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-2- <br /> MISCELLANEOUS TREE DISEASE AND INSECT PROBLEMS <br /> A late but substantial hatch of cankerworms and loopers dealt <br /> damage to trees for the fourth consecutive spring . This year , <br /> however , an acute preference change to maples caught many by <br /> surprise . Previously preferred tree species ( cherry, flowering <br /> crabs , lindens , and ash) were sprayed in all City parks with Bt <br /> ( thuricide) , an organic bacteriacide toxic only to leaf chewing <br /> worms. While control on the above-mentioned species was <br /> successful , the newly planted maples at City Hall and Silver View <br /> Parks were unprotected . The result of the following defoliation <br /> will be the eventual failing of 5-8 sugar and red maples. <br /> Two other severe tree problems surfaced with greater than usual <br /> intensity in June . The first was oak anthracnose , a fungus whose <br /> symptoms are seen mainly as browning and curling leaves in the <br /> lower portion of white and bur oaks. Most trees have by now <br /> fully recovered . A second and more severe problem was birch leaf <br /> miner on white or paper birch. The brownish resulting leaves <br /> caused much stress to these trees. Those birch trees even those <br /> slightly weakened become targets of the bronze birch borer which <br /> usually leads to the death of the tree over a 2-3 year period. <br /> Next year should show more dying birch than usual . <br /> Other minor problems seen were bacterial wetwood on several <br /> species , mountain ash sawfly, long spruce cone gall , maple • <br /> bladder and velvet gall on soft ( silver ) maple , rose chafer and <br /> apple scab fungus. <br /> No reports of fireblight bacteria or verticilium wilt on maples <br /> were recorded . <br /> TREE ORDERS FOR 1984 <br /> The purchase of approximately 200 new trees is planned for 1984 . <br /> Silver View and City Hall Parks will receive most of this new <br /> stock. The trees will be used for replacement of any vandalized <br /> or failed plantings of the past two years and for the continued <br /> screening of Highway 10 to the northwest. An additional 40 trees <br /> are expected from donations and City nurseries . <br /> • <br />