DG-48.1 Hypothesis on the Chemical Detection Threshold of Varroa: Signal-to-Noise Ratio, Sensory Resolution, and Colony Regulatory Coherence

This conceptual research draft proposes that the persistence of Varroa destructor in honey bee colonies can be explained by a threshold-based limitation in chemical detection rather than a simple failure of colony defense. Honey bee colonies show highly coordinated collective responses to chemical disturbances (e.g., propolization, hygienic removal). However, Varroa destructor may evade detection by producing sub-threshold deviations within brood-cell microenvironments and by aligning with host chemical cues. The hypothesis argues that detection efficiency depends on the signal-to-noise ratio within the nest’s chemical landscape. When microbiome integrity, pheromonal coherence, and metabolic stability are high, background chemical “noise” is low and subtle parasitic signals become detectable, enabling timely hygienic responses (including VSH-related behaviors). When systemic stress elevates baseline variability, sensory resolution decreases, detection thresholds rise, and parasitic masking becomes effective. The framework integrates chemical ecology, microbiome dynamics, and colony-level regulatory architecture into a unified interpretation of Varroa resistance as a function of systemic coherence and buffering capacity. The document is intended as an open hypothesis for critique and empirical testing.