How do bedbugs overwinter? - briefly
During cold months, bed bugs enter «diapause», clustering in protected crevices and reducing metabolic activity to survive low temperatures. They remain inactive until ambient conditions become favorable, then resume feeding.
How do bedbugs overwinter? - in detail
Bedbugs survive the cold season by entering a state of dormancy that dramatically lowers metabolic activity. This physiological pause, often termed diapause, allows individuals to persist for several months without feeding. Temperatures below 5 °C halt development, while exposure to sub‑zero conditions results in mortality; thus, insects remain in locations where ambient temperature stays above this threshold.
Key physiological traits include:
- Reduced respiration rates, decreasing water loss and energy requirements.
- Accumulation of cryoprotectant compounds such as glycerol, which depresses the freezing point of body fluids.
- Maintenance of a stable internal water balance through cuticular lipids that limit desiccation.
Behaviorally, bedbugs select shelters that provide thermal insulation and stable humidity. Common overwintering sites are:
- Cracks and crevices in walls, especially near heating ducts or radiators where residual warmth persists.
- Furniture joints, mattress seams, and box‑spring cavities that retain heat generated by occupants during winter.
- Aggregation in large groups, which creates a microenvironment with higher temperature and humidity than surrounding air.
Environmental factors influencing survival:
- Relative humidity between 70 % and 90 % mitigates dehydration, a primary cause of winter mortality.
- Nighttime temperature fluctuations are buffered by the mass of building materials, preventing rapid cooling.
- Presence of a host, even intermittently, can extend survival by providing occasional blood meals that replenish energy stores.
Control implications focus on disrupting these protective conditions. Removing clutter, sealing cracks, and reducing indoor humidity lower the suitability of hiding places. Thermal treatments that raise temperatures above 45 °C for several hours can eradicate dormant populations, while cold‑exposure methods must sustain temperatures below −10 °C for a minimum of 72 hours to ensure complete lethality.