers in the fall, can only be accounted for on the supposition that. 
some of the beetles which have hibernated, are conveyed to the new 
field on the plants or in the earth about their roots. It will per- 
haps be objected that these new fields may be infested from a dis- 
tance, notwithstanding the well-known sluggishness of the adult, by 
beetles which take wing. This hypothesis is at once disposed of, 
however, by a fact curiously simple and of easy observation, but 
which has hitherto escaped attention, and which at the same time: 
accounts for the slow spread of the pest, viz: that the beetle is 
practically wingless, and incapable of flight. 
There can scarcely be a shadow of doubt remaining that this 
species is single-brooded, since it has now been traced throughout. 
the entire period from the first of August to the first of May, oc- 
curring in the beetle stage during these nine months, and leaving but a. 
period of three months for the hatching and development of the 
earliest larve to the adult condition. 
