Genome-scale data have expanded the resolution of insect systematics, yet greater resolution does not guarantee that categorical species boundaries become biologically clearer. Population structure, introgression, geographic clines, recombination landscapes and marker-specific histories can generate discontinuities that are real in the data while remaining ambiguous in taxonomic meaning. This article develops a proposed threshold-sensitivity framework for deciding when genomic partitions are sufficiently stable and biologically corroborated to inform species hypotheses without treating analytical cut-offs as species criteria. The framework separates continuous population structure from biological discontinuity, represents gene flow as graded and potentially asymmetric, interprets geographic clines as spatial evidence rather than categorical boundaries, and distinguishes barrier-consistent genomic islands from differentiation amplified by genomic architecture. Taxonomic conclusions are then evaluated across a reasonable analytical neighborhood comprising defensible changes in marker set, data quantity, method, parameterization and reference geography. Stability across that neighborhood increases confidence only when supported by evidence with partly independent error processes; instability instead identifies where taxonomic rank remains contingent on analytical choice. The framework is qualitative and requires prospective evaluation across insect radiations, hybrid zones and cryptic species complexes. Its purpose is not to eliminate thresholds from analysis, but to prevent operational thresholds from being mistaken for biological discontinuities.
