|
|
Missaukee Conservation District is requesting that Emerald Ash Borer was found in southern Missaukee County in August 2006. For a current map of infestations in Michigan log onto www.michigan.gov/eab and click on "Current Emerald Ash Borer Sites".
Oak Diseases &
Infestations Oak Wilt – A disease caused by a fungus and spread through root grafts or systems. The picnic beetle attracted to an open wound of an infected tree can spread the fungus to an open wound of a healthy tree. This is the reason for no pruning or harvesting of oaks from mid-April to mid-September (from the time sap starts to run until dormancy). This disease is fatal. For more information, use the following link. Anthracnose – A fungal disease that infects leaves and causes brown to black spots on leaf edges and along leaf veins. Anthracnose is most common during cool, wet springs. Microscopic spores of most anthracnose fungi are produced in infected tissues during April and May. The spores are blown and splashed to the buds and young leaves and, with favorable moisture conditions, penetrate and infect the swelling buds and unfolding leaves. Long rainy periods help the fungus to spread rapidly. Rake up and remove infected leaves in the fall. Leaves may be shredded and composted or burned. Burn dead twigs and small branches. Prune to thin the crown while dormant to prevent the spread of Oak Wilt. Thinning will improve air movement and promote faster drying of the leaves. Gypsy Moth – The moth was brought to the United States in 1869 in a failed attempt to start a silkworm industry. Escaping soon after, the gypsy moth has become, over the past century, a major pest in the northeastern United States and southeastern Canada. Although not a real concern the past few years, if egg masses are found, scraping them into a container and disposing of them will help keep them at bay around your home. Parasitic wasps lay eggs in the moth egg masses. This helps prevent the eggs from hatching. Oak Skeletonizer – Sawfly larvae, often called Sawfly slug larvae because of their slime coating used to adhere to oak leaves, feed on the lower surface of the leaves, leaving only a fine network of veins which gives the leaf a transparent appearance. Defoliation starts in the upper crown in early summer and progresses downward. By late summer, heavily infested trees may be completely skeletonized (only the veins of the leaf will remain). MSU Bulletin 2633
Oak Decline - Environmental,
stand, and site factors usually are involved at first. Various insects and
pathogens are involved in later stages. Oak decline usually affects mature
overstory trees and is typified by a gradual but progressive dieback of the
crown, reduced growth, and tree death after several years. Oak decline
involves complex interactions between environmental and biological stresses
and subsequent attacks by secondary pests. Predisposing factors, such as
genetic potential, climatic factors,
Twig Pruner - Preferring oaks, larvae bore into stems and cut off or prune twigs and branches from ¼ to 1 inch in diameter. This causes branches up to three feet in length to fall throughout the growing season with leaves attached. Identification is quite simple. The branch will have a small hollow center, but seem healthy otherwise. To control keep the branches cleaned up and burned. See photo a. Beech Bark Disease - caused by a scale insect and a fungal pathogen, this disease is lethal to all but a few beech trees which seem to have an immunity. This link is provided for more information. MSU Extension Bulletin
If you have question regarding your trees
or forests contact Missaukee Conservation District
|
|
|
