Bonnette Wooten, age 12, of Charleston, W. Va., for her question:
WHY CAN'T INSECTS SURVIVE THE WINTER?
Obviously the insects do manage to survive the winter or they would have perished from the earth long ages ago. Actually, only the adults depart from the scene. Meantime, the next generation waits around to erupt in the spring. The main reasons for these stupendous turnovers in populations are temperature and sometimes food supplies.
The teeming insects are cold-blooded creatures, with no built in system to change food energy into body warmth. Their living cells, like all living cells, need a certain amount of heat to carry on their miraculous life processes. In other words, an insect needs to use warmth from surrounding objects in order to keep going.
As the fall weather sets in, most of our adult winged insects slow down and soon perish from the cold. Usually the final adult phase of life lasts only as long as the warm summer weather, though the cicadas, for example, may have lived 14 to 17 years in other life stages.
In most cases, insects in the adult stage seem to have but one purpose in life. Some species live only a few days and may not even pause long enough to eat. But every adult is determined to mate and produce offspring that can survive the winter and reappear as adults in the spring.
Every species has its own particular life story, and usually winter survival depends upon the structure of the early stages. For example, all insects lay durable, winter proof eggs. Some, such as the grasshopper eggs, hatch into a nymph stage, as miniature wingless copies of their parents. Naturally, these insects tend to spend the winter in the durable egg stage, waiting for spring before they hatch.
Butterflies and many others develop through four very different cycles. Some of these types may spend the winter as eggs. Others may live in the warmer ground as grubby larvae. Others spend the winter in the pupa stage, in cozy cocoons or weatherproof chrysalises.
In some species, adults feed on plant food or other insects. These supplies tend to dwindle and make life impossible during the winter. However, the main reason why most adult insects cannot survive the winter is cold weather.
As usual, there are exceptions to the general rule. Adult monarch butterflies migrate hundreds of miles to warmer winter climates. Honeybees lay in stores of nourishing honey and spend the winter huddled inside the warm, weatherproof hive.