THE HOUSE FLY

[Music] the common house fly though always uninvited is one of the most frequent of guests at our dining table and in our kitchen if all of us realize the Flies filthy habits and how it endangers our health and our lives we would wage a constant war against it the common housefly is one of the most deadly spreaders of disease in order to control or destroy this dangerous pest we must know the story of its life and its habits the house fly usually lays its eggs in Animal refu here the heat given off by the decaying and rotting refu helps to incubate the eggs the motherfly Lays her eggs with this long tube the white masses below this fly are clusters of eggs here you see them highly magnified about 100 eggs are laid at one time but each motherfly may lay five batches during her life under favorable conditions these eggs will hatch within 24 hours into slimy larvey which we call maggots these maggots are wriggling creatures less than a qu of an inch long the head is at the pointed end there is a knob on the head which the maggot uses to pull itself along the maggots feed and grow in the filth they're soft juicy bodies are relished by Barnyard chickens who uncover them by scratching the chickens are unable to find and devour all of them the maggots dread sunlight so when they are uncovered they immediately begin to dig into new hiding places after about one week the maggots Dig Down Deeper here the last skin of the maggot shrivels up and becomes the dark brown protective coat of the pupa this third stage usually lasts about 5 days unless it is late in the fall then it may remain as a pupa through the winter near the top of this picture you see a fly breaking out of the pupic case aided by its expander this expander is located on the head of the fly when the body Juices Flow into the expander it swells and breaks open the pupic case as the fly pushes upward this expander swells and shrinks a number of times thus forcing the edges of the pup case aside with great effort the fly fights its way out from this magic chamber the Young Fly struggle to live has just begun at the bottom of this scene several flies have just emerged from their pupic cases at this time they are a few inches below the surface of the ground the Flies begin to crawl toward the surface the EXP Lander on the front part of the head continues to clear the way with the aid of its legs the fly crawls upward toward the open air and freedom this fly has been taken out of the ground to show you how its expander works it sometimes happens that the body Juices Flow into the wings and cause them to expand before the fly reaches the surface when this happens the expander ceases to work and the wings anchor the fly in an underground death chamber the wings of this fly have not expanded it crawls up and up and finally reaches the surface now after the fly has emerged the Juices Flow out of the expander and into the wings causing them to unfold the fly's Keen sense of smell guides it to food often in the kitchen or in the garbage can we have seen that the house fly has four stages in its life history it begins with the egg which is laid in Barnyard manure or refug then follows the maggot stage during which the creature feeds and grows when full grown the maggot passes into a resting stage the pupa this is followed by the for or adult stage of the fly the head of the house fly is almost covered by two large compound eyes each of these consists of hundreds of small eyes the mouth parts are located below at the end of the long trunk if the fly is feeding on solid food it first forces up a liquid from its stomach to dissolve the food here is a fly's foot seen through a microscope disease germs May collect on the many small hairs we will let a fly walk across this specially prepared gelatin plate this view taken a few days later shows that the Flies tracks have become threadlike lines which are colonies containing millions of germs here you see some of them under a microscope they are the germs of typhoid fever because of their filthy habits flies may carry such germs to our food typhoid and summer diarrhea are nearly always brought by flies not only do flies carry germs on their bodies but since they feed on filth they take the germs into their stomachs when a fly visits solid food such as sugar and brings up the liquid from its stomach to dissolve the sugar it leaves the familiar fly spots which may contain millions of germs here are The Offspring of a single mother fly and each one of these female flies in turn will have millions of Offspring by Autumn therefore it is wise to destroy the early spring flies flies may be controlled in homes by means of fly paper the fly swatter and screens on Windows and Doors but the best way to meet the fly Menace is to eliminate all possible places where the Flies May breed manure heaps unless sprayed with poisons should be removed every other day a huge garbage dump like this is a disgrace to a community it is not only unsightly but offers a breeding place for flies garbage should be placed in a can with a cover to keep out FES the garbage should be collected regularly and in a sanitary way the best modern way to dispose of garbage is to burn it in an incinerator thus if the entire Community cooperates the house fly carrier of Filth and disease menaced to the health of all mankind can be controlled