Round Holes in My Lilac Bushes?

Question:

Something is eating my lilacs as well as my flowering crabapple trees leaves. The holes are perfectly round, like a hole punch. This starts well after the flowers are gone. Can bees be the problem?

Hardiness Zone: 4b

Thanks,
Nancy from Darlington, ID

Answer:

If you've noticed bees around your crab apple tree and lilac bush, it's possible that you're seeing damage from leafcutter bees. They are similar in size to honey bees, but are darker in color with light bands on their abdomen.

Leafcutter bees cut perfectly round or semicircular holes into the leaves and use the fragments to line the cells in their nests. These bees are actually important pollinators of wild plants and should not be considered pests. They are generally not aggressive unless handled and their sting is much milder and much less painful than that of honey bees or yellow jackets.

Unlike their more social cousins the honey bees, leafcutter bees live a solitary life so you won't see big colonies or nests of them. The damage they do to leaves is only aesthetic and will not cause any lasting or permanent damage to your plants.

In some cases, these bees have even been semi-domesticated and used for agricultural purposes to help pollinate alfalfa crops. They have many natural predators so you are likely to see their populations and activity vary from year to year.

Ellen