Prevent Japanese Beetles

Japanese beetles (Popillia japonica) are small, invasive beetles originally from Japan. They are about 1/2 inch long, with metallic green bodies and copper-colored wing covers. While they may look striking, they are notorious garden pests!

These beetles can wreak havoc in a few ways:

1. Plant Devastation: Japanese beetles are voracious eaters. Adults feed on the leaves, flowers, and fruits of over 300 plant species, including roses, grapes, linden trees, and vegetable crops. They skeletonize leaves by eating the tissue between the veins, leaving plants weak and unsightly.

2. Grub Damage: Their larvae, or grubs, live in the soil and feed on grass roots, causing dead patches in lawns. This can weaken your grass and leave it vulnerable to other pests and diseases.

3. Attracting More Beetles: Japanese beetles release a pheromone that attracts more beetles to an area, often leading to large infestations.

If not managed, they can reduce plant health, diminish crop yields, and even kill young plants or shrubs.

Getting rid of Japanese beetles can be challenging, but there are several strategies to manage them effectively:

1. Hand-Picking: Early in the morning, when beetles are less active, you can pick them off plants and drop them into a bucket of soapy water. This is time-consuming but effective for small infestations.

2. Neem Oil: Spraying plants with neem oil can deter beetles. It's a natural insecticide that is less harmful to beneficial insects.

3. Row Covers: If you're trying to protect specific plants, lightweight fabric covers can physically block beetles from reaching them.

4. Beneficial Nematodes: These microscopic organisms target and kill Japanese beetle larvae in the soil, reducing future infestations.

5. Trap Placement: While beetle traps are an option, they can attract more beetles to your yard if not placed correctly. Position traps far away from the plants you want to protect.

6. Plants as Decoys: Japanese beetles are particularly fond of certain plants like roses and grapes. Planting these away from your main garden can act as a decoy.

7. Grub Control: Preventing Japanese beetle grubs from maturing into adults is key. Applying milky spore disease or other grub-targeting products in spring to your lawn can help. You can also apply insecticide/grub killer in the early fall to kill the grubs and prevent them from eating your lawn before they go into a dormant stage.

8. Companion Plants: Some plants, such as garlic and chives, are thought to repel Japanese beetles. Adding these to your garden might deter them.

9. Aerate Lawn in Fall: This can expose grubs to cold temperatures reducing their numbers.