Mud Wasp Nest from Australia

Subject: What’s this?
Location: Inner west sydney Australia
January 19, 2013 7:17 pm
We had a cover over out outdoor treadmill that wasn’t used for a while. When we took it off these are attached to the smooth plastic. I’m hoping they are moth/ butterfly cocoons rather than something more sinister. We are in inner west sydney NSW its the middle of summer and we have had some record breaking hot spells. Any info is hugely appreciated before we decide if to get rid of them. They are a mud brown colour and all slightly different sizes
Signature: Mike bradley

Mud Wasp Nest

Hi Mike,
The reason this looks a mud brown color is that it is a nest made of mud.  Mud Wasps construct nest like this all over the world and the female wasp provisions the nest with prey that serves as food for the wasp larvae.  Prey is often spider or caterpillars, and each species of Mud Wasp has its own diet.  Mud Wasps are solitary wasps and they are not aggressive.  We would urge you to allow these chambers to hatch naturally.  Each chamber serves as a nursery for a single wasp larva, so if all proceeds well, four wasps will eventually emerge.  We believe your nest is that of a Mud Dauber, possibly
Sceliphron formosum, which provisions its nest with spidersYou can get additional information and see some photos on the Brisbane Insect website which states:  “The wasps build mud cells in sheltered locations. If the cell is opened, you will find a wasp larva, together with some spiders which are the larva’s food. Those spiders are collected by the mother wasp.”

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