01-27-83 Agenda & Packet - Laserfiche WebLink

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r c MEMO TO: Bruce K . Anderson, Director Parks , Recreation and Forestry FROM: Rick Wriskey, City Forester. 1111 DATE: January 13 , 1983 RE: 1982 End of Year Forestry Summary TREE LOSSES Dutch elm and oak wilt diseases accounted for the loss of 102 elm trees and 116 red oaks . This represents a total loss of 1 . 11% of the City ' s total elm population and . 22% of the oak population . This is a 29% decrease in Dutch elm disease incidence over 1981 . Red oak losses were down a total of 31% . Clark Landscaping , the New Brighton/Mounds View 1982 tree removal contractor removed 78 (or 36%) of all marked trees . The average removal cost per tree was $76 . 17 compared to $88 . 25 for 1981 . Four ( 4) major trenching jobs were undertaken in red oak groves to separate the root systems of healthy trees from those of diseased trees . Thirteen ( 13) owners of elm woodpiles were notified to remove potentially dangerous pieces from the piles . All complied . iOTHER TREE DISEASES During the course of the growing season , several other tree diseases were active on ornamental and shade trees such as maple, linden and apple. The most severe disease observed was fireblight bacteria which fatally infects apple , pear and mountain ash . Other less damaging diseases were cedar-apple rust and verticillium wilt. DAMAGING TREE INSECTS Insect damage to trees and shrubs was extremely heavy during 1982 . Again , a major infestation of the linden looper was observed on nearly all heavily wooded areas of the City during the month of May . Additionally , these worms seemed to show a preference to newly planted flowering crabapples , lindens and oaks and fed concurrently •.with both the spring and fall cankerworms . Control of the insects on park trees was attempted by using Dipel (Bt) , an organic formulation. Some success was noted but a stronger control will be looked at for 1983 . The usual spring/summer aphid attacks occurred but minimal damage was realized . It was felt that none of these cases warranted control . Several "new" insects were seen in Mounds View for the first time by 410 this forester. Most potentially damaging was an aphid -caused de- formation called long spruce cone gall on Colorado blue spruce . Others were mountain ash sawfly and forest tent caterpillar .