P. comastis is endemic to New Zealand. It can be found in the South Island. Meyrick stated that the species could be found at Castle Hill and Christchurch. Hudson added to the locality list and included Lake Rotoiti, Wedderburn and New River, near Invercargill. Philpott collected the species at Red Lake in the Mount Cook district. It has also been collected in the Dansey ecological district in Otago. It is present at higher elevations.