Cold tolerance in insects

Definition

The capacity of insects to survive exposure to suboptimal or subzero temperatures through mechanisms that either prevent freezing (freeze avoidance) or endure ice formation in extracellular spaces (freeze tolerance). These strategies involve cryoprotectant synthesis (glycerol, sorbitol, trehalose), ice-nucleating proteins, membrane restructuring, and metabolic suppression. Cold tolerance varies seasonally (cold hardening), among developmental stages, and across latitudes, directly shaping species distributions, overwintering success, and responses to climate change.

Etymology

Example

The goldenrod gall fly Eurosta solidaginis is freeze-tolerant: larvae accumulate glycerol and sorbitol in autumn, allowing them to survive internal ice formation at −30°C or lower, whereas the Antarctic midge Belgica antarctica relies on extreme freeze avoidance and rapid cold hardening to prevent ice nucleation in its habitat.

Synonyms

• cold hardiness
• chill tolerance
• low-temperature tolerance

Related Terms

• freeze avoidance
• freeze tolerance
• cryoprotectant
• cold hardening
• supercooling point
• thermal tolerance
• Diapause
• overwintering biology
• rapid cold hardening
• ice-nucleating protein

Usage Notes

Distinguish from chill tolerance (survival of cold above freezing without freezing) and cold shock (acute injury from rapid chilling). 'Cold hardiness' is often used interchangeably but sometimes reserved for seasonal preparation. Freeze tolerance and freeze avoidance are mutually exclusive strategies at the individual level; most temperate insects use one or the other, though some species switch strategies by life stage.