[2] It is an important vector of Trypanosoma cruzi (the causative agent of Chagas disease),[3] found particularly in Brazil.

[1] Besides humans, P. megistus is known to feed on birds, rodents, horses, dogs, opossums and bats.

[2] P. megistus is frequently found in domestic dwellings in Brazil, while in other countries it is largely a wild species.

[2] Within Brazil, the P. megistus's range stretches from the northeast to the south of the country,[4] corresponding roughly with the Atlantic Forest region, though the species also occupies parts of the caatinga and cerrado ecoregions.

[2] The states of Bahia and Minas Gerais have the highest populations of P. megistus in Brazil.