pests and diseases
...that cultivated Christmas trees are susceptible to such pests and diseases as the Balsam woolly adelgid and sudden oak death?
...that cultivated <a href="./Christmas_tree" id="mwCYg" rel="mw:WikiLink" title="Christmas tree">Christmas trees</a> are susceptible to such <b id="mwCYk"><a href="./Christmas_tree_pests_and_weeds" id="mwCYo" rel="mw:WikiLink" title="Christmas tree pests and weeds">pests and diseases</a></b> as the <a href="./Balsam_woolly_adelgid" id="mwCYs" rel="mw:WikiLink" title="Balsam woolly adelgid">Balsam woolly adelgid</a> and <a class="mw-redirect" href="./Sudden_oak_death" id="mwCYw" rel="mw:WikiLink" title="Sudden oak death">sudden oak death</a>?