Nancy Garcif, age 12, of Elmhurst, New York, for her question:
Where do mosquitos spend the winter?
Sometimes it seems as though nature does not care a hoot about our convenience. Summer is the season for picnics and fun outdoors. It is also the season of pesky mosquitos. When winter is too cold to enjoy picnics, the mosquitos have departed from our favorite outdoor places.
It is some consolation to know that most of the mosquitos that haunted your summer picnics will have perished by Christmas. Of course, in most places, the Christmas aeason.is no time for picnics but it is still a bit cheering to know that the wintery weather is fatal to those squadrons of enemy insects. To a young naturalist, this, of course, poses a problem. If all or almost all the flying mosquitos perish in the late fall, how in the world can nature produce a new crop to pester us next season?
The truth is that the wretched creatures are in hiding through the winter. Insects do not grow up bit by bit from babyhood as cats and dogs do. Instead, their life cycle i& a series of different stages. The mosquito goes through a process called metamorphosis. This dramatic process transforms it into an entirely different creature. In winter, next summer's mosquito is in an unrecognizable dormant stage in a very unexpected hiding place.
The mosquito is an amphibious insect, spending three quarters of its life in the water and the rest as a winged flier in the air. Mrs. Mosquito lays a raft of eggs on some lake or lazy stream. The floating raft is made from 50 to 200 small, white, cone shaped eggs,. standing. on end and packed together side .by side. The eggs may spent the winter to this ' dormant stage. After a few warm days, they hatch and become small water bugs. With hammer shaped heads.
The mosquito larva is a fierce little tiger greedy fox bits of plant and :animal debris,. It is a, good swimmer always eager.to attack its neighbors., But unlike other water dwellers, the mosquito grub is an air breather. It.must come to the surface to get. oxygen. In a week or so, the grub is ready to advance to the pupa stage. It rises to the. surface once more, and seals itself inside a leathery chrysalis. There it rests hanging with its ;tail end down. After a few sunny days, a transformation takes place inside the chrysalis. It cracks open and out struggles a winged adult mosquito.
Our worst enemy is Mrs. Mosquito, for the male insect cannot sting us. What's more, it is the female who lays the eggs for more of her kind. During the summer, she produces brood after brood. The last batch of eggs stays dormant until spring, floating innocently on some watery surface. In Alaska, hordes of dormant mosquito eggs hide under winter snow.
The squadrons of flying mosquitos that annoy us in summer also are unpopular with the Board of Health. We can down them with sprays of insecticides. But experts say there is an even better way to eliminate them. In spring, they spray oily films on water surfaces which may be harboring the young mosquito larvae. The oily film suffocates the air breathing larvae, and the pesky dive bombers are destroyed before they change into airborne adults.