Wicked Bugs Poisoned by Wicked Plants


Beetle Photo by Stephen Ausmus, ARS

This is awesome.   The USDA is doing research into the potential of geraniums to fight back and actually kill Japanese beetles.  Now, I'm lucky not to have to deal with these pretty-but-still-really-horrible beetles here in California, but I'm sure it's only a matter of time.  So I find the USDA's graphic description of the beetles' death remarkably satisfying:

Within 30 minutes of consuming geranium petals, the beetle rolls over on
back, its legs and antennae slowly twitch, and it remains paralyzed for
hours. The beetles typically recover within 24 hours when paralyzed
laboratory conditions, but they often succumb to death under field
after predators spot and devour the beetles while they are helpless.

Great stuff.  Keep it up, USDA.

Oh, and by the way.  Wicked Bugs. That's a little hint about my new book.  Coming in May 2011.  Just when you thought it was safe to go back in the garden.


  1. I was thinking the same things as @FightForKids. Is this GMO? If it is GMO, does it have the potential to taint other plants (as GMO soybeans do with non-GMO soybeans)

    What happens to any predators that eat bugs paralyzed in this fashion. What are the long term effects on the predators (good bugs, lizards, toads, birds).

    And finally does it paralyze only Japanese beetles or any bug that munches on it.

  2. Jumping to the worst suspicions, much? No, not GMO. Read the link to the USDA-ARS research Amy provided: “The poisoning effect of geranium flowers on beetles is not a new discovery; it has been reported in scientific papers dating back to the 1920s. But the phenomenon has not been studied in depth—how or why it happens—until recently, when Agricultural Research Service scientists in Ohio picked up where scientists left off more than half a century ago.”

  3. Are we talking real geraniums or the Pelargonium annual? I think it has to be the annual, because the (*^(*%^^*japanese beetles LOVE one type of the real geranium that I have. It ticks me off that the linked article didn’t even give the latin name. How do you make the cursed beetle eat the geranium leaves? They are like deer, each year they have a different favorite plant. Will this be a spray that can be applied? It is coming into beetle season. Soon my evenings will be spent with a bucket of soapy water hand picking and squishing and drowning and cursing. No wonder the neighbors don’t speak.

  4. They say the same thing about larkspur – it is supposed to kill Japanese Beetles. In my neck of the woods larkspur is often done blooming by the time the beetles show up, but one year they were both here at the same time. No dead beetles to be found. They didn’t eat the flowers, there was way too many other things blooming that they preferred.

  5. ugh… i hate japanese beetles!!! i’d always find them fornicating in the basil plants when i worked on a farm… nasty, nasty bugs. i can honestly say i hate them more than tomato hornworms.

  6. Yes, beki, it grosses me out too, that the are chewing and screwing simultaneously, sometimes in a threesome. UGH.

  7. As someone who has grown up with beetles, I question how this will be useful.

    If beetles were palatable, things would already be eating them. They are not hard to catch. They tend to cluster on their favorite plants in what appears to be a food coma, and they are not easily frightened. Since I don’t see things eating them now, I don’t see how they would eat them when they were fully paralyzed, instead of just naturally lazy.

  8. Dr. Lee Reich covered the topic recently here.

    …I decided to have a chat with Dr. Chris Ranger, the USDA entomologist in Ohio who has been watching beetles keel over following feasts on geranium. It’s a good thing I called because Dr. Ranger quickly pointed out that Japanese beetles won’t eat geraniums unless nothing else is available.

    The potential exists, however, for a new botanical-based pesticide.

  9. Nope… They’re not talking about real geraniums, but the related Pelargonium zonale. I have LOTS of real Geraniums (Geranium maculatum). So…I guess that they won’t kill any Japanese Beetles 🙁

    But they don’t get eaten by them either:)

  10. Count me as one who hates those Japanese beetles. They will be emerging soon.

    I’m also looking forward to reading Wicked Bugs. Insects are fascinating, in their own surprising, creepy way.

  11. Wicked Bugs ? Sounds like another awesome book. Looking forward to learning why I should fear the smallest residents of my garden.

  12. Interesting…

    Tonight, I saw the first JBs on my roses. I had my organic rabbit repellent spray with me and gave the beetles a dousing…why not? The repellent (I Must Garden) doesn’t stink, but I’ve never smelled anything so bad as what happened when I sprayed those JBs! Do the JBs stink? My husband says I made them mad! LOL Hope so.

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