They are not eating the leaves, they are lining nests with them, so unless you cake some sort of toxic powder onto the plant continually, you can't kill them.

They almost never kill a plant, even though they may leave some of the newer leaves looking like Swiss cheese. It goes in cycles, depending on the nesting activity, so they may not come back for a while.

Also, they are an important native pollinator species.

The bees can actually kill the plant. I have had it done before. IF they chew too may leaves the plant cannot have proper photosynthesis.... Plus the larva will bore into the cane. If it was just on looks, I wouldn't care. But I refuse to loose another rose because of this bee. So what is the name of the powder that you are talking about... I would be happy to try it.

Thanks

I think that what lazygardener was saying is that there isn't anything you can do to kill them......they are not eating (ingesting) the leaves.

You might try neem oil. One of its properties is that it acts as an anti-feedant.......thus, it might repel the bees from your rose leaves. I think that these bees only bore into the pith and do not drill or girdle the cambium. Don't leave any cut, hollow stems exposed.

As always, read and follow the directions carefully, and use the product responsibly.

I am not sure that I can do the neem oil. I just read that it needs to be below 90 degrees and humidity should be in the 45 to 65 percent range. In South Florida that is hard to do... maybe in late October, but what can I do now. Do you have any other suggestions. Any help is appreciated.
Thanks.

Netting? You know, the mesh kind of row cover that veggie gardeners use. Yeah, the bush would look ugly for a couple of weeks until the bees turned their attentions elsewhere.

Here is what the Colorado State University Extension says about controlling leaf cutter bees:

Insecticides are ineffective for preventing leaf cutting. The only known control of leaf injuries is to cover susceptible plants with cheesecloth or other loose netting during periods when leafcutter bees are most active.

You might figure out when they are active in your area - here it is only for a few weeks in the Spring.

So, it looks as if Cecily has the correct idea. The CSU also said that to prevent them from boring (they only do this on LARGE canes) into canes, you can put glue or something like that on the canes when you cut them.

Jackie

They are pollinators. And they are only active for a short time. Cover your plant with cheesecloth, and leave the bees alone. We don't need to kill everything that flies or crawls.

When their active period is over, remove the cheesecloth. No harm done.

Personally, I find them fascinating, and love to see them work.

(Their larvae, btw, eat aphids.)

Jeri

I've had leaf cutters put holes all over my roses and I've never had a rose die because of them. As Jeri said, they only do it for a short time and they're gone. They are important pollinators and preditors so don't kill them, please. Do not remove any of the cut leaves. As long as they remain green they are still feeding the plant. If the leaf is too damamged it will yellow and fall off on it's own. As the plant grows new leaves will come along and you'll never even know they were there.

I think you will find that now that your Quietness is out in the sun it will do much better for you all around. It is a big rose even for me in my cold climate but it does not seem to mind hard pruning when necessary. I had to cut mine to less than six inches high this spring and it is about 4 feet tall and wide again and blooming very well.

As far as boring into the canes, it was Dr. Tommy Cairns who told me not to worry about it, as those larvae ate aphids. Sometimes, it is wisest to let nature take her course. We humans DON'T always know best.

I have, since then, followed Dr. Cairns advice and done better for it.

Jeri

I appreciate everybody's response. I hope to get some cheese cloth this weekend. Maybe Joann's Fabric?
I lost two roses about 10 years ago from the bees. Their larva kept eating in the canes until there was nothing left. I will try the glue and hopefully that will work.
My Quietness was already 3 1/2 feet tall just from upgrading in the pots. I can hardly wait till she takes off. She has the best smell.
Can anyone also tell how to do the cheesecloth..... Can it touch the leaves... What about the air circulation. I am not sure if I can build something that will keep it from touching the leaves, I live on the intracostal and get really heavy winds and gales.... But up to any suggestions.

Again. Thanks

I don't know if Joanns would have it. I always get my cheesecloth at Meijers in the KITCHEN gadgets, like mashers, peelers, spoons and thermometers, etc., section. It's often used to strain things in cooking. Any place that has kitcheny stuff should have packages of cheesecloth. The packages are deceiving. Once you open it all up there's a ton of it in there.

If you lost roses from borers it probably wasn't the leaf cutters but something else. You only need to glue cuts on canes that are thicker than a pencil. They don't bore into the real thin canes.

Yes, the cheesecloth can touch the leaves. It's very loose woven so air will circulate just fine through it. Just drape it over and around the bush gently. My only concern would be if it rains. The cloth will absorb water and become heavy and could break some smaller canes. You might want to put some stakes under it to carry the weight if it rains. You should only have to do this for a couple of weeks at most because once they've mated, built a nest and laid their eggs they will stop cutting the leaves. As Jeri said, the leaves are only used for nesting materials.

I agree with seil - cheesecloth is very easy to find. My regular grocery store has it in the same section as tin foil, plastic wrap, parchment paper, etc. Just make sure to unfold it all the way - it comes all folded up.

Jackie

Leaf-cutters are not the same bees as the ones that nest in the cut cane ends. The latter is the small carpenter bee. Leaf cutters nest in the ground, usually under an object such as a rock, flagstone, or pavement edge.

Since there is something about the foliage of particular roses that attracts them, it seems likely that certain substances applied to the upper leaf surface ought to repel them by changing the texture or taste / smell. Unfortunately we don't know what those are. I was going to suggest oil, but you might try Wilt Pruf or another anti-transpirant film. Spray in the morning when plant is well hydrated and on the upper leaf surface only.

I have LCBs in the roses every year, and, like others, have never seen a serious problem. However, I take the OPs word for it.

As far as boring into the canes, it was Dr. Tommy Cairns who told me not to worry about it, as those larvae ate aphids. Sometimes, it is wisest to let nature take her course. We humans DON'T always know best.

I have, since then, followed Dr. Cairns advice and done better for it.

Jeri

Weird! My earlier post repeated itself, a day later!

Jeri

This post was edited by jerijen on Wed, Sep 24, 14 at 16:30

TULLE is the greatest fabric for covering plants to protect them from pests. You can find inexpensive tulle in any craft or fabric store, or on line. It's available in a variety of widths and usually sold by the yard.

Bees make your food possible. Without bees there would be no nuts, apples, stone fruits. Please don't kill the bees!

Go to any fabric store and get Tulle, as rhizo suggests. It's really cheap and quite sturdy. Hold it down with bricks or rocks.

Tulle sounds like a GREAT idea!