Mud Dauber nest and pupa

[Pizzazz]

Gang

I removed the mud nest the dauber made by using an X-acto knife. I cut
gently along the base where it was attached to my stucco wall.

I went inside and observed the single pupa that was placed inside by
the female, and you can see the fine strand of silk to allow the pupa to
remain anchored to the inside. I can only assume the hole at the top of
the structure is for the pupa to be fed as it develops.

The photos of the nest have it siting on the side of small tweezers.


The mud nest measures 15mm wide at the base.
The pupa is 3mm long.

Notice the intricate shape of the mud housing! Amazing structure.

I have included a photo of the nest being made from a previous thread.

The wasp was taken with a Nikon 200mm macro lens.
The nest was taken with a micro nikkor 120mm lens on a 200mm bellows.
The pupa was taken with a Mitutoyo 7.5x objective attached to a Nikon
200mm macro lens.

[Lou Jost]

Excellent investigation! I suspect the larva might actually be a pupa-- it looks too featureless to be a larva.

[Pizzazz]

Lou

I should have been more diligent in my investigation. Thanks for the info; I made the changes.

[MarkSturtevant]

Hard to tell what that is. A wasp pupa will look like an adult wasp, with free legs and antennae, like this: http://bugguide.net/node/view/24634
Maybe a beautifully spun cocoon? Or a parasite?

[rjlittlefield]

Size is too small to be a cocoon of the nest-builder. Mike says 3mm long.

https://en.wikipedia.org/wiki/Potter_wasp notes that "Some species lay the egg in the opening of the cell, suspended from a thread of dried fluid."

3mm seems large for an egg, but Bugguide shows some similar examples where the egg is quoted as 2mm, so this seems a good possibility. See for example http://bugguide.net/node/view/658685/bgimage .

--Rik

[Lou Jost]

I should have investigated further, I had been thinking of diptera pupae...

[MarkSturtevant]

Given the size, etc., then it seems most likely the egg. A give-away is the grains of dirt for scale. I shoulda thought of that!