A Potter Wasp’s Guide to Child-rearing

During the last Total Fire Ban day I was looking out of the bedroom window at the distant heat haze when an Orange Potter Wasp (Eumenes latreilli) commenced building its nest on the ledge outside. As it was 40+ degrees Celsius outside, watching the wasp’s efforts from the relatively cooler space inside my house seemed a cruisey way for me to spend the afternoon. It struck me that Potter Wasps have whittled child-rearing down to four simple steps, and have it all done and dusted within an afternoon.

Step 1. Build the nursery.
Over a two and a half hour period the wasp flew several times to the nearest mud source (probably our dam) and came back each time with a ball of mud clutched between the front pair of legs (pictured left). On nearing the nest it gripped the rim of the nest with its middle pair of legs to settle and using its jaws proceeded to mould the mud into shape, extending the size of the nursery.

Step 2. Lay eggs in nursery
After the eleventh delivery of mud the nest was complete apart from a small opening at the front. The wasp then took about two minutes to lay egg/s in the structure (pictured right).

Step 3. Stock nursery with food.
Potter Wasps use paralysed butterfly or moth caterpillars as the food of choice for the larvae when they hatch. During the next hour, three caterpillars were placed in the nest (pictured below).

Step 4. Seal nursery with mud and start again.
Unfortunately this step never happened. After three caterpillars had been placed into the nest the wasp left and never returned. I suspected the hunter had become the hunted. Then three days later the nest was sealed. I don’t know whether the same wasp came back to finish the job or whether another Potter Wasp opportunistically did. Maybe it was a Cuckoo Wasp. I’ll have to watch what emerges.

Another reason to sit inside this summer looking out the window!