A Infestations rarely affect a significant proportion of the crop. In fact, when the fruit-set is heavy, the thinning effect of the sawfly can be helpful. The surviving apples grow bigger and there is less chance of branches breaking. Most mature fruit with surface-scarring will be otherwise undamaged and remain good to eat. Such fruit can be stored, provided the scar is well-healed. This damage can be more common in certain years and places, so could need control.