When not preoccupied with feeding, the beetles find time to mate and lay eggs (what a life!). Eggs are laid near the soil surface, and the newly hatched larvae tunnel in late summer to overwinter in the soil until the next season. While the adults feed solely on trees and shrubs, the larvae feed on grass roots and can cause problems for the turf. Brown patches in the yard that easily pull up are a sign of grub issues. On top of that, it’s not uncommon for animals such as skunks, opossums, and raccoons to dig in the yard for a tasty treat.
On a positive note, Japanese beetles can be controlled to minimize damage. If you’ve had issues with grubs killing the lawn, you or your lawn company should put down a granular insecticide early in the spring to help kill grubs. Most professional lawn services have this built into their maintenance program. This can help your lawn but won’t do much for your trees, as the beetles will still fly in from neighboring sites.
Treatment for trees is best done preventatively using systemic insecticides placed in the soil that travel up through the roots and into the leaf tissue, thus killing the beetles as they feed. It's important to note that none of these treatments act as repellants. The beetles must feed on the leaves in order to die. The timing and chemical required depend on the type of tree or plant. Birches, elms, buckthorns, and other non-flowering trees and shrubs can be treated with imidacloprid in the spring once a year, at least a month prior to beetle emergence. This product is not registered for flowering trees, however, as it has been associated with the decline in pollinator populations. For lindens and fruit trees, acephate can be injected in the soil at the time of beetle emergence, which can provide 4-6 weeks of control. For last minute applications when systemic insecticides will be too slow to be effective, foliar sprays will be effective. Sprays with bifenthrin or permethrin will provide two weeks of control, and will need to be repeated until mid-to-late August when the beetles stop feeding. (Yes, Arbor Aesthetics offers all of these treatment options!)
Traps: Are they effective?
A common question is whether or not to use pheromone traps in the yard. The short answer is NO. Don’t do it. Studies have shown the traps bring in more beetles than they catch, and will draw in beetles in from an even larger area.
Dylan Willis, Plant Healthcare Specialist
B.S. Forest Science
ISA Certified Arborist
My grandmother always had trouble with Japanese beatles eating her rose bushes. She would put out traps, but it never seemed to help. I wish I had known the ineffectiveness of pheromone traps and could have told her to avoid using them. Thanks for the hepful advice!
7/11/2018 06:37:51 pm
This is a great article! I know this is in Omaha but I wonder if they are in Arkansas this sounds very familiar to what is happening to my fathers plants and trees!
8/4/2018 12:32:47 pm
Any suggestions on ways to keep these beetles from snacking on strawberry plants and other garden items?
11/15/2018 04:51:51 pm
These things are a real pain. Whatever you try, do use those yellow bags with the pheromones - they just attract even more beetles.
11/26/2018 11:29:12 pm
Wow I haven't seen those in California, but this is some good information to know. Seems like these can Japanese beetles be a real pain.
12/3/2018 05:34:42 am
Very helpful information for keeping our trees healthy, and our people safe. Thank you for sharing!
10/2/2019 06:00:31 pm
This bugs are pest. It needs to be killed when the moment it comes in your garden. Well, this article explain how to get rid of it. Thanks for sharing this.
10/23/2019 02:11:13 pm
Very helpful information for keeping our trees healthy, and our people safe. Thanks for sharing it!
10/23/2019 02:12:20 pm
Very helpful information for keeping our trees healthy, and our people safe. Thanks for sharing this
10/23/2019 02:13:25 pm
Very helpful information for keeping our trees healthy, and our people safe. Thanks
10/23/2019 02:14:03 pm
Thanks for sharing!
10/23/2019 02:15:28 pm
Thanks, awesome content
10/23/2019 02:16:12 pm
Thanks, this is superb!
11/15/2019 07:12:13 pm
Wow, thank you! old but gold about maintaining the health of our trees.
11/19/2019 09:57:28 pm
Very useful and delightful information! You light up my day.
12/4/2019 08:41:40 pm
Those little suckers are killing my blackberry bushes and rose bushes
12/5/2019 01:25:21 am
I remember growing up, my family and I used to go outside and flick hundreds of these off the roses weekly
12/5/2019 09:01:57 am
I may try this the Japanese beetles are eating my cabbage like there's no tomorrow
12/5/2019 10:11:57 am
My garden has been suffering from Japanese beetles infestation for 4 years.
12/12/2019 11:26:43 pm
12/5/2020 02:53:56 pm
Wow, interesting how much these little guys can do!
2/19/2021 05:08:15 am
Great stuff! Thank you
5/18/2021 11:57:59 am
Amazing full of information website. you guys are making huge progress, keep it up! I look forward to reading your work in the future.
7/22/2021 06:42:38 pm
Wow! what a complicated creature. Awesome post!!!
12/2/2021 01:32:13 am
Excellent article! Your post is essential today. Thanks for sharing, by the way.
3/1/2022 05:18:33 am
Thank you for sharing informative content. It means a lot to me hope you do more articles to post.
11/1/2022 01:31:48 am
Great blog. I appreciate you giving all of this useful information. The information was both quite fascinating and very helpful. Without a doubt, this content is worth to share!
3/2/2023 10:56:54 am
I think this is really informative! Thank you for this!
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Amy Grewe, Certified Arborist & Co-Owner