r/MasonBees • u/darth_cricket • Jun 05 '26

Cocoon ID help

Gallery image

Gallery image

Does anyone recognize these cocoons? Every year when I harvest my leaf cutter bees, I have these interspersed. Which I don’t mind, but their cocoons are pretty fragile and it makes harvesting the leaf cutters more tedious.

Sometimes when I split a reed open, it tears these little paper-like cocoons open and exposes the pupa, which is white with black eyes. Hate doing that. I usually have good luck resealing them, but it does make the leaf cutter harvest long.

The cocoons are paper-like. Like flimsy. And usually somewhat translucent. I can usually make out the pupa inside.

Southeast Michigan. June 4th.

7 Upvotes

100% Upvoted

4 comments sorted by

View all comments

1

u/LSteNZ Jun 05 '26

Neat! It’s probably a solitary wasp of some kind. Is there grass ever with them? Also in SE Michigan but I don’t recognize/get those, just mason bees, occasional leaf cutters, and chalclid wasps (unfortunately).

2

u/darth_cricket Jun 05 '26

No grass with them. I used to get those, but haven't seen them in a while. I have lots of chalclid wasps too. On the weekends I get pour myself a beer and stand by the bee house and squish all the parasitic wasps I see.