Cuckoo Bee: All You Need to Know in a Nutshell

Cuckoo bees are fascinating insects that have a unique lifestyle in the world of bees. They are known as “cleptoparasites,” which means they lay their eggs in the nests of other bees, stealing their host’s pollen provisions for their own offspring. This behavior gives them their name, as it is similar to the way cuckoo birds lay their eggs in other birds’ nests.

There are over 3,000 species of cuckoo bees worldwide, belonging to various genera. These bees exhibit diverse physical appearances, depending on their host bee species. For instance, some cuckoo bees mimic their host’s colors, while others look completely different. Overall, cuckoo bees tend to be hairless compared to their pollen-collecting counterparts, as they do not need pollen-carrying hairs.

In general, cuckoo bees play a lesser-known role in the ecosystem. While they might not be directly involved in pollination like other bees, their presence can be an indicator of a healthy bee population. Plus, their unique behavior showcases the diverse ways that different bee species have evolved to survive and reproduce.

Cuckoo Bee Overview

Species and Identification

Cuckoo bees belong to the Nomada genus and are characterized by their wasp-like appearance. They have a slender body, with yellow-to-orange markings. Some species include:

  • Nomada fervida
  • Perdita minima
  • Thyreus species

Their main distinguishing features are:

  • Long, slender body
  • Yellow-to-orange markings
  • Absence of branched hairs and scopa (pollen carrying apparatus)

Cuckoo bees can be difficult to identify, as they mimic other bee species, like the Thyreus genus.

Cuckoo Bees Vs Bumblebees

Feature Cuckoo Bee Bumblebee
Body Shape Long, slender Plump, robust
Markings Yellow-to-orange Yellow, black, white
Pollen Carrying No scopa Presence of scopa

Cuckoo bees and bumblebees both belong to the larger group of native bees. However, they differ in their appearance and behavior. Cuckoo bees have a more wasp-like look, while bumblebees are rounder and fuzzier.

Parasitic Behavior

Cuckoo bees are known for their parasitic behavior, which involves laying their eggs in the nests of other bee species. They tend to target solitary bees. Once hatched, the cuckoo bee larvae consume the host’s pollen provisions and may even devour the host larvae.

Some key points about cuckoo bee parasitism include:

  • Target solitary bee nests
  • Lay eggs in host’s nests
  • Cuckoo bee larvae consume host’s pollen provisions and larvae

This behavior allows cuckoo bees to avoid the effort of collecting pollen and building their own nests, making them unique among bee species.

Life Cycle and Nesting

Host Bee Nests

Cuckoo bees are known for their brood parasitism, which means they lay their eggs in host bee nests. They target nests of other bee species, such as bumblebees and solitary bees.

Examples of host bee nests:

  • Bumblebee nests: usually found in abandoned rodent burrows
  • Solitary bee nests: often constructed in hollow stems or sandy soils

Eggs and Larval Development

After finding a host nest, cuckoo bees lay their eggs inside. The egg, larva, pupa, and adult stages come in order. Cuckoo bee larvae have distinctive traits:

  • Prognathous: forward-facing jaws
  • Long, sickle-shaped mandibles

These features allow cuckoo bee larvae to consume host bee eggs and larvae for nourishment.

Host Bee Interactions

Cuckoo bees depend on host bees for survival. Some ways they interact include:

  • Taking advantage of host bee-provided resources, like pollen and nectar
  • Mimicking host bee appearance to avoid detection
  • Exploiting host bee care for their offspring
Host Bee Cuckoo Bee
Builds nests Lays eggs in host bee nests
Gathers food Leverages host bee-provided food
Cares for brood Host bee care benefits cuckoo bee offspring

Cuckoo bees are fascinating creatures that showcase the diversity and complexity of bee species interactions. By understanding their life cycle and nesting habits, we can better appreciate their role in the ecosystem.

Physical Adaptations

Reduced Body Hair

Cuckoo bees exhibit a notable physical adaptation: their reduced body hair. This is significant because:

  • Less hair makes them sleeker in appearance compared to regular bees
  • It enables them to infiltrate host nests with less resistance

Abdomen and Exoskeleton

The abdomen and exoskeleton of cuckoo bees have specific adaptations as well. Some key features include:

  • A sturdy exoskeleton for protection against attacks from host bees
  • A pointed abdomen, which can be used as a weapon in confrontations
  • No sting, which helps to avoid causing alarm in host species when infiltrating nests

Wings and Mandibles

Cuckoo bees also have distinct adaptations in their wings and mandibles. Notable characteristics are:

  • Stronger wings for swift movements and evasion when necessary
  • Larger and more robust mandibles for defense and manipulating host brood

Comparison of Cuckoo Bees and Regular Bees:

Feature Cuckoo Bees Regular Bees
Body Hair Reduced Abundant
Sting Absent Present (in most bees)
Abdomen Shape Pointed Rounded
Mandibles Larger and Robust Smaller and Less Robust
Exoskeleton Stronger Regular Strength
Wings Stronger Regular Strength

In conclusion, cuckoo bees display various physical adaptations that enable them to successfully infiltrate host nests and survive in their unique parasitic lifestyle.

Ecological Impact

Cuckoo Bees as Pollinators

Cuckoo bees, including species like the variable cuckoo bumble bee, are unique in their ecological role as they do not collect or store pollen like other bees. Instead, they rely on host species for their survival. While they might not be primary pollinators, their interactions with host species can contribute to the overall pollination process.

  • Cuckoo bees:
    • Do not collect or store pollen
    • Rely on host species

Cuckoo Bee Predators

Predators of cuckoo bees may include wasps, flies, and other insectivores like birds and bats. By acting as prey to these predators, the cuckoo bee population contributes to a balanced ecosystem and supports the survival of various other species.

Effects on Ecosystem and Biodiversity

Cuckoo bees, such as the Suckley’s cuckoo bumble bee, act as social parasites, invading the nests of other bee species and taking control. Their presence affects the behavior, distribution, and abundance of host bee populations. In turn, this can potentially impact plant pollination and fruit production.

However, their kleptoparasitic behavior brings diversity to the ecosystem and can help maintain a balance between different pollinator species.

Comparison of Cuckoo Bees and Honey Bees

Feature Cuckoo Bees Honey Bees
Pollen Collection Do not collect or store pollen Collect and store pollen
Social Behavior Social parasites Live in colonies
Role in Ecosystem Kleptoparasitism Primary pollinators

In conclusion, the role of cuckoo bees in ecosystems can be complex, and their behaviors greatly differ from other bees. While their impact on pollination and other ecological processes might not be as significant as honey bees, they still contribute to overall biodiversity, and their presence helps maintain a balanced ecosystem.

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Cuckoo Bee, NOT Ant Queen Kidnapping Wasp


Subject: Is This a Yellow Jacket?
Location: Tacoma, WA
June 7, 2016 5:07 pm
Due to a bee hive having been completely destroyed last Summer, I have been more attentive to Yellow Jackets this Spring. This one I am having trouble finding information on. The 3 pictures attached are all I”m able to get, as they seldom touch down long enough to focus on. Generally, they move around constantly. So far I have only seen them in the Thyme. They look and fly like Yellow Jackets, but they are tiny, less than half the size, maybe 8-10mm. It also has a large, light colored eye more like a sweat bee.
Signature: Ralph

Ant Queen Kidnapping Wasp
Cuckoo Bee

Dear Ralph,
We are very excited about your submission.  This is NOT a Yellowjacket.  If our identification is correct, this is a new species and a new subcategory for our site, but it also has one of the best names we have ever heard for an insect.  Based on this BugGuide submission, we believe this is an Ant Queen Kidnapping Wasp,
Aphilanthops hispidus.  Of the genus, BugGuide states:  “Nest in ground” and “nests provisioned with winged queen ants.”  There are not many images on the internet, but we did locate this image of a mounted specimen on EncicloVida.  Of a related species in the same genus, BugGuide states:  “Nests are dug in sandy, pebbly soil to a depth of 45 cm. Sometimes form aggregate colonies of 25 to 60 females, especially on sandy slopes with entrances as close as 2 cm apart. Winged queen ants are captured when wandering on the ground, stung and carried to nests with ant antenna between wasp mandibles and rest of body held between the legs. In the nest tunnel, wings are removed and ants are stored near entrance in a cell until individual egg cells are dug. Storage is necessary due to the short flight cycle of winged ants. Females possibly can lay only one egg per day (Evans, 1962). Usually 2 to 3 ants are used in each cell. One generation per year.”  We are postdating your submission to go live tomorrow as we are preparing for a holiday away from the office.

Ant Queen Kidnapping Wasp
Cuckoo Bee

UPDATE:  June 17, 2016 Eric Eaton provides a correction
Hi, Daniel:
Great images, but they depict a cuckoo bee, Nomada sp., not a wasp.

Ant Queen Kidnapping Wasp
Cuckoo Bee, NOT Ant Queen Kidnapping Wasp

Letter 2 – Cuckoo Bee, we believe


Subject: stripes and red legs
Location: coastal South Carolina USA
June 4, 2017 7:20 pm
Hi Bugman!
Thanks for the great website!
I took this photo of a cutie-pie with stripes and red legs on Memorial Day in my bed of native plants from coastal South Carolina. The primary flowers blooming nearby were Stokes aster and Lanceleaf coreopsis. I don’t recall ever seeing one before; could you please help identify it?
Thank you!
Warmest regards,
Signature: DJ

Cuckoo Bee

Dear DJ,
After some research, we believe this is a Cuckoo Bee in the subfamily Nomadinae.  We found several images on BugGuide that look similar.  Do you have any images of the front of the insect?  This BugGuide image of
Epeolus autumnalis, this BugGuide image of Epeolus scutellaris, and this BugGuide image of Triepeolus lunatus all look similar to your individual.  According to BugGuide:  “All lack a pollen-transporting apparatus and many are strikingly wasp-like in appearance. The apex of the metasoma of females is modified for placing their eggs within host nests” and “All are parasites in the nests of other bees. They enter the nests of their hosts when the host is absent and lay their eggs into the wall of the cell.  Females produce many more eggs than their hosts and these are very small.”  We are post-dating your submission to go live to our site later in the month when our editorial staff is away on holiday.

Dear Daniel,
Thank you very much! Yes! You have solved the mystery!
Unfortunately the photo I submitted was the only one I took (lesson learned for next time), but after receiving your message I reviewed images I found searching the Internet for “Epeolus” and I’ve located a few with red legs, matching markings, and the same antennae and they appear to match-up very nicely with my photo.
It is especially interesting the specimen is a bee as my husband and I have a hive in our backyard we manage as urban/hobby beekeepers here in Charleston.  I have been reading and studying to try to learn as much as possible to help promote the use of native plants to sustain bees and all native pollinators. Recently I accepted an invitation to make a presentation about the topic and I’ve been keeping notes about special characteristics or unusual behaviors of various bees that I learned from reading “Attracting Native Pollinators” guide by The Xerces Society.  Since some of the folks attending are also National Audubon Society members, I planned to mention the similar behavior the cuckoo bee has to the cuckoo bird; however, I am just elated that now I can include a photo of one from my own yard!
I really appreciate your kindness taking time researching/responding to my question and I’m delighted you and your colleagues will be taking a well deserved holiday soon. Enjoy!
Thanks a buzz-zillion! : )
All my best,
DJ/Debbie Fisher

Letter 3 – Neon Cuckoo Bee from Australia


Subject: Black and Blue insect
Location: Canberra Botanic gardens
January 29, 2013 11:00 pm
Was gathering pollen the same as bee’s
Signature: not signed

Neon Cuckoo Bee

This appears to be a Neon Cuckoo Bee, Thyreus nitidulus, which we identified on the Brisbane Insect website.  According the the Brisbane Insect website:  “The Neon Cuckoo Bee are cleptoparasitic in the nest of Amegilla sp.. Neon Cuckoo Bee female does not make its own nest. It lays egg in the nest of Blue-banded bee. Female places an egg in a partially completed brood cell. After the blue-banded bee finishes provision and seals the brood cell, the cuckoo bee egg hatches into larvae and feeds on the provisions stored by Blue-banded bee. ”  This is a new species for our site.

Thank you Daniel. Only wish the pic came out better.

Letter 4 – Cuckoo Leafcutter Bee


Subject: cuckoo bee
Location: courtice ontario
August 8, 2015 12:59 pm
Hi again
sending this pic but I am pretty sure it is a cuckoo bee.
Signature: terri

Cuckoo Bee
Cuckoo Leafcutter Bee

Hi Terri,
Thanks for sending us more wonderful images, and using our standard form makes things so much easier for us.  We went on BugGuide to verify your identification, and though we tried, we could not find any images that look quite like your Cuckoo Bee.  The position it is resting in is quite different from anything on we found, though the images of the members of the Tribe Epeolini on BugGuide are the closest visual match to your individual.  We wonder if perhaps your images were taken early in the morning after the Cuckoo Bee had spent the night inactive, and that the heat of the day had still not warmed it to the point of activity.  If possible, can you please cite the source that led to your original identification along with any relevant links?

Cuckoo Bee
Cuckoo Leafcutter Bee

Hi Daniel
I did not really know for sure a friend of mine who takes photos of insects as well said it was a cuckoo bee and I took his word for it.
It was very early in the morning the tend to sleep at the top of grass or sticks and they wake up slowly so they are easy to photograph.
There were here the month of june and july but I have not found any lately in the month of august.
I was lucky I could take the photo wait for the sun to rise enough until they become active. They clean themselves and take off  to start the  day.
Thanks so much Terri
I am sending a few more photos here so you can see how he hangs upright on the twig

Cuckoo Leafcutter Bee
Cuckoo Leafcutter Bee

Eric Eaton Confirms
Wow!  That is a female cuckoo leafcutter bee, Coelioxys sp.  Can’t tell more because I’m not sure how to identify these to species, or if it is even possible from images alone.  They are cleptoparasites of real leafcutter bees.
author, Kaufman Field Guide to Insects of North America

Cuckoo Leafcutter Bee
Cuckoo Leafcutter Bee


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts

5 thoughts on “Cuckoo Bee: All You Need to Know in a Nutshell”

  1. Thank you for your quick response and identification, and somewhat creepy description of the little wasp I found in my garden. I’ve watched them in the thyme the last couple days doing what I assume is their mating ritual. As many as 8 wasps spend their time hovering above the thyme. A couple of visibly smaller wasps that seem to have a bit more iridescent yellow, also hover. When a larger wasp lands and is on the thyme more than a couple seconds, the smaller wasp pounces on it. There’s a scuffle, and both take of in different directions.

    I also have been able to get some better pictures of them, which I will be happy to share if you want them.

    Thanks again.

  2. Thank you for your quick response and identification, and somewhat creepy description of the little wasp I found in my garden. I’ve watched them in the thyme the last couple days doing what I assume is their mating ritual. As many as 8 wasps spend their time hovering above the thyme. A couple of visibly smaller wasps that seem to have a bit more iridescent yellow, also hover. When a larger wasp lands and is on the thyme more than a couple seconds, the smaller wasp pounces on it. There’s a scuffle, and both take of in different directions.

    I also have been able to get some better pictures of them, which I will be happy to share if you want them.

    Thanks again.


Leave a Comment