Japanese beetles are small insects that make a huge impact on garden health. These bugs attack most types of plants and eat away at their foliage and flowers, leaving them with holes. Check out this guide of Japanese beetle facts and solutions to keep them out of your yard.
The beetles release chemicals called pheromones into the air. These pheromones attract other beetles. So if you see a few of the bugs, they'll probably attract more. Quick action works as a natural Japanese beetle deterrent. Get rid of Japanese beetles early, before they can invite more of their friends to feed on your plants.
Japanese beetles tend to be most active when temperatures are over 85 degrees Fahrenheit and the air is relatively still. Be especially watchful for new beetles coming into your yard during these conditions.
While it's the adult Japanese beetles that cause the most damage, their larval form—grubs—can also cause lawn problems. If your lawn has a Japanese beetle grub infestation, treating for the grubs will kill most of them before they can emerge as adult beetles. A number of grub-killing products are quite effective. There are also organic options for grub control including beneficial nematodes.
If Japanese beetle infestations are light, the safest and most inexpensive route to killing the beetles is to pick them off the plants by hand. Then, drop them into a bucket of soapy water rather than using a Japanese beetle spray. By using soapy water, you are sure that each beetle has been dealt with.
A number of pesticides are available for Japanese beetle treatment. Some ingredients to look for on pesticide packaging include carbaryl, acephate, and permethrin. Organic, neem-based pesticides can also provide good control, as can insecticidal soaps. Editor's Note: Insecticidal soaps will kill the beetles, but won't provide any ongoing protection to your plants.
University research indicates that using Japanese beetle traps can actually make problems worse. The traps are intended to trap and kill the beetles in your yard. However, they use pheromones to attract the beetles to the traps, and these pheromones bring more beetles into your yard than the traps can catch. Use other Japanese beetle killer products like insecticides before turning to traps.