Lacebugs are causing ?bronzing? of leaves of many trees and shrubs in central Minnesota. A check of the lower sides of such leaves will probably reveal the presence of these lacy-winged insects, their nymphs, black frass (fecal waste) and vase-shaped egg cases. Their piercing-sucking mouth parts are used to feed on the soft green tissue within leaves and cause the ?bronzing? color change. Chemical control on ornamental trees is an option, but formation of next year's leaf buds usually occurs before these insects cause leaf or twig mortality.
Aspen leaf blotch miner larvae were found on August 2nd still in their ?mines? near Hill City in Aitkin County.
Ash rust was reported in woodlots in Renville and Kandiyohi Counties
in late June.
Anthracnose of oak and ash
During the years of drought, we longed for a wet growing season. Now it's here and the trees are being plagued with leaf problems. The 1999 season will be noted as the summer of leaf blights. Most homeowners blessed with yard oaks are sure that they have joined the parade of calamities and now have oak wilt. But they don?t, it's merely anthracnose. Anthracnose blight of oak and ash species are commonplace all over the state this spring and summer. See the following article to distinguish anthracnose from other oak maladies.