The Japanese beetle (Popillia japonica Newman) feeds on the leaves, flowers and fruits of many grasses and plants. A single female beetle can lay more than 40 eggs in a single breeding season. Once hatched, the larvae feed on the roots and organic matter in the soil of a garden, damaging plants and robbing them of valuable nutrients. A bit of preventative planning and organic control can wipe a Japanese beetle infestation out of the garden.
Incorporate plants into your garden that are unattractive to the Japanese beetle. Adult beetles will not feed on flowering varieties such as pansies, violets, baby's breath, snap dragons, hydrangeas, daisies and lilacs, as well as several tree varieties such as oak, pine, mulberry and juniper.
Set the blade on the mower higher in the summer. Female Japanese beetles prefer to lay their eggs in the soil of shorter grass. Take care not to over-water your lawn as the larvae thrive in moist, warm conditions.
Place a birdbath to attract natural predators of the beetle to the garden. Birds feed on the larvae and will pick grubs out of the grass.
Apply milky spore (Bacillus popilliae Dutky) to the lawn. Milky spore, a naturally occurring, host-specific bacterium, targets Japanese beetle larvae by crippling and eventually killing them as they consume the spores in the soil. As the grubs decompose, new spores are released, providing ongoing protection of the lawn.
Introduce beneficial nematodes to the lawn and garden. Such nematodes are commercially available and usually come in a damp sponge. Soak the sponge in a bucket of water and use it to water your lawn and garden. The nematodes not only control Japanese beetle larvae, but maggots, flea larvae and weevils.
Hand pick adult beetles from the garden. The insects are less active in cool, cloudy weather. Check the garden in early morning or late evening, and place the insects in a bucket of soapy water. Remove grubs from the lawn by pulling back the turf to search for larvae. Attract the larvae with a flashlight in low light and pick them out of the soil.
About this Author
Lydia Stephens began writing professionally in 2009. She has written online for Nile Guides, SheKnows.com and various other Web sites and has been published in "Stringing Magazine" and "Xiamen Wave." Stephens played competitive soccer for 19 years, has been weight lifting since 2007 and enjoys running, biking and sailing. She has a Bachelor of Arts in philosophy from the University of Texas.