Not required, you can create your own if necesary but certainly useful if someone has already done it for you!.
I checked my copy of MPLAB and MPLABX and they both have the files you need included in them. I've copied them here for you anyway. These are the ones from the final release of MPLAB.
Thanks Brian. I have version 8.8 which actually doesn't seem to have files for many of the chips even though the project wizard lists the chip. Will update.