... the trees and the possibility that the trees will survive Furthermore, we were able to confirm the hypothesis that there is an increase in the density of the predator during the invasion of the ... onwards, coincides with the appearance of the adults and the laying of the pine scale which extends from the end of February / beginning of March to mid-April / end of May, depending on the site The ... forward a hypothesis concerning the behaviour of the laying females According to this hypothesis, after being fertilised in the deep cracks of the trunk, they make their way to the needles via the branches...