No, sudo isn't needed when using "pacman -Q".  The "-Q" option simply queries the package database.

sudo is only needed when installing, upgrading or removing packages.  Or when updating the package database.

(Also, I removed using sudo from two paclocs and paclist.)

For more information about pacman, you can find the man page here: https://www.archlinux.org/pacman/pacman.8.html