Abstract: A three-years study was carried out on egg development by several Sardinianpopulations of green oak leaf roller moth. In Spring 2005 coincidence between budburst and egghatching was analyzed in two mixed oak stands of Quercus pubescens and the evergreen oaksQ. ilex and Q. suber. In each stand the time of budburst was the same for the different oakspecies and egg hatching did not differ in the Tortrix viridana populations associated with eachoak. During 2005/06 and 2006/07, trends of diapause completion and egg hatching of thirteenT. viridana populations collected in some Sardinian forestry districts and associated withQ. pubescens, Q. suber, or Q. ilex were compared in two semi-field trials. In both years T.viridana populations showed differences in cold requirement for diapause completion anddisplayed non synchronous egg hatching.