MOSQUITOES

Hokitika Guardian, 7 November 1932, Page 7

MOSQUITOES

METHOD OF CONTROL.

For centuries it has been, realised that the most serious difficulties in the development of the tropics are diseases peculiar thereto. Not till early in the present century wag it shown that mosquitoes cause certain of these diseases such as yellow fever and malaria, for instance. When a mosquito bites she injects into the victim a fluid from her salivary glands through a tube-like arrangement. In This fluid are-sometimes the organisms i.which produce malaria. To quote Dr. Shipley “Down this minute microscopic groove has flowed the fluid which has closed the continent of Africa for countless centuries to civilisation and which has .played a dominating part in destroying civilisation of ancient Greece and Rome.” New Zealand is indeed fortunate' that such diseases as mentioned are not prevalent here. The particular types of mosquitoes which convey these troubles have not so far been proved to exist in the Dominion. However the reduction of mosquitoes in badly intested areas will reduce the likelihood of the disease carrying forms becoming established. Mosquitoes are always a nuisance and the annoyance they cause is in itself sufficient reason for measures towards their suppression. They are also liable to contaminate water for the pressure of mosquito larvae has been shown to increase the bacteria contents of water in which they breed,

control METHODS

The control of the mosquito is largely the control of breeding places. That man can be successful in his campaign even against an elusive enemy like the mosquito is proved by . the results which have attended the American campaign in the Isthmus of Panama and Havana. The best results are obtained l by communal efforts directed by persons who have some real knowledge of mosquitoes and .their habits but. individual efforts are of great importance. The presence of mosquitoes in the home is good evidence that they are breeding in some' place near the house. Certain natural enemies are of service, fish are very effective. The margins of pools, streams, and so forth, should he kept free of vegetation to allow the fish access! ornamental ponds may be stocked with goldfish or minnow. Anything which collects water should be deal with. Stagnant. brackish water amid the rocks of the foreshore is a happy breeding ground. Old tins, bottles and the like should be removed and buried; spouting must he cleared and if possible receptacles emptied at least once a week and , allowed, to become quite., dry before, refilling. Much may he done by the draining and abolition of, swamps, filling in of ponds and depressions,, and the straightening and ole’anlng of streams and ditches or by the use of drain pipes. Unnecessary scrub may be cleared; but it is useless if water remains. Where water cannot be removed such should he sprayed weekly with kerosene. The water must he covered with a complete layer of oil. two tablesponfulls should cover 15 sq. ft. of surface. A good spray mixture is kerosene 60 parts, fuel oil 40 parts. These oil films kill the larva© by preventing breathing. The addition of a little castor oil to the kerosene gives a. better film. The following larvicides are ’’effective: (1) Commercial cyllin, 1 teaispoonful to a gallon of water, or enough to make the water milky when stirred; (2) Coal tar 1 pint, turpentine 1 pint, soft soap 1 oz., water to make up two gallons; this will treat three hundred gallons of water; () Receptacles containing, drinking water which cannot be oiled should be screened or treated with 1 part of copper sulphate to every 500 parts of water,.

Friars Kalsam allays l)ites. Citronella oil will protect the face and ha mb; to some extent. If this stains the clothes the stain can be removed hv oil of turpentine. Any village or city that can claim it is free from mosquitoes soon becomes an ideal place for tourists and those seeking summer homes or permanent places of abode. (Contributed by the Department of Health.)