The purpose of this application, under Articles 23.9.3 and 81.2.3 of the Code, is to conserve the species-group names Heliconius tristero Brower, 1996 and Heliconius melpomene mocoa Brower, 1996 (Lepidoptera: Nymphalidae) for mimetic butterflies from the Putumayo region of southeastern Colombia by suppressing the senior name Heliconius melpomene bellula Brown, 1979. The authorship of this name is convoluted, bellula having been originally proposed as an unavailable quadrinomen and made available by Brown (1979). More significantly, because the implied holotype of Heliconius melpomene bellula Brown, 1979 does not belong taxonomically to the species whose oldest available name is Heliconius melpomene (Linnaeus, 1764), H. melpomene bellula Brown, 1979 is not a subjective synonym of H. melpomene (Linnaeus, 1764). Strict application of the Code would synonymise H. tristero Brower, 1996 with H. bellula Brown, 1979 and retain H. melpomene mocoa Brower, 1996 as a valid name. That action would reverse the current application of nomenclature for these taxa as published in numerous recent papers and result in significant confusion. Furthermore, given current disagreement among authors as to the taxonomic status of the specimen associated with the description of the name bellula, future nomenclatural instability is likely if the name is maintained. It is therefore proposed that the name Heliconius tristero be conserved and the name Heliconius bellula be suppressed.