When it comes to urban plants and trees, the Japanese beetle is one of the most destructive pests in the United States. It’s no wonder a question commonly asked of pest management professionals is, ‟Will Japanese beetles kill my tree?” It depends. First introduced in New Jersey, this invasive beetle has now spread north to Ontario and Minnesota, west to Arkansas, Iowa and Missouri and south to Alabama and Georgia. The Eastern portion of the United States provides a near perfect climate for this voracious pest. So, what do these beetles look like and what plants do Japanese beetles eat?
Looks can be deceiving. Both the adult and larval (grub) stages of this beetle cause damage, so it’s important to know what each looks like. The adult Japanese beetle has an attractive appearance – its body is bright metallic green and the wing covers are a copper color. It also has white spots of hair under the wing covers on each side of its body. The adults are small, measuring between one-third and one-half of an inch in length. Grubs are white colored with tan or brown heads. A fully matured grub is approximately 1 inch long.
Lots on the menu. When asked, ‟What do Japanese beetles eat?” a more appropriate question might be, ‟What don’t they eat?” Adult beetles are known to feed on more than 300 species of plants. To make matters worse, they feed in groups, starting at the top of the plant and working their way down. This ‟group feeding” behavior is what causes the devastation to the plant or tree. Plants that have been injured by the Japanese beetle give off an odor that attracts even more beetles, thus compounding the problem. Japanese beetles are very mobile and can infest new areas from several miles away.
But it doesn’t stop there. Adult female beetles lay eggs in the soil, which hatch into grubs. The grubs feed on the roots of turfgrass and vegetable plants. They especially thrive on the kind of high quality turfgrass found in parks, golf courses and lawns. A common sign of a Japanese beetle infestation in turfgrass is large dead spots that can be rolled up like a carpet because the root system has been destroyed.
Foods of choice. Japanese beetles are not picky eaters, however, they do have their favorite foods. Roses, sassafras, Norway maple, Japanese maple, black walnut, gray birch, American elm and practically any type of flowering fruit trees such as grape, pear, plum, peach and cherry are all at the top of their ‟favorites” menu.
Assessing the damage. But that still doesn’t answer the question, ‟Will Japanese beetles kill trees and plants? If the evidence of an infestation is found in the early stages, trees and plants can be saved with the proper care. Removal and control of Japanese beetles is usually best performed by a professional that specializes in lawn care or tree care.
If you have questions about Japanese beetles that are specific to your yard, such as, ‟Do Japanese beetles eat tomato plants?” or ‟Do Japanese beetles eat hostas?” call Terminix® and get advice straight from the experts.