Arbanitis robertsi is a species of tube-dwelling spider in the family Idiopidae found in and near rainforests in New South Wales and Queensland, Australia.

A mid to large sized spider which builds a tube of web that extends from the burrow.

Thousands of these tubes were recorded by Sid Jackson in November 1922 at the south eastern end of Wallis Lake.

The vibration of crawling insects on the tube is said to alert the spider to potential prey.

[4][5] Prey is caught at the opening of the tube, including moths, beetles and other crawling insects.