I found a vertical mud tube about the thickness of a pencil in my garden with a series of metallic green insects coming out of it. They came out when I pulled a weed but stopped when I stopped, as if the vibrations were scaring them out. I think they were bees, wasps, or flies. They were 1/2" long or a little longer and thin. Head, thorax, and abdomen were all shiny green, wings transparent. What are they?

I live near Philadelphia and it was in the upper 60s F today.

  • 1
    $\begingroup$ Did you happen to take a picture of them? $\endgroup$ Apr 24, 2018 at 5:35
  • $\begingroup$ alas, no camera available $\endgroup$ Apr 25, 2018 at 15:33

1 Answer 1


Mud tube, metallic green, bee-like - sounds like a mason bee to me.

There are several metallic green mason bees (Osmia spp.). As Wikipedia explains:

Mason bees are named for their habit of using mud or other “masonry” products in constructing their nests, which are made in naturally occurring gaps such as between cracks in stones or other small dark cavities; when available some species preferentially use hollow stems or holes in wood made by wood-boring insects.

One example here:

enter image description here Photos at http://www.laspilitas.com/insects/megachilidae/osmia-mason-bee.html


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .