Pretty self explanatory. As I understand, the broodlings from a broodlord have two different attacks: the first attack is an air attack (using air upgrades), and subsequent attacks are melee ground attacks.
I guess guardian shield has no effect for those subsequent attacks, but what about the first attack?
Best Answer
According to Team Liquid the Brood Lord does count as a ranged unit, but is not affected by guardian shield.
Secondly, like you mentioned, all subsequent attacks by the broodlings are melee and are also not effected.