Sweat bees and cookoo bees - Ask Extension
I want to protect the sweat bee colonies from the cookoo bees. Is there any way to deter or accomplish this?
Knowledgebase
Sweat bees and cookoo bees #936352
Asked June 22, 2026, 12:03 PM EDT
I want to protect the sweat bee colonies from the cookoo bees. Is there any way to deter or accomplish this?
Larimer County Colorado
Expert Response
Hi Robin,
I know you also called the state CSU Extension Office. So I will respond here, but just know we've received both inquiries.
I reached out to a colleague who is a better bee expert and she said that there's not a lot of good measures that you can take to prevent this from happening. Once the sweat bees have laid their eggs, you can try putting mulch over the entrances to hide them from the cuckoo bees. Doing this also covers the bare soil they prefer to nest into. Unfortunately it's a "circle of life" situation.
The cuckoo bees will parasitize some of the eggs...and there will be a mix of cuckoo and sweat bee hatch. Cuckoos do pollinate some, but not as well as the sweat bees.
I know you also called the state CSU Extension Office. So I will respond here, but just know we've received both inquiries.
I reached out to a colleague who is a better bee expert and she said that there's not a lot of good measures that you can take to prevent this from happening. Once the sweat bees have laid their eggs, you can try putting mulch over the entrances to hide them from the cuckoo bees. Doing this also covers the bare soil they prefer to nest into. Unfortunately it's a "circle of life" situation.
The cuckoo bees will parasitize some of the eggs...and there will be a mix of cuckoo and sweat bee hatch. Cuckoos do pollinate some, but not as well as the sweat bees.
Dr. O’Connor
Thank you for responding to my question about the sweat bees and cuckoo bees! I just love the sweat bees and enjoy watching them while I’m out working in my garden and yard.
Respectfully,
Robin Monajjem
