Are Japanese Beetles Getting Intoxicated In Your Garden?

No one will ever make a reality show about gardeners. We tend to be sweaty, disheveled and a bit dirty for starters. Our shoes are functional. We wear big, floppy hats. We’re pretty keen on shorts, pants and sometimes vests with lots of handy pockets. And we love, love to gather together and talk about plants, plant problems and bugs.

Japanese beetles snacking on Virginia creeper

“Does milk really help stop powdery mildew?” “Is aster yellows caused by a virus or a phytoplasma?” “Why that is the largest scale bug I’ve ever seen! And you removed it using a power washer, amazing!”

Yeah, we couldn’t even sell the Gardeners Gone Wild topless version of this stuff.

But we could use your help with a current topic that’s come up this year. Some gardeners around Minnesota have reported seeing Japanese beetles feeding on geraniums and then acting, well, drunk or stoned or something. Jeff Hahn, an entomologist with the University of Minnesota Extension Service says it’s really unusual for Japanese beetles to feed on geraniums because geraniums contain a toxin that “intoxicates” the beetles to the point where they can be paralyzed for hours. (Read more of Jeff’s interesting updates on garden pests here.)

Maybe this is what JBs see when they see geraniums?
Credit: Hector Garcia

Apparently, this experience isn’t half bad because once they recover the Japanese beetles go right back for more. So, if you have Japanese beetles getting blackout drunk on your geraniums, Jeff and others with Extension would love to see some photos. Please email your photos to me, or send me a link to Flickr or wherever you post photos, and I’ll forward them on. Let me know what state you live in, and how long you’ve been seeing Japanese beetles on your geraniums, too.

Oh, and one more thing. Several master gardeners have been wondering whether it would be a good idea to interplant geraniums with roses, grapes and other plants Japanese beetles love in hopes that they would flock to the geraniums and leave other plants alone. Unfortunately, Jeff Hahn says that research has shown that the strategy doesn’t work. In fact, even more beetles show up than before. The upshot? You may not want to plant a geranium beetle bar in your garden unless you want them to party at your house.