Improved insect performance from host-plant defoliation: winter moth on oak and apple

ABSTRACT. 1. We test the hypothesis that defoliation has short-term and long-term negative effects on performance of winter moth Operophtera brumata L. on two species of food plants: Garry oak ( Quercus garryana Dougl.) and apple ( Malus domesticus L.).
2. Pupal weight (and hence potential fecundity of females) decreased with increased defoliation in the current year on both tree species.
3. Pupal weight increased, however, with increased level of defoliation in the previous year.
4. Increased weight of pupae from larvae which had fed on previously defoliated trees may buffer population decline by increasing fecundity of moths in the next generation.