Insects face challenges during winter, including freezing temperatures and limited resources. They use various strategies to survive, from entering dormancy to producing antifreeze compounds. The list below outlines these survival tactics and how different species adapt to winter conditions.
Diapause
Many insects enter a state of suspended development and metabolic activity to survive unfavorable conditions. This can occur in various life stages, such as eggs, larvae, pupae, or adults.
Examples: Gypsy moth (Lymantria dispar), Colorado potato beetle (Leptinotarsa decemlineata)
Migration
Some insects migrate to warmer climates to avoid the harsh winter. Moving to regions with abundant resources and favorable conditions helps ensure survival.
Examples: Monarch butterfly (Danaus plexippus), dragonflies like the green darner (Anax junius)
Freeze Tolerance
Freeze-tolerant insects survive subzero conditions by allowing ice to form in extracellular spaces while protecting cells with antifreeze proteins and cryoprotectants (like glycerol). These adaptations prevent ice-crystal damage and stabilize supercooled body fluids.
Examples: Woolly bear caterpillar (Gynaephora groenlandica), Antarctic midge (Belgica antarctica), mealworm beetle (Tenebrio molitor)
Clustering
Social insects like bees and ladybugs cluster together to retain heat and conserve energy. The combined metabolic heat of the group helps ensure survival in freezing temperatures.
Examples: Honey bee (Apis mellifera), seven-spotted ladybird (Coccinella septempunctata)
Egg Overwintering
Some species lay cold-hardy eggs that can survive freezing and hatch in spring when conditions improve. The eggs often have protective coverings or chemicals to prevent freezing.
Examples: Aphid (Myzus persicae), stick insect (Phasmatodea)
Burrowing
Many insects burrow into soil, leaf litter, or tree bark to escape freezing temperatures above ground. These habitats offer thermal insulation and protection from predators.
Examples: June beetle (Phyllophaga), tiger beetle (Cicindela)
Shivering Thermogenesis
Certain insects generate heat by contracting their flight muscles without flying. This strategy helps them maintain activity or protect their brood in cold conditions.
Examples: Bumblebee queens (Bombus), some moths (Eupsilia)
Nesting
Insects construct insulated nests or shelters to provide a stable microenvironment during the winter. These structures often shield eggs, larvae, or the entire colony.
Examples: Paper wasp (Polistes), carpenter ant (Camponotus)
