08/10/2026
🪲 Garden Alert: The Onslaught of Japanese Beetles 🪲
Have you noticed your prized plants looking like delicate piece of lace? You are likely dealing with the invasive Japanese beetle (Popillia japonica)! These metallic-green and copper pests love a good buffet and feed on more than 300 different plant species. They are especially fond of roses, raspberries, grapes, linden trees, and apples.
Here is what you need to know about the harm they do and how to handle them based on science-backed advice from the University of Minnesota Extension..
🍂 The Harm They Do; Adults skeletonize leaves: They chew the tissue between leaf veins, leaving behind an unsightly, lace-like skeleton.
They ruin blossoms: Beetles eagerly chew large, ragged holes directly into flower buds and open petals.
They attract friends: When a beetle feeds, it releases an aggregation pheromone (scent) that alerts every other beetle in the area to join the party.
Grubs destroy lawns: Below the surface, their larvae (white grubs) spend months feasting on grass roots, causing turf to die and pull up like loose carpet.
🧼 Safe & Effective Management
Start early: Hand-pick the very first beetles you see. Removing them early prevents the buildup of aggregation scents that draw in massive crowds.
The soapy water plop: The best non-chemical control is to gently knock beetles into a bucket of water mixed with a sq**rt of dish soap. Do this in the cool morning or evening hours when they are sluggish and slow.
Skip the commercial traps: Hanging beetle traps actually attract more beetles to your yard than they catch, often worsening the damage to nearby plants.
Look for white spots: If you see a beetle with a tiny white egg attached to its upper body, leave it alone! It has been targeted by the beneficial Winsome fly, a natural parasite that will kill the beetle from the inside out.Don't panic if your mature, healthy shrubs take a beating—they are highly resilient and will survive the summer cosmetic eyesore!
🔗 Learn more about managing grubs and adult beetles: Read the full guide on the UMN Extension Japanese Beetles Page. https://extension.umn.edu/yard-and-garden-insects/japanese-beetles
💬 Goodhue County Gardeners, let's chat: What are they eating in your yard this week? Have you spotted any Winsome fly eggs yet? Drop your photos and observations below
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