Handbook of domestic science and household arts for use in elementary schools

Materials. — Insect powder, pennyroyal herb and oil, quassia chips, Chinese incense sticks, molasses, black pepper, egg, cooking soda, aqua ammonia, borax, salt, traps (homemade and patented), fly-drivers (home-made and patented), whisk broom, bits of meat " blown " by flies, liquids infested with fly " maggots " or pupse, atomizer, plates. Flies Diptera — Muscidae — Musca Domestica and Others Flies are a disagreeable, irritating pest to persons, and by their eggs they contaminate food supplies. Worst of all, their feet are admirably adapted for picking up disease germs, which may be carried, here as well as on the proboscis, from person to person, or from putrefying matter to person or food. This is true especially in cases of typhoid fever, where, as is often the case, the faeces, not disinfected, are thrown into the common privy, or allowed to stand uncovered. This last is the chief reason why flies should be kept out of the house. Especially is there great danger of such carriage of contagion, where there are babies, as they are unable to protect themselves, and their delicate membranes of eyes, nostrils, and lips are more sensitive than those of adults. Many cases are on record where the germs of consumption have been found in the bodies and in the droppings of flies, in rooms occupied by consumptive persons. It is true that flies are scavengers, and it is their work to aid in ridding the world of filth ; but we do not wish them to deposit the results of their scavenging upon ourselves or upon our food. There are a number of species which may be found in houses, but the most abundant is the true house fly, which cannot bite or pierce the flesh, its mouth parts being adapted simply for lapping liquids. Some of the stable flies, however, have mouth parts which can pierce the skin, and they often come into the house. It is not necessary to distinguish between the species, as all should be kept out, if comfort, economy, and health are to be maintained. The metamorphosis is indirect. The adults do not need description, although they well repay close observation and study, especially the head and feet. The favorite breeding place is horse manure, but the female will lay her eggs in all kinds of manure, as well as in any moist decaying matter — meat, fruit, garbage of all kinds. One dirty stable may furnish flies to a whole neighborhood. Dirty streets, neglected back yards, uncovered garbage barrels, invite the parent fly to deposit there her eggs. Each mother fly may lay over a hundred eggs at one time, and these pass through their four stages from egg to adult in from ten to fourteen days. The enormous numbers of flies are thus easily accounted for. The larva is a long, segmented form, larger at the anal end, but showing no head except the small antennae. Its mouth parts are hooks which aid in movement as well as in eating. The adults remain torpid during the cold weather, reappearing in May or June, but usually not laying their eggs until August. Thus the greatest danger to food supplies which invite egg-laying is in this month.