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LET’S TALK GARDENING – Are You Ready to Combat Japanese Beetles?

By Doug Hensel
Doug's Blog

IF YOU HAD ISSUES WITH JAPANESE BEETLES LAST YEAR, MORE THAN LIKELY, YOU WILL AGAIN THIS YEAR

The best defense in fighting Japanese Beetles is knowledge. The best strategy in eliminating, or at least reducing the damage done by Japanese Beetles, is through learning the life cycle and applying control measures at the appropriate times. Here we are at the end of June. Are you prepared and ready?

Japanese Beetles will come out of the ground and will fly around and eat on plants for about 30 to 45 days. Here are some ideas as to what you can do to eliminate or reduce plant damage:

WAYS TO REDUCE JAPANESE BEETLE DAMAGE

  1. As gross as this may seem, spend some time with your plants and handpick the beetles off the plants, putting the beetles into a bag. Beetles don’t bite. The more you handpick then the less egg laying will occur thus reducing the population and damage for now and in the future.
  2. You can spray your plants once you detect beetle damage. Spray with pyrethrin or Neem at the first sign of attack. Both are safe and effective in controlling beetle damage on plants.
  3. Another natural spray control is to mix 4 tablespoons of soap with a gallon of water and give all your plants a good, soapy bath. Also, since Japanese Beetles do not like the smell of garlic you can make a mixture of garlic powder and water in a sprayer and spray all plants that you are trying to protect.
  4. Don’t forget about the Japanese Beetle traps, with bait. Place the trap in a remote area away from the plants that you are wanting to protect from damage. The bait will draw the beetles into the bag. Over the past few years, many customers have shared with me how many bags they filled up with beetles.
  5. Yet another effective spray is the BONIDES CAPTAIN JACK’S DEAD BUG BREW. The main ingredient is SPINOSAD, which is an environmentally friendly, certified organic product.  Captain Jack’s Deadbug Brew is toxic to a wide variety of chewing insects and relatively non-toxic to mammals and beneficial insects, such as our bees, ladybugs, and praying mantis.

Be diligent with some or all of these steps this summer and your effort will go a long way in reducing future generations of beetles.

NEXT STEPS

Here is the next step for control: Come September you want to apply a product called MILKY SPORE to the soil. Any Japanese Beetle eggs laid in the soil will pupate into larvae stag which is the white grub worm. While this larvae is on the top of the soil, the larvae will ingest the milky spore and die, and, at the same time will help multiply the amount of Milky Spore in the soil for even more control. Milky Spore is a very environmentally friendly product. Your strategy is to have the Milky Spore kill as many of these grubs in September before they go down deep into our soil for the cold winter months.

The third step for control of the Japanese Beetle population occurs in February or early March. You will want to reapply Milky Spore for further control of the white grub worm. When our soil begins to warm, the white grub worm works its way to the surface and feeds on grassroots, thus damaging our turf.

In a nutshell, your strategy for control of Japanese Beetles starts with hand picking. Place beetle traps in remote areas. Spray the adult beetle with an effective spray. And, put down Milky Spore in September and again in late February / early March.

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16 thoughts on “LET’S TALK GARDENING – Are You Ready to Combat Japanese Beetles?

  1. Thanks for the information, these beetles are eating up my plants! Been spraying Seven Dust on plants not much help.

  2. Karen,
    Don’t forget to try the beetle traps along with continuing using the Sevin. Don’t forget, hand picking them off your plants goes a long way in controlling the damage done on your plants. Good luck. Doug

  3. Very helpful! How do you tell the difference between Japanese beetle damage and fungal damage? Thank you.

  4. Do not use beetle traps! All they do is draw more beetles to your yard. I know from experience.

  5. cynthia,
    The main difference between the Beetle damage and fungal damage is by inspecting the actual damage being done. Beetles chew on the flowers and leaves. Fungal damage would look grayish and wilting. so, I think there is differences in the look of the two types of damages. Doug

  6. Holly,
    that certainly can happen. No question. I have heard this from other homeowners. This is why you want to set the traps into a remote area. Over the years I have certainly heard much more positive comments about the Beetle bags than negative comments. Doug

  7. Japanese beetles are eating the beautiful pink zinnia leaves in my garden. I will try the soapy solution immediately.

  8. We used milky spore one time over all our property and didn’t have problems with Japanese Beetles for 10 years! This year, though, I will be applying it again.

  9. Last year I had so many of these beetles in my yard by the 4th of July, but I haven’t seen any yet this year. When do they typically emerge in this area?

  10. Tyler,
    Good Morning. Well, count yourself lucky for not having any Japanese Beetles so far this year. I saw “so far” because they have emerged a week to two weeks ago. I have seen many. If you applied any control measures last year then it worked. Just keep an eye out for them. Count your blessings if you have no problems this year. Doug

  11. Danya,
    Good Morning. And, good for you for using Milky Spore as a control message for white grub worms / Japanese Beetles. Be ready to apply Milky Spore in September and then a second application around the first of March. Hopefully, using Milky Spore will keep the beetles in check.

  12. Tass,
    Good Morning. Yes, try the soap spray for control. Don’t be afraid to pick them off the flowers by hand. Good luck, Doug

  13. Will the milky spore use and the decline in the white grubs help with the mole population by chance?

  14. Crystal,
    This is a great tie-in question. A major food source for moles is the white grub worm. So, it only stands to reason that less white grub worms = less mole tunneling. So, keep using milky spore and keep the white grub worm in check and you will have less tunneling in your lawn by the mole. Good luck, Doug

  15. Doug….how often should I reapply the soap solution? Is this option harmful to bees? I have already sprayed with spectracide and it apparently hasn’t worked as my crepe myrtles have no more flowers on them, and I sprayed with spectracide as soon as I noticed the Japanese beetles. I hate to harm our pollinators, and hope the soap will be a better option! Thank you for all your great articles!

  16. Marylee,
    First, I applaud you for wanting to be safe to our beneficial pollinators. This is one reason for suggesting a soap and water bath, which should be safe for our pollinators. And, a Japanese Beetle bag is certainly a way to control the beetles without using any harmful sprays. The beetles will be flying around for another couple of weeks and then they should be gone. Good luck, Doug

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