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April is Oak Wilt Awareness Month!

This spring and summer, be on the lookout for Oak Wilt! This fungal pathogen can be found in 61 Michigan counties, and may kill as many as 149 million trees. Spread of oak wilt is highest between April and July, and prevention is crucial to preventing its impact. What is Oak Wilt? Oak Wilt is a disease caused by the fungal pathogen Bretziella fagacearum and primarily effecting red oaks. The fungus grows in the vascular tissue of infected trees, blocking water transport and causing trees to wilt and die. White Oaks may also be affected, but the impact is slower and less likely to spread to nearby trees. How can I identify Oak Wilt? Trees infected with oak wilt often have distinctive fruiting bodies called spore mats, surrounded by discolored pressure pads. These spore mats typically form in spring and summer months when conditions are damp. Wilt can also be identified by the rapid loss of leaves during the summer. Fallen leaves are typically brown or partially bronzed, and will appear dried out and wilting. Wilting typically begins at the top of the tree, with affected leaves turning a paler green. How does Oak Wilt spread? The spore mats of infected trees give off a sweet-smell, attracting sap beetles and other insects. These insects can then spread the spores to wounded living oaks, infected cuts with the fungus. To prevent the spread of these spores, avoid damaging or wounding oak trees, especially between April and July, when these bugs are most active. Oak wilt may also travel through root systems to infect healthy trees. This is most common in Red Oaks, which have extensive root systems connecting them to other nearby oaks. The fungus can also travel long distances through the movement of firewood. Oak wilt spores can remain active in wood even after the tree dies, and moving firewood can spread the infection. How can I treat infected trees? Unfortunately, there is no treatment for infected trees. When an infected tree is confirmed, the only option is to stop the spread to nearby trees. Removing an infected tree without cutting it off from the root system will not prevent spread, and could result in healthy trees becoming infected. How do I prevent oak wilt? There are a few crucial steps you can take to stop the spread of Oak Wit: DO NOT prune or trim your trees between April 15 and July 15. DO NOT move firewood. It may be infected with oak wilt, and moving it could spread the fungus to healthy trees. If you suspect a tree is infected, contact us at the Saginaw Bay CISMA at, for identification, or the Department of Natural Resources Forest Health Division at You can also report invasive species using the Midwest Invasive Species Information Network (MISIN) online reporting tool, or download the MISIN smartphone app and report from your phone at

Spotted Lanternfly? In Michigan? It's more likely than you might think!

The spotted lanternfly (Lycorma delicatula) has only been seen in the United States since 2014, but it's causing real havoc in Eastern states. This insect costs the state of Pennsylvania an estimated $324 million a year, and more than 2,800 jobs by weakening and damaging crops. Although live insects have not yet been spotted in Michigan, their tendency to lay egg in vehicles and freight obund for interstate travel mean it's only a matter of time before they are. That's why the Michigan Invasive Species Network considers the spotted lanternfly a "watch list species" with the potential to cause real problems for our economy, environment, and public health. Where did it come from? Spotted lanternfly is native to Southeast Asia. It is believed to have come to America on the exotic tree-of-heaven plant. The tree-of-heaven, which was originally imported into the U.S. as an ornamental and erosion control species, is a common invasive in much of the Eastern U.S. and is a preferred host to the spotted lantern fly. Lanternfly egg masses were likely transported into the United States on imported tree-of-heaven. Since their introduction, spotted lanternfly have been identified in at least 12 counties in Pennsylvania, and has been spotted in Delaware, Virginia, New Jersey, Maryland, Ohio and New York. Why is it dangerous? Although it prefers tree-of-heaven, spotted lanternfly is known to feed on as many as 70 species of plants, including fruit trees, grapevines, and several hardwoods. High densities of this insect can reduce the vigor of, and even kill, host plants. As sap feeders, spotted lanternflies pierce the bark of their host plants to feed, creating a wound that allows plant pathogens to infect the tree. They also excrete large amounts of honeydew while feeding, attracting other pests, such as hornets wasps and ants, that may continue to harm the tree. This build up of waste also allows sooty mold and fungi to grow on the trees, which can inhibit plant growth and cause death. How does it spread? The most common way spotted lanternflies spread is through accidental transport of eggs and egg sacs. Females are poor fliers, but their eggs can travel long distances on truck beds, rail cars, and freight material. Eggs masses can attach to nearly any surface, including vehicles, outdoor equipment, or lumber. Unnoticed egg masses can be moved by accident as part of freight transport or normal interstate travel. What can I do? Slowing the spread of spotted lanternfly is important to minimizing their impact. If you are in an area where spotted lanternfly is present, check vehicles and outdoor equipment for egg masses by following this checklist from the Pennsylvania Department of Agriculture. Do not move nursery trees, firewood or mulch out of quarantined areas. A common treatment in Pennsylvania involves wrapping tree trunks in plastic wrap coated with sticky substances to capture feeding nymphs. Surround the sticky wrap in wire or mesh to prevent birds or small mammals from sticking to the tree. Removing seeding trees-of-heaven from the area also appears to reduce populations abundance. Another solution involves treating so called non-seed producing "trap trees" with systemic insecticide to kill the feeding nymphs and adults. Consult a certified pesticide applicator or MDARD official before pursuing this course of action. In Michigan, where live spotted lanternfly have not yet been identified, it is important to identify and report these insects as soon as possible. Take as many pictures as you can, record the location and, if possible, try to collect the specimen. If you see egg masses or other signs of infections on trees, do not disturb them. Note the location, and report your findings to: Michigan Department of Agriculture and Rural Development, or phone the MDARD Customer Service Center, 800-292-3939, or record your finding on the Midwest Invasive Species Information Network online reporting tool.