Bumble bee larvae on front porch - Ask Extension
Hello, I have a bird house at my front porch that contained old nesting materials. It has been taken over by rust banded bumble bees. My question is: ...
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Bumble bee larvae on front porch #869355
Asked May 20, 2024, 6:53 PM EDT
Hello, I have a bird house at my front porch that contained old nesting materials. It has been taken over by rust banded bumble bees. My question is: the larvae from the bees has been coming out of the bird house and landing on the porch. Is this normal / typical? Are they falling out?? Is this part of routine behavior? Thank you!
Multnomah County Oregon
Expert Response
Hi Alica,
Can you send me an image of the larvae that are falling? This is unusual.
But, I thought it would be helpful to put a name to a face. I think you have the black tailed bumble bee, Bombus melanopygus, which is one of our few species that nests above ground. Here is a nice key to the orange banded bumble bees of Washington as a resource:
https://washingtonbumblebees.org/bumbles-with-some-red-in-middle/
I ALWAYS get emails this time of the year about these bees in birds nests, and then the emails stop coming a month later. Here is why I think that is the case. These are among our earliest nesting bumble bees, with queens establishing nests in February. The colonies are starting to become visibly large. They will naturally collapse in a few weeks, with the nests producing new queens that will disperse across the landscape preparing for next year. I suspect your colony is nearing peak size at this junction.
Best,
Andony
Can you send me an image of the larvae that are falling? This is unusual.
But, I thought it would be helpful to put a name to a face. I think you have the black tailed bumble bee, Bombus melanopygus, which is one of our few species that nests above ground. Here is a nice key to the orange banded bumble bees of Washington as a resource:
https://washingtonbumblebees.org/bumbles-with-some-red-in-middle/
I ALWAYS get emails this time of the year about these bees in birds nests, and then the emails stop coming a month later. Here is why I think that is the case. These are among our earliest nesting bumble bees, with queens establishing nests in February. The colonies are starting to become visibly large. They will naturally collapse in a few weeks, with the nests producing new queens that will disperse across the landscape preparing for next year. I suspect your colony is nearing peak size at this junction.
Best,
Andony
Thanks for the info.
As I type this there are 5 larvae that I see on the ground. They’re just sort of wiggling along. I hope the picture shows them clearly enough.
Alicia
Thanks, Alicia,
I am not sure what species these larvae are, but they are not bumble bee larvae. My guess is that it is a beetle or fly larva - there are many species that are associated with bumble bee colonies, some are parasites or predators, others are just scavenging on the inevitable debris cast off from the nest. They may be exiting the nest to pupate in the ground.
Best,
Andony
I am not sure what species these larvae are, but they are not bumble bee larvae. My guess is that it is a beetle or fly larva - there are many species that are associated with bumble bee colonies, some are parasites or predators, others are just scavenging on the inevitable debris cast off from the nest. They may be exiting the nest to pupate in the ground.
Best,
Andony
