Mud-dauber Wasp, Sceliphron ?formosum

Adult wasps are a feature of every summer. I rarely get through the season without a sting or two, especially from paper wasps that often conceal their nests under leaves. The first warning that you’re too close is a painful sting.

But there are many different types of wasps and some of the more conspicuous are the larger, yellow and black mud-dauber wasps. These wasps have long legs and a very thin waist and are usually seen singly. Their flight is distinctive, as they dangle their long legs beneath them as they fly.

I’ve been watching a wasp construct a large nest, of many joined cells. She

The nest, made up of about 8 individual cells.

uses pellets of moist mud to build a cylindrical cell, fills the cell with paralyzed spiders and then lays an egg into the cell, before sealing the cell with more mud and starting the process again. For some reason she collected mud of two different types, giving the nest a mottled appearance.

There are 27 species of Sceliphron worldwide and several species here in Australia.

You can read a lot more about Sceliphron mud-dauber wasps on this Brisbane Insects page. Nest architecture can vary: the mud nest above has all the cells joined together, whereas some mud wasps build the cells separately.

Now, which wasps built these rather bizarre mud nests (below) under our house eves? Their trumpet-like protuberances, and detailed, textured construction are unusual and I haven’t been able to determine the ID of the builder- from observation or references. Can anyone help? Do the ‘trumpets’ have a purpose, or are they camouflage?

12 cm wide
7 cm wide
12 cm high