Q. Year after year something chews on my redbud tree. I never, ever have seen what does this. Any clue on what’s eating my tree? – M.C., Albuquerque
A. From the photo you submitted, I can see the near perfect half-moon surgical cuts that have been removed from the leaves of your redbud.
I’m confident that the “damage” is done by an insect called a leafcutter bee.
Other than aesthetics, please, rest assured the redbud is in no danger from this marvel of the insect world. Since the leafcutter is a bee, it’s a very important beneficial insect. Without bees, we’re in trouble.
Leafcutters are a very important pollinator of alfalfa, which is grown all along our river, so they need a bit of respect in my opinion.
The surgical removal of the half-moons is what these bees use to line their nests. Think of it as carpeting, before depositing an egg and some pollen, making a cell or room.
Then using a piece of leaf to make a door to protect the room, the leafcutter is off to find another cavity to carpet, doing the process the again and again. As each egg hatches, the larva feeds on the pollen then morphs into an adult, spending the winter sort of hibernating until spring when the new adult will chew its way through the leaves and emerge to pollinate more alfalfa.
It’s one of those circles of life things going on, except this circle is a very beneficial one. The leafcutter usually creates its home where it finds a cavity on wood. Wood fence rails, standing undisturbed piles of fire-wood, dead twigs on living trees, you name it, they’ll make any suitable cavity a place to make their nurseries.
No, they aren’t damaging new green wood (your redbud) to make their nurseries. Years ago while working at a nursery, we sold water spitting fountains. More times than I cared to count we had plugged up spouts on the unused fountains from leafcutters using that tube to make their nurseries. Once I understood what the heck was going on, it was heart-wrenching to have to remove the nests.
You say you’ve never seen what is doing the chewing and maybe not. The leafcutter looks a lot like a honeybee. About the same size and markings, except they are remarkably fuzzy underneath. That fuzz or hair is what makes them such great pollinators. As they tumble from bloom to bloom gathering some pollen to deposit with the egg in the leaf-lined cavity, they leave some pollen from other blooms behind and voilÃ, you have perfect flower pollination.
I worked with a gentleman who, while lazing on a chaise in his backyard one afternoon, close to a stand of rose bushes, actually heard the sawing and being absolutely amazed, watched as a leafcutter removed, with surgical precision, part of leaf and flew off with it to tend to its work. Such a blessing to hear and see that quiet noise of a bee at work.
You might notice a bit of raggedness where some of the half-moons have been removed, but that was probably caused by wind whipping the leaf. Since you can’t stop the wind and the leaves are still healthy green colored, no harm, no foul.
I’ll suggest and plead that you do nothing to prevent this remarkably beneficial insect from doing its job.
Q. For the last couple of years my tomato plants would “shut down” in July and August. You mentioned sustained daytime heat of over 90 degrees being perhaps the reason. We put up a canopy to keep the area a little cooler. The canopy is very tall. Do you think this will be bad for the plants? They get a little sunlight in the morning and early evening. – G.M., Albuquerque
A. When you say canopy do you mean like canvas tent material that will keep it fairly dark and shaded most of the day? If so, that might be not so good.
But being tall above them, like you say, there just might be enough light for the tomatoes to handle it. An advantage to the canopy being tall, and I think that’s a good thing, will be any available breezes moving through will keep the crop more comfortable.
But as soon as we come out of the wicked 90s I’d be gradually peeling the canopy back and allowing the tomatoes more sun.
You will want to watch your crop faithfully to make sure the morning and afternoon sun is enough and the plants are staying healthy until we get a break in the daytime high temperatures.
Good luck and Happy Diggin’ In.
Tracey Fitzgibbon is a certified nurseryman. Send garden-related questions to Digging In, Albuquerque Journal, 7777 Jefferson NE, Albuquerque, NM 87109, or to firstname.lastname@example.org.