Everyman's enemy: the housefly (1955) Pt. 2 of 2

Bulk refuge containers are an improvement on individual dust bins for the disposal of waste material from blocks of flats and shops. They minimize the opportunities for flies to reach the refues and also make the task of collection much easier. When flies cannot enter a bin to lay their eggs in it, the problem of controlling flies at the tip is made easier as the incoming refuge does not contain large numbers of lavi. But inevitably adult flies congregate at refu tips and some breeding is bound to take place. The fresh refuse which is brought to the tip on the collection vehicle and deposited near the tip face requires prompt attention. First, it is pushed into place and is then ready for treatment with insecticide. Spraying should be carried out as soon as possible, otherwise the flies quickly make use of their opportunity to lay eggs. When refuse is seething with larae of various stages, fly control becomes more difficult as whatever insecticide is applied to the surface, adult flies will later emerge. Regular spraying of all fresh refu is essential. Power-driven sprayers are an advantage on tips with a large area to be covered and they reduce the manual effort involved. DDT in imulsion form is widely used for controlling flies on tips and it is a good insecticide against flies which are not resistant. The extent of DDT resistance is sometimes exaggerated. But where there is genuine resistance, an insecticide with a different mode of action such as malathione is required. Bucket pump and napsac sprayers are convenient for applying liquid insecticides both as emulsions and wetable powders. Napsac sprayers with polyine containers are light and have the added advantage that the amount of insecticide raining can be seen at any time. Where water is not readily available at the tip and where it cannot be brought there in a drum, insecticidal dusts may be used, although liquid sprays are generally preferable. For successful fly control, regular treatments at the recommended rates of dilution and application are vital and fresh services should not be left untreated. When the refuge has been crushed beneath the wheels of the collection vehicles and tractor, it should be covered with a layer of fine covering material, preferably soil, at least 6 in thick when packed tight. Flies are unable to emerge through an adequate layer of covering material. A loose thin covering is actually worse than none at all as it keeps the surface refues warm and provides the l with ideal conditions for pupation. A well- covered and consolidated area presents the flies with no opportunity to reach the refu. A well-managed tip where spraying is carried out regularly never gives serious trouble and has only a small fly population. Under the slaughterhouse hygiene regulations 1958, the occupier of every slaughterhouse is required to take steps to prevent the presence of flies. For daily application to manure heaps, gamma BHC dust is a suitable contact insecticide. Malathione wetable powder is a good insecticide for applying as a spray to wall surfaces when a product with residual properties is required. During the summer, a constant war has to be waged in food factories against flies and in many cases wasps. Also, the insects which succeed in entering a food factory in spite of screening are best dealt with by regular mist spraying using pythine insecticides which are safe in the presence of food stubs. Before spraying, any exposed food and vessels should be covered to prevent insects affected by the insecticide from falling into them. The Microsol mist generator number 202 is capable of putting up a mist of oilbased pyuine insecticide into a space of about 50,000 cubic feet from one position. It can however be carried about by the operator or alternatively two machines may be used in widely separated positions for large factories. The Microsol number 303T is required. It is very easy to maneuver. has a tank with a capacity of 4 and a half gallons and an output rate of about six to 10 times greater than that of the Microsol number 202. When this machine is adjusted to give a fine mist which will remain in the air for some time, it can be used to treat a space of half a million cubic feet in about a quarter of an hour. Both the Microsol 303T and the 202 are useful for localized treatments against fruit flies which gather in areas where syrup or fruit juices are handled. In hospitals, aerosol fly sprays are the principal weapons for fly control. They are clean, save valuable time, and when based solely on pyuine can be used with perfect safety. They are often used in the operating theater even while an operation is in progress. Also in shops and catering establishments, aerosols give quick and easy fly control. Carefully conducted scientific experiments are constantly in progress to ensure that safe and effective insecticides are produced for all aspects of fly control work. Air sprays can be conveniently tested in a small experimental chamber. A known quantity of the insecticide under test is released into the ch and the number of flies which are knocked down are counted at definite intervals. After 10 minutes exposure, the flies are collected and retained in a jar for 24 hours before the number killed is determined. A special room technique is employed for assessing the efficiency of aerosol fly sprays. First, the aerosol mist is put up at the rate of about 3 g to 1,000 cubic feet. Then the flies which have been carefully reared and prepared for experimental purposes are released from bags. As with conventional space spray tests, counts of flies knocked down are taken at definite interval. All the flies are collected at the end of the exposure period and kept for 24 hours before a determination of kill is made. Tests such as these make sure that insecticides are produced which when used correctly will do what is required of them. There is no single way of solving the problem of fly control and many lines of attack are needed. We must ensure that all fly control measures are carried out properly and with the most efficient insecticides so that the best possible results are achieved. The housefly is every man's enemy. Kill it. [Music]