Japanese beetles defoliating a basswood leaf. / Photo Credit: Wisconsin DNR
By Linda Williams, DNR Forest Health Specialist
Linda.Williams@wisconsin.gov or 920-360-0665
The Japanese beetle (Popillia japonica) is an invasive insect that feeds on many plant species. The adult beetles “skeletonize” leaves by eating the material between the veins.
Adult Japanese beetles feed on the flowers and leaves of more than 300 plant species, including trees, shrubs and herbaceous plants. Forest trees can be defoliated, with open-grown or edge trees suffering the highest defoliation rates.
Japanese beetles favor birch, mountain ash and basswood (linden) trees, but they have also been observed feeding on the leaves of young oaks.
Continue reading “Japanese Beetle Defoliates Some Forest Trees In The North”
Cities, villages, towns, counties, tribes and 501(c)(3) nonprofit organizations in or conducting urban forestry projects in Wisconsin can now apply for a regular or startup 2026 Wisconsin Department of Natural Resources (DNR) Urban Forestry grant. The total 2026 available funding is $559,680, with a possible release of $139,920 of catastrophic storm reserve to fund a second round in March 2026. 
The Wisconsin Department of Natural Resources is partnering with the UW-Madison Division of Extension to host a series of fall workshops on invasive species plant identification and management. Learn about invasive plants in urban settings, focusing on identification, impacts, management and available resources. Dr. Mark Renz (professor and Extension specialist with UW-Madison) will lead the instruction, with Travis Wilson, Matt Wallrath and John Zabrosky assisting. Each workshop will include morning classroom instruction followed by hands-on field demonstrations in the afternoon. The cost of the workshop is $40 and includes lunch. 
The International Society of Arboriculture (ISA) is launching a new credentialing management system and an updated pricing structure, going live on July 15, 2025.
The National Association of State Foresters (NASF) is accepting nominations for its 2025 awards. Only nominations submitted on or before Friday, Aug. 1, through 
*These training opportunities are provided as an information service only and do not constitute an endorsement from the Wisconsin Department of Natural Resources (DNR).
Beginning July 1, 2025, cities, villages, towns, counties, tribes and 501(c)(3) nonprofit organizations in –or conducting their projects in – Wisconsin can apply for a regular or startup 2026 Wisconsin Department of Natural Resources (DNR) Urban Forestry grant. The total 2026 available funding is $559,680, with a possible release of $139,920 of catastrophic storm reserve to fund a second round in March 2026. 
When your newly planted trees are getting comfortable in their new homes, you’ve pulled the splinters from your hands and you find yourself at a desk asking yourself, “What now?”, we have an answer for you.