Bullant steals Wasp's Spider

Back when I lived in Sydney I enjoyed taking my camera to a particular high point on the Georges River just off Alfords Point Bridge Road. It gave me good views of the river and a great vantage point to watch The White Bellied Sea Eagles fly out to forage or return to their nest. There was a large rock not far from the edge where I could sit in the shade of gum trees and observe the river.

On this particular day the rock was already occupied by a wasp. It is a spider wasp and appears to be from the Tribe Pompilini.

On seeing me it stared but did not retreat. It was agitated but did not fly away. Instead it pranced around the rock, watching me. it was also interested in something in the middle of the 2 metre wide rock.

A closer look and to my excitement it had captured what looked like a leaf curl spider and had it in the middle of the rock. It was paralised and probably ready to be transported to a nest. These wasps sometimes catch the spider and then take it to a convenient sandy site where they will dig a burrow. The spider is then deposited in the burrow and an egg laid on the spider. When the egg hatches the larvae will eat the alive, but paralised spider before pupating.

This area is a cliff top full of sandstone rocks but also has sufficient sandy soil for trees to grow. Immediately next to the rock was a sandy path and it may have intended making a burrow here. I suspect my arrival meant it was unsure whether to leave the spider or take it with it. For the next couple of minutes it wandered around, flew off a short distance, returned and checked on the spider. It then continued prancing around.

I have a number of pictures taken at 2.07 showing her prancing around and then she decided to leave. Not seeing her I stepped forward and took a picture of the spider, also time stamped 2.07. I stepped back and there was movement on the other side of the rock. A Jack Jumper bullant (M. nigocincta) had made a beeline for the spider and was stinging it. Unfortunately that picture was out of focus as this was all happening quickly at 2.08 and I had a 400mm lens for bird photography. The next picture also taken at 2.08 shows the bullant dragging the hapless spider to the other side of the rock.

M Nigocincta nests in the ground but normally forages in the trees. They live mainly in the warmer areas north of Sydney. However, they are known to be present in Como and Heathcote in the southern suburbs of Sydney. Where this occurred is on the boundry of Illawong and Alfords Point, across the river and slightly west of Como.

It is probable this bullant was out foraging when it saw the spider and wasp. I did not see bullant until it grabbed the spider, however it may have waited at the far end of the rock watching. As soon as it had an opportunity it made a direct path to the spider, gave it a quick sting and then rapidly moved it to the far side of the rock. There it stopped, stung it repeatedly and then disappeared into the undergrowth. By the time I got to the other side of the rock it had disappeared.

A couple of minutes later the confused wasp reappeared flying, prancing, searching the rock for the spider. By then it was long gone. A fascinating encounter.