INSECT SURVIVAL STRATEGIES IN NATURE DURING WINTER(RAHIMA)

Insects have a variety of methods for surviving the freezing winter temperatures. Migration is an example of a strategy used for escaping the freezing temperatures. The Monarch Butterfly is well known for this strategy; crop pests also utilize this strategy. Overwintering as larvae is another common strategy where insects successfully pass the winter as immature larvae. The protection of heavy covers of leaf litter or similar shelters protect the woolly bear caterpillar, while other insects replace the water in their bodies with glycerol which acts as an antifreeze. Other larvae usually burrow deeper into the soil to escape the cold. The nymph stage is also known to have overwintering behaviour. Not many insects are active in the winter, but the nymphs of dragonflies, mayflies and stoneflies live in waters of ponds and streams, often beneath ice. They feed actively and grow all winter to emerge as adults in early spring.

Overwintering as Eggs. Lesser numbers of insects lay eggs which survive the winter. The most prominent insects in this category are Praying Mantids. Overwintering as Pupae. Some insects overwinter in the pupal stage, then emerge as adults in the spring. Moths in the Silkworm Family, Saturniidae, may be found attached to food plant branches as pupae in the winter. Finally, the last strategy is hibernation as adults. Lady bird beetles are a well-known example, and are sometimes seen in great numbers in the fall as they congregate at high elevations. Many large wasps seek shelter in attics of houses or barns. Tree holes, leaf litter, and under logs and rocks are common shelters for overwintering adult insects. Just like in some insect larvae, it reduces the body water content and builds up glycerol which acts as an antifreeze. Honey bees stay in hives during the winter, and form clusters when temperatures fall. They also are able to raise the temperature by vibrating wing muscles.