Wal-Mart was selling some Japanese beetle traps and I bought one to try. Those critters love my cherry tree. The tree turns brown from them chewing up the leaves.
My advice on the traps is to move them far away from the things you want them away from. Japanese beetles will come from miles away. The one time I used them, we one had a quarter of an acre. Every JB in Ohio came to my yard. Never again until I got more property, then stick them on the outskirts of your yard.
Our ‘local’ gardening guru (although he’s known nationally) Andre Viet & his son, have a radio program on Saturday morning. In the past, I’ve heard them talk about Japanese Beetle traps.
You do not want to put the traps close to your tree - the traps actually attract the beetles & not all are going to end up in the trap! The traps should be on a “perimeter” around what you want to protect, but some distance away. Most people put them right next to whatever plant the beetles are munching on and that is not a good thing, per the Viets. I’ve been to his place - really neat.
Here’s a link that says the same thing about beetle traps:
https://oldworldgardenfarms.com/2021/07/01/get-rid-of-japanese-beetles/
#1 Avoid Using Beetle Traps – How To Keep Japanese Beetles Away Naturally
“First and foremost, it’s important to realize that if you are using beetle bags or beetle traps in your yard, they most likely are causing more harm than good. Especially if your property is a few acres or less.
Japanese beetle traps work by emitting a scent that attracts beetles into an area. Although the traps do lure in large numbers of beetles into the bag, they unfortunately bring even more beetles to your yard.
To properly protect plants, traps need to be placed far away from the plants you are trying to help. If not, they simply attract your neighbor’s beetles into your space as well.
To be effective, beetle bags need to be placed at the edge of a property, acres away from where you are trying to lure them away from. Unfortunately, in most cases, the average yard is just not big enough.
The result? The bags actually attract even more beetles that can then mate, and lay more larva in your soil to become an even bigger problem next year! Quite simply, for most situations – they are better to avoid.”
Butting in, even though you didn’t ask me. :)
The most effective way to combat Japanese Beetles is when they are in the ground.
So, like all beetles, except for John, George, Ringo and Paul, they start out as larvae. They are in your LAWN, and munch on the tender roots of grass.
They emerge in July (ish) to eat everything in site, to mate and to die. Luckily, their window of opportunity is only a few weeks, but they get a LOT of damage done in that time!
The females return to the lawn, lay eggs and die. I hope it hurts and hurts bad!
So, your best bet for control is to use a granular grub control on your lawn. You just roll it out as you would Weed & Feed or fertilizer. May and June are the best months for application. I THINK you can do a late fall application, too - but I can’t remember off top. I’ve been ‘out of the biz’ since 2016 and some things have fallen out of my brain.
They like my roses and grapes. I don’t have too many beetles most of the time, but when I see them I use Seven, which is a spray I hook up to the hose and douse the grapes and roses.
I also use the Bayer Rose drench which takes 3 applications, but is 100% worth the effort. That stuff works miracles!
They also like Raspberries, but I have ‘Heritage’ so I cut the canes down to the ground in spring. That way I’m only getting ONE crop, and it’s a late on August/September and the beetles are usually gone by then, so they don’t pester my Raspberries.
First, ya gotta be smarter than the bug you’re dealing with, LOL!
P.S. If you want traps, buy them and give them to your neighbor. The beetles will go over there. *SMIRK* Kinda mean, but it works, LOL!