Japanese beetle infestations are horrid. Many advertised solutions do not work. Do not be one of those people that figure that out too late. The solutions below are the best way to help you get rid of them once and for all.
You probably found this page because you have an infestation. I hate them. I bet you do too. And your plants definitely do as well.
Japanese beetles are notoriously destructive to plants because they eat so much, so fast. Furthermore, they lay their eggs in the ground and the grubs hide underground until they reveal themselves the next year as adults.
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At A Glance
These are three different options to get rid of them. Each works through a different mechanism and are the highest recommended product within their categories. Please keep reading below to learn more about each one.
Best Ways to Get Rid of Japanese Beetles
Spectracide Bag-a-Bug is a very effective away to catch Japanese beetles on your property. It has a coverage of over 5,000 square feet. You will literally see it at works within minutes. It uses a pheromone lure to attract them. They eventually fall into a bag trap and will not be able to escape. The lure lasts an entire season. It won’t be long before you have a bag full of bugs. Honestly…its quite scary to see how many of them had been creeping around your yard. And honestly…its gross.
You’ll also want to buy Spectracide’s Kwik stand. The stand hangs the trap at a perfect height to catch the bugs. It also gives you something to hang the lure on away from the rest of your garden.
MAKE SURE to hang these traps away from your plants (at least 30 feet) and preferably away from areas you frequently gather (near patios or doors). These traps work very well in attracting these pests and you do not want them constantly swarming next to you. This could potentially attract Japanese beetles from your neighbor’s houses, but the ultimate goal is one and the same – it keeps them away from eating your plants. You will have to replace the bags every once in a while as they will start to stink as the dead bugs accumulate in the bags. If you don’t mind the smell you can mix the dead bodies into soil as they make good fertilizer.
Another tip, if you have so many dead bugs that you use up the two bags it comes with, you can also set up a soap bucket underneath the trap to catch more of them instead of buying more bags. Simply suspend the pheromone lure with the stand above a 5 gallon bucket. Fill the bucket with hot water half-way and then add some dish soap so it dissolves in the water. You do not want it to be bubbly, simply blended with the water. They will fall into this soap bucket and die inside the bucket.
Once the growing season is over, put the lure in a well-sealed zip-lock back and throw it away. There is some thought that because of the pheromone it may increase the number that appear in your garden or lawn the next season. I do not think this is true. As I said above, you may be attracting more beetles to the trap itself for this season (from neighboring houses), but it should not affect the next season.
Sevin Dust is another great product. You spread it over your rose bushes (or whatever other plant they infested). It contains 5% carbaryl. They will ingest the powder and die soon thereafter. The powder itself is safe for plants (it is not absorbed by plants). The Sevin powder will also kill ants, fleas, and cabbageworms.
The one thing about this option is that even though it supposedly only kills insects that feed on the dust, many users have reported that it also kills certain bugs like bees.
Tips for application: Try to apply the product when there rain is not in the upcoming forecast as this will be washed away. You can try to first water your flowers and then 10-15 minute later, apply the Sevin dust to your plants. The water helps to keep the powder in place (making it more effective). You may need to watch for the re-appearance of Japanese beetles every 2-3 weeks because they tend to reappear, often in smaller numbers. After applying the product, let the powder settle (and/or dry) before allowing pets or kids return into the area.
Milky spores is a long-lasting grub control. You mix it into the soil to kill larvae and grubs as they mature. Generally grub live in the ground for 10 months and finally come out the next season as mature adults. Milky spores is an organic compound that will kill the grub after ingesting it in the soil. It is harmless to other living things including any earthworms in your soil and other beneficial insects. The package covers up to 7,000 square feet.
Milky spores are expensive, but they are the best product to use to prevent infestations from re-occurring the next year. I strongly recommend that you use one of the two products above and also apply milky spores to your soil. Apply it to your soil particularly around where you set up your trap or near your plants that attract them. Apply it anytime from the spring to the fall. You will need a spread to apply it to your ground. After applying it, water your lawn so that the milky spores can make its way into the soil rather than being blown away by the wind.
Everything a Gardener Should Know About Japanese Beetles
Japanese beetles, or Popillia japonica, are small beetles that pose a big threat. They feed on all types of plants, but they particularly like rose bushes.
These bugs eat leaves. And they eat them fast. When they eat leaves, they tend to eat the softer inner portion of leaves and leave the harder stems. This leaves a skeleton-like remaining leaf.
If you see “skeletonized” leaves then you will want to be on the look out for these bugs. It is a tell-tale sign that they are around. Inspect your plant thoroughly. Also look for beetles in the ground underneath the plant as the they tend to be pretty clumsy and fall easily.
Japanese beetles are ½ inch in length and they have a metallic bluish green head, copper back, and tan wings. They tend to appear in groups and multiply incredibly quickly.
They typically lay eggs in the soil in June and eventually small white grubs that are about ¾ inches in length develop. These grubs will remain underground for about 10 months while they grow in the soil. They emerge as adults the next year.
Use one of the above products to help either trap or get rid of Japanese beetles. As alluded to above, a bucket of soapy water kills them pretty quickly. This is why I suggest hanging over the Spectracide lures over a soapy bucket once you run out of bags.
Out of the two options above, I prefer the traps. Even though it may attract more bugs from your neighbors’ property…so what, share the love. The Japanese beetles will be away from your rose bushes or other plants, which is what is the important thing. Also, it is less likely to harm other beneficial insects such as bees. It’s a simple solution and you can see the results right away.
Some people also just go the old fashioned way and remove the beetles manually. I find this to be not as effective, but you can definitely try it. Again, utilize a soap bucket and just take the plant that they are hanging out on and shake it over your soapy water. Some people also use battery-powered hand vacuums to vacuum them up. Manually removing beetles takes a lot of effort and time, but it can be effective.
As I said earlier, the grub live in the ground for over 10 months before they emerge as adults in the next season. Other than killing the adults that are around in the current season, you really want to be controlling the grubs in your soil.
This is where milky spores come into effect. Milky spores work very well at controlling the larvae. The grubs eat the spores as they feed on the soil and they die. The milky spores need about 2-3 years before being fully effective on the next season’s beetles. The good news is that the milky spores remain viable in the soil for years.
I would encourage you to spread the milky spores throughout your lawn, but particularly around plants that attract the beetles and near your trap locations. These are the locations that will have the highest concentration of grub.
Again, I recommend buying the Spectracide traps (placed far away from your plants and places with a lot of foot trap) to get rid of the adult Japanese beetles this season and milky spores to get prevent repeat infestations in the seasons to come.