How do fleas withstand frost? - briefly
Fleas survive freezing temperatures by entering diapause, a dormant stage that reduces metabolism and triggers production of antifreeze proteins that inhibit ice crystal formation. These adaptations keep both adult insects and their eggs viable until warmer conditions return.
How do fleas withstand frost? - in detail
Fleas survive sub‑zero conditions by entering a dormant stage known as the adult winter quiescent phase. In this state metabolic activity drops dramatically, reducing the need for energy and limiting ice formation inside tissues.
Key physiological adaptations include:
- Production of antifreeze proteins (AFPs) that bind to nascent ice crystals, preventing their growth and protecting cellular membranes.
- Accumulation of cryoprotective polyols such as glycerol and sorbitol, which lower the freezing point of body fluids and stabilize proteins.
- Regulation of membrane lipid composition, increasing unsaturated fatty acids to maintain fluidity at low temperatures.
- Dehydration of the exoskeleton, which reduces the amount of free water available for freezing.
Behavioral strategies complement these mechanisms:
- Seeking insulated microhabitats, such as the fur of host animals, nests, or leaf litter, where temperatures fluctuate less severely.
- Aggregating in clusters, which creates a microenvironment with higher humidity and slightly elevated temperature due to collective metabolic heat.
When temperatures rise above the lethal threshold, fleas resume normal activity, feeding on blood and reproducing. The combination of biochemical, structural, and behavioral tactics enables the insect to persist through winter without significant mortality.