Robins Pin-cushion. Copyright 2009 Peter Drury Two pin-cushions in the eary stage of formation. This Gall is caused by the Diplolepis rosae Gall wasp injecting chemicals in the leaf bud of a rose. The resulting structure provides protection for the wasp larvae from predators and also climate. The young wasps emerge in the spring. - "Imageinuk Photography - Peter Drury"