If you’ve spent any time outside in the past couple of weeks, you’ve likely seen numerous beetles flying about. They have metallic green bodies, coppery wings, and little white tufts of hair on the side. They are Japanese beetles, and they are a force to be reckoned with.
They have been in the United States for almost 100 years but are just now making their way to the Midwest, as winters haven’t been cold enough to control the larvae/grubs, which will damage lawns as they eat the roots.
An affected linden tree. |
Your first instinct is probably to break out the pesticide but hold that thought. The only pesticides that work require special handling, cause damage to humans and the environment when improperly used, kill beneficial insects (including pollinators) and are unsafe for edible plants, pets, wildlife and waterways.
So what can you do?
Get rid of the adults.
- Brush them off and drop them into soapy water. Stop the adults now and avoid the eggs they would lay.
- Don’t use pheromone traps. While effective, they will attract more bugs to your yard, as Japanese beetles can fly five miles when motivated.
Control the grubs without hurting the beneficial insects you are working to attract:
- Apply milky spore. Grubs eat it, die and release more spores, which infect more grubs. It takes three to five years to be effective but provides a longer-term solution as it becomes established in the soil.
- Apply parasitic nematodes (Heterorhabditis bacteriophora) to your lawn to eat the larvae. They are effective if properly watered in and the ground kept moist.
- Apply Bacillus thuringiensis to specifically kill grubs.
- Use a product containing azadirachtin, the insecticidal ingredient found in neem oil. This concentrated spray is approved for organic use, and, best of all, it’s nontoxic to honey bees and many other beneficial insects.
- Attract birds. Robins, bluebirds, and others will eat the grubs.
- Don’t overwater. Grubs do better when the ground is moist.
- Plant less grass. You decrease maintenance time and expense, and they have less to eat.