A Gardeners Forum Forums Gardening Reference Gardening in 2004 How to get rid of Japanese Beatles

I live in northern VT and I have a ton of Japanese beatles which eat the leaves of my vegetables/fruits, especially my snap peas and raspberry bushes. While they riddle the upper leaves of these plants with holes, I don't know if they do any real damage...but I still want to get rid of them. I've heard that japanese beatle traps ultimately attract more beatles. I've also read that beneficial nematodes can be effective. Can anyone offer me suggestions on what will effectively get rid of these pests?
Thank you!
Brendan

Hello Brendan,
Welcome to The Garden Helper's Forum!!!
We are very glad you found us!!!

I will see if our resident "Buglady" here can help you with that question!!!

In the meantime, you can do a FORUM SEARCH and type in JAPANESE BEETLES or NEMATODES and see
some of the previous posts on those very subjects..
That may also lead you to some help!!!

Weezie

Yes, nematodes can help you a lot to control the white grubs of Japanese beetles in your turf. You are getting to the end of treatment time for them. Ideally you need to treat Japanese beetle grubs in October with nematodes. This will help control the population for next year. Now nematodes will not control beetles that fly in from other areas, this is why you DONT use beetle traps, they bring in more adults.

Also next year you might want to spray your plants you want to protect from feeding damage with neem. Recent studies have found that Japanese beetles opt not to feed as much on plants that have been spray with neem oil. More work is being done on this.

Here is a link for more info... Japanese Beetle Info

Good luck and if you have more questions let me know!!

Thank you for your response. I live in northern VT and daytime temps are now generally in the upper 50s and nighttime temps are near freezing. It sounds like a beneficial nematode treatment will have to wait until the spring when soil temps are above 55 degrees.
Do you know if the japanese beatles do any real damage to plants and bushes, other than chomping holes through all the upper leaves?
Thanks again!
Brendan

Yes, they do chomp the leaves, and make swiss cheese of them,
BUTTTTTTTTTTTTT if I remember correctly, it's the grubs they are before they emerge as beetles that eat the root system off of your plants and that weakens them, then when they chomp on the leaves it also weakens them a second time, thus your plant may loose it's vibrancey!!
Over time, that really weakens the plant!!
and then if you just let them be, they multiply and multiply and multiply!!! They are vicious!!!

Weezie

P/S I edited Buglady's URL, just shortened it down so it didn't go off the page for some viewers.

Japanese beetles as white grubs feed also on turf roots. This is what they are more known for, and why they are such a problem in lawns. Now there are other species of grubs that can feed on landscape plant roots systems such as Black Vine Weevil or Asiatic garden beetle. Black vine weevil is a big problem throughout the Northern United States and Canada.

At this point I would wait for spring application but would be sure to use a nematode for cooler climates. Also make sure you check your turf that the grubs are present in your lawn area. No point in treating if they are not present in the grub stage.

Good luck!!

I will definitely apply beneficial nematodes next spring. . .I may also apply milky spore for a long term solution. I may even plant some garlic around my raspberry bushes--I heard beatles don't like garlic. Garlic is great for everything!

Well, milky spore only works on Japanese beetles ... so be sure the grubs you have are Japanese beetles. Also there have been questions over the viability of milky spore, and how effective it really is.

This is from Cornell University...
"Recent research indicates that in some regions of the U.S., B. popilliae appears to be losing its virulence against Japanese beetles. Only 0.2% of larvae collected from field sites showed symptoms of milky disease compared to 1946 with 41.5% disease incidence. Also, a recent field study in Kentucky showed that commercial formulations of B. popilliae were only moderately infective (39-44%), that infected grubs consumed the same amount of roots as uninfected grubs, and that lower grub populations could not be linked to infection. Researchers concluded that earlier reports of success were limited to very high infestations of grubs where other stresses may have increased their susceptibility to diseases."

FYI...

Good luck