Friday, June 4, 2010

Leaf Cutter Bees Are Picky About Beans

A few years ago, I learned about the leaf cutter bees and how they make like a jigsaw and cut nearly perfect circles out of the leaves of some garden plants.I happened to be in the right place at the right time and saw one land, quickly cut a piece of leaf and fly off with it.  It was the coolest thing ever, I have to say.

I did some some research and found out what they were.
They don't eat the pieces of leaves they cut; they use them to line their nests.

Leaf cutter bees are solitary bees, slightly smaller than a honeybee, and only sting when handled. Their sting is much less painful than that of a honeybee, to which I can personally testify.  I'm allergic to bee stings, but being stung by a leaf cutter bee only gives me a slight bump.  I get far more reaction to a mosquito bite than these stings.  Oh, it hurts, to be sure, but only for a minute or so.

They use the leaves in their nests, which they make in rotting wood or the stems of soft wood plants.  They rarely hurt the plants where they make their nests, because they burrow past the cambium layer, further inside. My personal feeling about them is to leave them alone and accept the holey leaves, because they are important pollinators.

Beans - No holes

This year, I noticed they're picking on my green beans! Or maybe it's the yellow wax ones they prefer.  We planted our beans in a hurry a few weeks ago, because we wanted to get them in before an approaching rainstorm. There are three different varieties and in our hurry, I didn't label the rows.  I figure we'll know what they are when they start producing the beans.

Beans - With holes

The leaf cutters have done a number on just one row of beans and have left the other rows alone! They seem to like the lighter foliage on one of the rows, which I suspect are the yellow wax beans, given to me by my Soil Sister, Lisa, from Get in the Garden. Time will tell!

Check out this 7-second YouTube video that someone shot of a leaf cutter bee in action!

Photo of leaf cutter bee from Maggie Frankum via


Anonymous said...

I was introduced to the leaf cutter bee last summer when I noticed the same holes in my pepper plants. :) They are fascinating to watch.

Lisa at Greenbow said...

I have seen the results of such an attack on some of my plants before. I thought it was some kind of caterpillar.I will watch for bees now.

Nutty Gnome said...

We don't have leaf cutter bees over here, so I loved watching the video! I wouldn't mind a few holes in my plants if I got to watch the bees on a regular basis:)

Lisa said...

I'm curious! Did you plant other heirloom beans besides the seeds from me?! Maybe the bees know the difference!

garden girl said...

Hmmm. . . maybe that's what's eating holes in our pepper foliage.

F Cameron said...

Interesting. Do they eat zinnias? I was blaming a grasshopper, but now, I'm wondering about those leaf holes!

Anonymous said...

I think this is what makes holes in my alchemilla leaves. They're decorative in a way and nothing can kill my alchemilla hehe. I didn't know it was a specialized bee that did it. Fascinating. Thanks for the biology lesson and the video; I've never seen the bees at work. Jane

teresa said...

I had no idea about these bees. I will pay much closer attention to the holes in myleaves from now on and maybe I will catch one in action. Thanks for the info.

Garden Lily said...

So cool! I hope I'll be able to see one in action some day.

Garden Lily said...

Yesterday when I was weeding between my strawberry plants, I spotted a bee on the ground holding a circular piece of leaf, just before he flew away. Thanks to your post, I recognized this as a leaf cutter bee! Thanks so much! So now I'll really be watching to actually see one "in action". So cool.

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