How do insects adapt to survive winter?
Insects are cold-blooded creatures, which means they are especially susceptible to low temperatures. So, in order to survive this time of year, the animals developed a series of adaptation strategies that ensure the continuity of the species. Check out some of these alternatives according to the Today I Found Out website:
Insects that have migration as a characteristic of the species do not waste time when temperatures drop. The monarch butterfly is an example of insects that choose warmer places to spend the winter. In this way, the insects travel in search of a milder climate and return in the spring, when the sun warms up again.
Many insects are known to seek shelter so they can take a break. This means that they enter an inactive state of development that is similar to the mammalian hibernation process. For this, insects accumulate extra layers of fat and reduce the amount of water they have inside the body.
Eliminating water - which freezes at relatively higher temperatures compared to other liquids - is critical to creating an environment that makes ice formation impossible. They also get rid of which traces of food, dust or bacteria, since a single speck of dust is sufficient for water to crystallize. Otherwise, the liquid may cool to -42 ° C without freezing.
The different species strategies
Larvae, eggs (which are stages of development where the insect does not need to feed) and pupae (where non-actively feeding species can be found) can survive very low temperatures. Therefore we can find the cocoon of some species, such as the silkworm, trapped in the branches of plants during the winter. In general, the leaves or other branches of the plants are sufficient to provide shelter from the cold.
Most adult insects, however, seek to hide in places where they can keep warm and not easily found by birds and squirrels. Among those sheltering in tree bark, it is common to find them in the lower part of the trunk, where there is a chance of contact with the heat of the sun. Other species, such as ladybugs, choose from buildings, attics, barns and other structures where they can stay away from the cold.
On the other hand, insects that have a collective behavior, such as ants and termites, stay in colonies built many feet deep from the frozen earth's crust, where they have huge amounts of food stored. Bees also think of the collective and group themselves into a compact ball-like shape. Inside this structure, bees generate heat by vibrating their wing muscles, while outside insects remain immobile to isolate the heat. They rotate positions, with the queen bee always kept warm in the center of the group.
Aquatic insects, such as dragonflies and ephemerals, spend the winter as nymphs (one of their developmental stages) and take the opportunity to feed a lot and reach adulthood in early spring. In addition, these insects seek warmer waters as needed and have undergone an adaptation process that lowers the temperature at which they begin to freeze.
Wasp nest covered by snow. Source: Shutterstock
Finally, some insects simply cannot escape the harsh winter and have to find a way to adapt to the ice-covered surface. Freeze tolerance is a more common phenomenon in the Southern Hemisphere, where climate varies more easily. Because of this, some types of caterpillars, cockroaches, and other insects have developed a mechanism that allows them to purposely freeze part of their bodies (specifically and at specific times) to prevent the harmful effects of ice. This is important to avoid thermal shocks or a total freeze, which can be fatal to insects.
* Posted on 26/04/2014