DEADLY HOUSE FLY.

Lyttelton Times, Volume CXVII, Issue 17907, 28 September 1918, Page 7

DEADLY HOUSE FLY.

(By F. W. HILGENDORF, D.So.) 111. EARLY PREVENTIVE MEASURES. Last autumn I wrote for this journal two articles describing the dirt carried by house flies, the dangers of allowing them to become numerous in our homes, and the simplest means of suppressing them at that season of tho year. Tho articles wero written at that time, not because autumn is the season in which fly control can best be carried out, hut because the pest was then still witli us, and it was Hoped that the flies themselves would emphasise the argument of the articles. It is unfortunate, however, that by the time spring comes wo have largely forgotten the annoyance that the flies caused us in the preceding summer and autumn, and so. at the very time of year that preventive measures are most effeotive we are not sufficiently interested to take even the simplest steps to avoid the trouble that always recurs in the later parts of the season. It is in the hope of stirring our latent interest that this article is written at a time of year whea almost no flies are to be seen. The house-fly spends the winter in its adult stage, hiding in a dormant state in any crack or crevice until the return of warmer weather. Just about this season theeo winter flies emerge and creep sleepily about during the warmer days. It- is these flies, and these alone, that are responsible for tho swarms that will afflict us later on.

A single female fly will lay from 100 to 150 eggs in a batch, and these- under favourable circumstances will pass through their larval and pupal stages and emerge as adult flies in eleven days. Suppose we say 100 eggs, and calculate on double time for development, so as to allow for unfavourable conditions. Suppose, further, that the fly dies immediately after she has laid her ■ first batch of eggs, and that half of. her offspring are females. Then a pieco of simple arithmetic will show that if none of the eggs or young perishes, each female fly alive on the first of October will be tho progenitor of 31,250,000,000 flies by the first of February. Can anyone refuse to kill that number of flies when it may bo done at a single stroke? The stroke may be made by a duster or preferably by a fly whisk or " fly swat," which kills without crushing. These whisks may be bought at mos! ironmongers for a shilling, or may be made at home by tacking a piece of pliable wire gauze four inches square on to a nine-inch ];iece of wood to serve as a handle.