How To: Get Rid of Japanese Beetles
Japanese beetles can wreak havoc on your garden—including your flowers, vegetables, and trees. We’ll show you how to get rid of Japanese beetles with five simple strategies.
Japanese beetles might be harmless to humans but that doesn’t mean you want them around. This invasive insect feeds on more than 300 plants and costs the United States more than $460 million a year, according to the Penn State Extension. They’ll eat through plant leaves and even flowers.
As their name implies, these insects are native to Japan but now are found in much of the United States. Adults have a distinct metallic green or bronze color on their backside. They are about 13 mm (½ inch) long with copper-colored front wings.
If you find one Japanese beetle, you’ll find more. But there are some simple things you can do. We’ll show you how to get rid of Japanese beetles with a few different strategies.
BEFORE YOU BEGIN
It’s best to get rid of Japanese beetles as early as possible since once their numbers grow, it becomes more difficult to get rid of them. Also, the beetles are drawn to the scent of ripening or diseased fruits, so keeping an eye on your plants is one of the best prevention methods.
Try a homemade soap-and-water solution.
A simple solution of water and dish soap can suffocate Japanese beetles. Grab a bucket and mix a quart of water with a teaspoon of dish soap. The dish soap doesn’t have to be any particular brand—any will do.
Once you mix the water with dish soap, the least “touchy” solution is to pour the soapy water into a spray bottle and spray the beetles on your affected plants. This can cause the beetles to drop from the plant and possibly become food for predators such as birds.
Pick the Japanese beetles off plants by hand.
One of the easiest methods to get rid of Japanese beetles is by hand. Since Japanese beetles don’t move quickly, nor do they bite or pinch, you can just go to town on those little pests with your fingers (wearing thin gloves if you prefer).
Once you pick a beetle off the plant, place it in a bucket filled with your water-soap solution so the beetle will suffocate and die. When you’re finished, the cleanup is easy since you can just dump the bucket.
Spray the affected plants with neem oil.
Neem oil will kill Japanese beetles before they become adults. And since neem oil is nontoxic, you can spray it right on your affected plants.
Here’s how it works: When male beetles ingest neem oil, they pass it on to the eggs. Then, the hatched larvae will eventually die before they become adults. The best way to kill Japanese beetles with neem oil is to spray the oil before the beetles enter their adult stage so they’ll ingest it before mating.
Set traps away from targeted plants.
Japanese beetle traps are a great way to stop an infestation of these pests from growing larger. Traps work by luring male beetles away and killing them before they can mate.
There are various traps available for purchase, but the main idea is that the trap contains some kind of attractant such as a pheromone (chemical messenger) to lure males to the trap. Then they are killed either by a toxicant or when the trap contains a mechanism to prevent them from leaving.
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Use row covers during peak feeding period.
A row cover might be the best solution to stopping a Japanese beetle infestation before it gets started. Row covers provide protection by keeping Japanese beetles out, but are still fine enough to let in light and some moisture, allowing the plants to continue to grow.
Row covers are best used during peak feeding periods for the beetles, which generally run from mid-June to mid-August. The covers come in different sizes and can be used on shrubs or trees or placed over your flowers, ornamental plants, or garden vegetables.
Even though Japanese beetles are harmless to humans, that doesn’t mean you want to roll out the welcome mat. Remember that once you find one Japanese beetle, there are sure to be more. While it’s best to stop an infestation of these invasive pests early, these tried-and-true remedies for how to get rid of Japanese beetles—with soap and water, neem oil, picking them off by hand, using traps, or row covers—can help ensure your flowers, vegetables, and other plants remain healthy throughout the peak feeding season.