Papilio prexaspes once treated as a ssp. of P. fuscus was elevated to a full species because its genitalia differs from that of P. fuscus.
Papilio prexaspes : range Andamans to Neomalaya (Sumatra, Malaya & Borneo )
Papilio fuscus : range Sulawesi to PNG/Australia.
ie. P. fuscus no longer exist in Borneo.
See C&P4 page 69.

The Borrnean taxon dayacus becomes a ssp of P. prexaspes.
This Sarawak form may qualifies as another ssp.

TL Seow: Cheers.