japanese beetles

Well, it happened. I found dozens of Japanese beetles on the beans, and a few on my potatoes. From what I've observed, they are THE major pest to contend with in central Illinois. I was surprised because all of my friends and neighbors assured me that although they'd heard Japanese beetles were a problem, they'd never actually experienced them. I was not so lucky.

I had already been advised that the best way to get rid of them was to take a bucket of soapy water, set it under the plant, and shake the plant gently. Their instinct is to drop to the ground when the plant shakes, so they land in the bucket and quickly drown. I'll spare you the photo of the floating bugs:)

For me, this was only somewhat effective. Any that fell in the bucket were taken care of - they swim around for a while but they aren't able to get out, so they do die (perhaps cruel, I know). BUT the problem was that many of them would fly away rather than dropping. Perhaps the species is adapting, but I don't even think I was able to get half of them. Plus, it might work for certain types of plants but for the beans, it was logistically difficult to put the bucket in just the right spot.

What I found works best is to wear garden gloves, put one gloved hand underneath a leaf with a beetle on it (in case the beetle does drop off), then pick the beetles one by one and throw them into the bucket on the ground. This way they couldn't fly away, and I could tell if each individual was taken care of by the splash in the bucket. I did this three times a day and sometimes it took a half hour, because even doing this one by one some of them escaped (for example, there are often several on one leaf, and they fly away easily). I would do several loops around the bean bed, staying out there until I couldn't find any more. I found that they were the thickest at the hottest part of the day, which motivated me to get out to the garden at a time I would normally insist on staying inside. Also, I've noticed that the beetles are more likely to just drop off the leaf in the early morning before the sun is out, but later in the day they are more likely to fly away.

I was really panicked about this because they did an incredible amount of damage in a short period of time [see sample of demolished leaf photo below], and I found them soon before we were leaving on a week-long trip. When I returned, I was prepared to mourn the loss of my bean crop...


but to my surprise, the beans were living and continuing to grow. Yes, the beetles were still there and yes, they had continued to do damage in the week I was gone. But they didn't destroy any of the crops. They may have stunted their growth, and we will see what happens in the rest of the summer...but for now, I feel like my bean crop is safe. Hooray!

I would recommend taking care of the beetles the way I did. It can seem daunting to remove the beetles one by one, and perhaps gross - but as long as I had gloves on, it didn't bother me to pick up the beetles. And I could definitely tell each day that there were fewer beetles than there had been the day before at that time. Plus, beetles reproduce, so each beetle you get rid of is saving you exponential headache the following year. I would say about 1/3 of the beetles I find are engaged in reproductive activities when I snatch them and dunk them in the water. After they mate, they deposit eggs in the soil that turn into grubs, that turn into more beetles. Best to nip that in the bud!