Every region has its fair share of pests, but Japanese Beetles are probably one of the most devastating pests when it comes to grass and landscape plants in the eastern United States. While they are absolutely stunning to look at, with their shiny exoskeletons in metallic, copper and jade green hues, their insatiable appetite for ornamental landscape plants instantly detracts from any aesthetic beauty they might exude.
In the right weather conditions, the beetles will target large areas of pasture grasses and turf, where they set up shop and consider the landscape their feeding ground.
Japanese Beetles Prefer All 300 of Your Favorite Ornamentals
Unlike some plant-feeding insects, such as the Emerald Ash Borer, that are quite specific about their diets and habitats, the Japanese Beetles (Popillia japonica Newman) are not picky at all. They are that brash uncle who walks into the buffet and happily loads his plate with every single entrée, a sample of each side dish and one of every dessert on the table. In fact, Japanese Beetles are known to munch on at least 300 different species of host plants, which means your entire landscape is quivering with fear when they feel the tap-tap-tap of those little beetle feet.
According to the experts at Penn State, homeowners and horticulturists in the eastern United States spend roughly $460 million dollars each year trying to eradicate the beetles larval and adult forms in an effort to mitigate the devastating damage they inflict on trees, shrubs and flowers. Not only that, Japanese Beetles are the Number 1 enemy of our delicious peach crops.
As its name suggests, the beetles are native to Japan, but they found their way onto New Jersey soil (or, should we say, ornamental plants) back in 1916. Since then, they have flourished across the Northeast, despite our best efforts to eliminate them. All we can do is persevere.
Fear the Larva as Well as the Adults
Most of the time, we fear either the larval forms or the adult forms of pests. In the case of Japanese Beetles, we fear them all. Each female beetle lays anywhere from 40 to 60 eggs at a time. These eggs are about 1/16th of an inch in diameter and are an elliptical, pearly white. They hatch about two weeks later as grubs.
The grubs are brownish in color and they are shaped like a “C.” When they are full grown, they measure about 1-inch in length. In order to prepare for their pupal state, where they transform into their adult beetle selves, the grubs enthusiastically feast on a wealth of organic matter, most especially the fine roots of your pasture grass and turf.
The large majority of adult beetles emerge from their pupal state in July, although they begin emerging in June and will continue to emerge through August. Adults only live for about a 30 to 45 days, but that’s plenty of time for them to spend the warm days chomping on the foliage of your favorite ornamental trees and plants, after which they burrow back into your turf for a nice night’s sleep.
Since they eat the leaf material but not the veins (like kids who eat the bread without the crust), Japanese beetles leave behind chewed up leaves with lacey patterns. The leaves quickly turn brown and then drop off the trees. This, as well as the jeweled presence of the beetles themselves, are a sure sign that you have a Japanese Beetle infestation - and that it's time to call a tree and shrub insect treatment professional.
How to Eradicate Japanese Beetles From Your Landscape
Unfortunately, there aren’t any natural remedies for eliminating the Japanese beetles. The only way to really get rid of them is to use a registered insecticide that is carefully and conscientiously applied by a licensed professional. These sprays kill the adults, the larva and the pupae. Pesticides puts a stop to the damage currently taking place, and prevents future generations of Japanese Beetles from hatching.
But Wait! What About Those Eco-Friendly Japanese Beetle Traps?
Those traps you’ve seen, the ones that lure Japanese beetles in via the use of sweet-smelling foods lures. They are a good idea in concept because a single trap can lure in thousands of adult beetles at a time. However, this isn’t enough. Japanese Beetle populations are so prolific that even thousands of beetles don’t put a dent in their overall numbers.
Even worse, the traps actually attract MORE beetles to your landscape – so that ends up creating an even bigger problems. As a result, experts are in agreement that you should not use Japanese Beetle traps!
For now, the best thing you can do is hire Joshua Tree or another certified pesticide sprayer to take care of them for you. Give us a call if you think Japanese Beetles are wreaking havoc on your property. 610-365-2200. Learn more about our insect treatment services.