01-31-85 Agenda & Packet - Laserfiche WebLink

Home Browse Search

OTHER TREE DISEASES Tree diseases of shade and ornamental trees had an average .. year in Mounds View. oak anthracnose was presen[ but not � nearly as damaging as in previous years. Fireblight. apple scab/rust and verticillium wilt were not present in any great amount. Uncommon diseases seen in 1984 included cytospe�a on blue spruce IAead and dyiny lower branches) and powdery mildew on floweri�y crabapple. Much oE the severe winter damaye was mistaken for tree disease in t�e case of mountain ash, white ash and Norway maple. DAMAGING TREE INSECTS Most populations of tree-damaging insects were down in 1984. Cankerwrm and linden looper activity in the spring was barely noticeaAle. The more common of the gall problems seemed less significant as well. Only long spruce cone gall showed any increase over previous years (on Colorado blue spruce and Douglas fir). Fall webworm was again present, but in no great numbers. it does, however, appear to be more widespread than in [he past. Other insects promptiog citizea concern aece the imported wil- low leaf beetle, rose chafer beetle, jackpine sawfly, as� plant buy and the birch leaf miner. GYPSY MOTH By far, t�e one greatest potential threat to all trees in Mounds View is the gypsy moth. T�is insect, an efficient defoliator in the larval stage, shows a preference to eating oak foliage, but will feed on any tree species including pine and spruce. For t�e second consecutive year, multiple catches of the adult ma16 moth have turned up in State anA Fedecal attractant traps in [he Rnollwood Drive/WOOdale Drive area. A thoroug� foot seare� for eyg masses in the area by five Ftate/Federal ccews yieldetl no results. Thus, the source oE inEec[i�n is still unknown. Egg masses were found in three ot�er commu�ities in the fall of 1984. T�ese will all Ae aerial sprayed in the sprinq of 1985. As no masses or other life stages of the moth were found in Mounds View, no spraying will be done here. Increasetl trapping will take place in 19R5 with hopes of pin- pointing the infection source by fall.