THE ROUNDHEADED APPLE-TREE BORER. 15 
work should be done not later than the Ist of September; farther 
south it may be done several weeks or a month earlier, and north of 
the States mentioned the time will be correspondingly later. A 
second examination should be given the trees the following spring to 
secure borers from belated eggs or those that may have been over- 
looked at the fall worming. , 
The fact that the adult female does not habitually wander far in 
depositing her eggs (see fig. 3) is greatly to the advantage of the or- 
chardist who depends on worming to save his trees. When once his 
Fic. 16.—Twig and leaf of apple gnawed by adult round- 
headed apple-tree borer. (Original.) 
orchard and all surrounding host trees are cleared of the borers he 
is likely thereafter to be troubled very little by new infestations so 
long as adults are kept from developing within the area. He should 
continue his examinations of the trees every year, however, to de- 
tect in time any fresh outbreaks arising from eggs deposited by 
adults that may occasionally fly into the orchard from a distance. 
Where this method is used all worthless trees in which the borers 
can breed, growing within a few hundred feet of the orchard, should 
