During my move away from Google+ I came across a nifty utility by Brian O Donnell (rev138):
From the Readme:
Publishes RSS/Atom feeds to Diaspora*
This is a lightweight, customizable “bot” script to harvest RSS/Atom feeds and re-publish them to the Diaspora social network. It is posted here without warranty, for public use.
It’s quite helpful, I think, in that you don’t have to start from scratch by taking the last posts with you.