Pest of the Week
If your garden is attacked by Japanese beetles, the results can be devastating. Some consider these small but furiously destructive beetles the most invasive pest in the eastern United States. They’re also found in parts of southern Ontario and isolated areas of Quebec. These metallic green and copper insects, which are only about ½ inch long, wreak havoc from Wisconsin south to Alabama and east to the coast. Japanese beetles were accidentally introduced into the United States in 1916 in New Jersey. Previously, the beetles were only found in Japan, where they were not considered a major pest.
Japanese beetle larvae, or grubs, live in the soil for 10 months. The C-shaped grubs are white with a yellow-brown head, and they feed on vegetable seedlings and the roots of turfgrasses. In June, they begin to emerge from the ground. Adult beetles feed on about 300 species of grass, fruit, and flowers. Although they live for only 30 to 45 days, they can do considerable damage in that time. Japanese beetles are skeletonizers, which means they eat leaf tissue but leave the veins. Attacked leaves often look like pieces of lace, and they eventually wither and die.
There are a few ways to handle Japanese beetles. If they’re a problem in your area, don’t choose plants that the beetles are known to love, like roses, grapes, Japanese maple, rose of Sharon, crabapple, and purple-leaf plum. If you already have Japanese beetles in your garden, try to shake them off plants in the early morning when the beetles are most sluggish and drop them in a bucket of soapy water. You can also apply milky spore bacteria—sprinkle it on the lawn to kill the beetles at the grub stage. Products that contain parasitic nematodes are also effective. (Nematodes are small worms that eat an insect from the inside out.) As a last resort, look for insecticides that kill Japanese beetles in both the grub and adult stages. Check with your local extension service to see which insecticides are recommended in your area.
—text by Elyse Lucas, photo courtesy of the Kemper Center for Home Gardening at the Missouri Botanical Garden
Wednesday, July 21, 2010 10:50 AM
I have been battling these insects this year, I have not had them before. I used seven dust and dusted my roses with it, and I have also just knocked them off of my plants. They are a very destructive insect.
Wednesday, July 21, 2010 6:11 PM
Yes they are definitely back in full force this year. I have always used sevin dust and kept them somewhat controlled. But I have so many birds and butterflies in my yard I am hesitant to use it this year. Is there any eco-friendly pesticide which is effective on them?
Thursday, July 22, 2010 6:31 AM
You can get traps. I used one last year, and this year I'm really wishing I had. You hang the trap and a bait attracts the beetles. They fall in the trap and "tada"!
Thursday, July 22, 2010 7:55 AM
I used to use the bag traps, but many articles I've read say that they attract the pest to your garden. Finally, a few years ago I bought milky spore and I have seen a dramatic decrease in the beetles on my property and I have 5 acres! Milky spore is my recommendation.
Thursday, July 22, 2010 8:00 AM
Sevin is very toxic - I avoid that at all costs. I pick them off by hand when it's cool - early morning or dusk - and put them in a container of soapy water to kill them. Buy milky spore and start using it this year - the sooner you get it in the ground the quicker it will work on the grubs. I saw results in 1 year eventhough the directions say it can take 3 years to see any results. They are nasty little beetles!
Thursday, July 22, 2010 9:27 AM
Yesterday I used a solution of dawn dishwashing liquid and water and sprayed it on some of my plants, needless to say the beetles couldnt handle it. It isnt harmful so Ive been told to butterflys and birds, my husband uses this solution to kill wasp, and we have never noticed it affecting any other thing.
Thursday, July 22, 2010 9:29 AM
I do plan to purchase the milky spore you all have recommended. Thank You for the information.
Friday, July 23, 2010 8:43 AM
this is the first year my roses are doing well. Or they were,these beetles are bad. Soapy Dish detergent is what I use.
Saturday, July 24, 2010 4:24 PM
I use a Safer Soap mixture in a spray bottle. I buy the concentrate because it cheaper that way and mix it up a quart; at a time. I go out first thing every morning when the beetles are out and spray it directly on the hateful little critters. Very effective. I have also applied nematodes on my lawn (this year) and hope it helps decrease the number of beetles I have to deal with each year.
Our yard is a haven for birds and butterflies (we have 9 feeders and 3 birdbaths) and lots of flowers the butterflies like. I don't want to use anything that might harm them.
Sunday, July 25, 2010 7:07 AM
They all most stripped my tree of leaves
I used the Milky Spores but my neighbors didn't so I still got infested with them
I found a Brew online that seems to work for me
fill a gallon sprayer 1/2 full of water
add 1 cup dish washing soap-1 tablespoon of Garlic powder--1 tablespoon full of cayane pepper then fill the sprayer the rest of the way with vinger--spray only in the early morning or late evening & never in derict sunlight
Monday, July 26, 2010 11:56 AM
I also avoid the Sevin dust. I bought some to use on my rose bush but I have a Butterfly Bush growing right next to it. The bees love the Butterfly Bush and I was concerned what the Sevin Dust might do to them. I called Sevin customer service and they told me that unfortunately the dust will kill the bees as well as the Japanese Beetles. I purchased some Spectricide this spring and applied it to a few small areas of my lawn. It seems to have reduced the beetle population this year. I will be using again in larger areas next time. I go out in the morning with an old dutch oven and whack the beetles into the pot with the lid. I leave it out in the sun to cook the little buggers.
Tuesday, July 27, 2010 12:42 PM
I once sprayed something on the grass that said it would get rid of grubs in the lawn. I imagine it did, but I also noticed that all the earthworms crawled up out of the ground and died! No more "grub killers" for me. Milky spore, nematodes. Even if it means sneaking into my neighbors yards at night and spraying them too!
Tuesday, July 27, 2010 2:01 PM
I have had an awful time this year with the gardens, from fungus' from the humidity to these evil little beetles I have to fight to get to my blackberries, they finally won and have eaten all but a handful or two of them, so no jam this year. I am gonna try the soap bath and see if it works, don't know about Dawn tho as I am extremely allergic to it (it eats my skin like acid) has anyone tried other detergents with success? I tried the pepper and garlic spray (word to the wise, do not spray it when you are downwind..lol) but it has either washed off or just didn't work at all. I am also having issues keeping the squirrels out of my garden, they steal my vegetables and sit in the tree and throw pecans at me. Any suggestions there?
Friday, July 30, 2010 9:09 AM
All of these methods seem to work so I use a combination of soapy water, had picking by hand. I just applied nematodes and mily spore so I won't know if it works for a while but I've also read that nematodes help with fleas and ticks so I'm hopeful. The traps even help but you have to have a large yard and place the trap away from the infested area. If you put the trap close to your plants it draws the beetles into the area you want to keep them out of.
Friday, August 06, 2010 9:23 PM
One friend of mine told me that in a very old gardening book she read that you should keep small areas of water in your garden. Either a decorative cup or decorative bowl. This attracts the good insects that eat the bad. I thought I would try this and so I placed a large decorative bowl in the center of the garden on a broken bird bath. The birds did not use it because the bowl was to slippery. However I was in awe at how many Japanese beatles were dead in the water. So I placed a few more of these decorative bowls here and there around the yard and still more Japanese beatles had drowned in the water. Now I am hard pressed to find a beatle in my yard. I am sure they are there but I just don't see them much anymore.
Tuesday, August 24, 2010 7:07 PM
I got my garden under control from pests and these beetles by using neem oil, castille liquid soap (organic) and water put in a spray bottle spray all your plants, flowers, trees, veggies and fruits down not only is it safe for adults (keep out of reach of children) but it rids your garden area of most pests and you can use it as needed won't hurt your plants, fruits or veggies. Just gently wash your food after you pick it you don't have to worry about consuming it as it's all natural. You don't want children to handle the neem oil in it's pure form as it can make them very ill as it's strong stuff. I found all this at mountainroseherbs.com I've used their stuff in my gardens for over ten years and very rarely do I get an infestation and if I do spraying it with this formula rids my problem in about a 5 day time window.
Wednesday, December 01, 2010 1:14 PM
Here in my Southern california garden they do not seem to go for leaves. They go for the fruit! They ate at least half my nectarines last year.
I am going to try picking them off in the early morning and check out the milky spore or neem oil, whichever I can find.
Wednesday, January 12, 2011 9:58 AM
Be a "hero" and give out the Beetle trap bags to your close neighbors, That way the beetles stay in your neignbors yard and not yours. Hee Hee
Friday, July 01, 2011 2:56 PM
I have a question for slater1976, what are the proportions you used of the neem oil, castile soap and water? the beetles are chewing away my bell pepper leaves and roses.
Friday, July 15, 2011 6:10 AM
I use a torch. Sounds mean, but they get what they deserve! I hate the little buggers!
Friday, July 15, 2011 10:34 AM
I had a huge issues with these bugs, do to the Japannes Mapels Trees, Japannes Tea roses, and a Weeping Cherry Tree. I used a 4 products to kill these bugs. First I tried Seven Dust, only to find out it is only a temporary fix. Then I used a the Japaneses Traps, did not help at all, but I think I had gotten them. I had put out some Spectacide through out the yard, and then the biggest help of all was the Bayer Advance Tree& Shrub Protect and Feed. The last one was the best result of all. A must have to keep your yard looking great and pest free.
Monday, September 05, 2011 9:40 AM
I live in Central Maine and have had quite a battle with the beetles this year (but not last year!!). They ate almost all my string bean leaves, raspberries, and especially my basil...I used the traps--two things to say about that...I put them too close to my crops so attracted them and didn't use enough traps...Next year I will be more prepared for the infestation...Does anyone know if weather plays a role, like too much rain??
Wednesday, July 11, 2012 5:03 PM
They are constantly attacking my petunia and hiding under the leaves of my Zinnia. I have been picking them off and squishing them. They seem to invade mostly when the sun begins to go down. Not as much in the sun. Arg! they are so annoying! I spend so much time on my flowers just to have them destroyed. I will try the soapy mixture.
Friday, July 27, 2012 12:17 PM
I get these "bad bugs" in my garden every year. Usually they go after my bean plants. I handpick them and drop them into a water bottle filled with soapy water. I also have a few stands of bamboo, not sure what kind, that grow near a few of my gardens. Though I can't stand the bamboo, I leave a few patches for the Japanese beetles to feed on. The beetles are attracted to it and it helps keep them out of my garden. So far this year they've only attacked the bamboo and I'm hoping it will stay that way.
Tuesday, October 23, 2012 8:00 PM
@ Jilteed---Hahaha!!! I've thought of that! This year my Canna & Roses were destroyed by these nasty bugs! I do enjoy picking them off and feeding them to my Coi ! Sweet revenge :)