Let’s say you’ve noticed some strange, round holes in your plant leaves.
These circular holes have fairly smooth edges. (They aren’t jagged.)
It almost looks like someone took an office hole punch and punched circles along the edges of your leaves.
What’s making these round holes in your plant leaves?
Is it Japanese beetles??
Nope, Japanese beetle damage looks different.
It’s more likely you have leafcutter bees—a native bee and beneficial insect in Colorado. They’re important pollinators for wildflowers and some fruits and veggies.
(Cool!)
Leafcutter bees aren’t eating your leaves.
Rather, they’re cutting circular pieces to use in the nests they’re building for their babies. They’ll insert the leaf piece into a hollow tunnel, along with nectar and pollen. Then, the mama bee lays an egg and seals it off.
Her bee nursery is ready to go.
What plants do leafcutter bees like?
Almost any plant with broad, thin leaves is fair game.
In my garden, the leafcutter bees love cutting round holes in the leaves of my lilac bushes and a flower plant called Golden Candles (Thermopsis lupinoides). In Colorado, leafcutter bees are often fond of rose bushes too.
I’ve noticed circles and semi-circles that are dime size, but many of the holes are smaller.
So, should you be worried about the round holes in your leaves?
Typically, no.
The damage is only aesthetic.
Insecticides will not prevent the bees from cutting holes, according to the Colorado State University (CSU) Extension. So, save yourself money and a trip to the hardware store. Skip the insect sprays and powders.
(This will keep your garden ecosystem healthier too.)
In most cases, you don’t need to do anything…
Except maybe point out the leaves to your friends, so they can see that your garden is a favorite among pollinators.
If you have a perennial—a flower plant that comes back every year—that the leafcutter bees have become REALLY fond of, the CSU Extension suggests covering the plant with loose netting or cheese cloth to deter the bees from making holes.
Put up the netting when you first notice damage.
Related topics that may interest you:
- Helpful fact sheets on leafcutter bees from the CSU Extension and the University of Florida Extension
- Why bees and butterflies are like puppies and kittens
- Planting a perennial garden in Colorado? 5 counter-intuitive tips
