Grace Davies, age 12, of Wilkes Barre, PA., for her question:
HOW LONG DOES A FLY LIVE?
An adult housefly will live for about 30 days in summer. Some flies will live on into cool weather, but they are less active.
While most flies die when the weather gets cold, they leave larvae and pupae which stay alive and these develop into adults in the spring.
A female fly will lay from one to 250 eggs at a time, depending on the species. During her short lifetime, one female may produce as many as a thousand eggs. She will lay her eggs on water, on the ground or even on other animals.
An organ called the ovipositor is located at the tip of a female fly's abdomen. It is from the ovipositor that the eggs are laid.
A housefly's eggs will hatch in between eight and 30 hours, but the time depends on the species of fly. The common housefly is but one of about 100,000 different kinds of flies which can be found throughout the world.
From a fly's egg comes the larva, often called a maggot or a wriggler. The larva lives in food, garbage, sewage, soil, water or in living or dead animals and plants.
A fly larva spends all its time eating and growing. It sheds its shell and grows a new one several times as it grows. The larva stage lasts from a few days to two years, depending on the species.
The larva then turns into a pupa. Most pupa live on land and remain quiet in strong, oval shaped cases. Inside the case, the larva gradually loses his wormlike look and takes on the shape of the adult fly. The case is called a puparium.
After the change is complete, the adult fly bursts one end of the puparium or splits it down the back Ana owls out. The pupa stage of the housefly flasts from three to six days n hot weather and longer in cool.
When an adult fly leaves the puparium, its wings are still moist and soft. The air dries the wings quickly, and blood flows into the wing veins and stiffens them.
The thin wing tissue hardens in a few hours or a few days, depending on the species, and then the adult is ready immediately to fly away and find a mate.
A fly has reached full seize when it comes out of the puparium. A small fly grows no larger as it gets older, even though its abdomen may swell with food or eggs.
All flies have two wings. In addition to the common housefly, you'll also see blowflies, botflies, crane flies, deer flies, fruit flies, gnats, horseflies, leaf miners, mosquitoes, robber flies, sand flies, tsetse flies and warble flies.
A number of other insects are often called flies, but they have four wings and are not true flies.