| Abstract: | Willow species and hybrids growing in the Stott willow collection at Ness, UK, differed markedly in their susceptibility to leaf damage by insects, predominantly chrysomelid beetles, with the rank order of susceptibility remaining relatively constant over 2 years. Some species displayed a wide range of variation in susceptibility amongst clones; others very little. The range of susceptibilities of hybrids tended to mirror those of the parent species, with the hybrid usually sustaining leaf damage levels intermediate between those of the parents. Leaf damage in most species was higher on the lower leaf surface up to mid-season, beyond which leaf perforation damage became prevalent. Damage levels did not appear related to leaf toughness. Apparent levels of leaf damage were lower in October versus July/August samples across nearly all species. Heavy leaf damage in one year did not appear to induce the production of leaves that were more resistant to insect attack in the following year. |
