Table 1 Species concepts and their implementation

Strict biological

Species are characterised by near complete reproductive isolation.

Semi-species which hybridise freely are lumped.

[41]

Relaxed biological

Species are characterised by substantial but not necessarily complete reproductive isolation.

Semi-species given full species status, c.f. current heliconiine taxonomy.

[42]

Genotypic cluster

Species are delimited by the presence of gaps between clusters of multilocus genotypes within a local area.

Semi-species given full species status.

[44]

Diagnostic phylogenetic

Taxa differing at fixed, diagnostic traits are given species status.

Current heliconiine subspecies raised to species status.

[56]