Anti-Mosquito War

Need for Extensive Campaign

Brisbane Doctor’S Valu

Able Work

From Our Thursday Island Correspondent TO attempt to eradicate or even control that common pest of tropi cal countries, the mosquito, would seem to be a herculean task when countless thousands of them roam at large, in the course of an evening, through most people’s bungalows, in flicting torture on all and sundry.

And yet, thanks to the research of biologists and health workers, the problem does not appear to be so very difficult, when certain facts with re gard to the habits of these pests have been made clear.

Be that as it may, the attempt to make a city like Brisbane, which has many square miles of swampy land in its vicinity, mosquitoless is being tackled, and is even showing signs of eventual success. If this ideal is at tained, and the mosquitoes which carry the three principal mosquito-borne diseases —malaria, dengue and elephan tiasis —are completely driven out of the Queensland capital, its citizens will have to thank Dr. Hamlyn Har ris, D.Sc., of the Public Health Depart ment of Queensland, who has already accomplished much in this direction.

But Dr. Harris is not waging war against these enemies of man in Bris bane only, for, by means of a series of clear diagrams and instructions, he is now bringing the facts of mosquito control to the notice of all Queens landers.

“Species Control.”

Much benefit would result if these diagrams were distributed throughout the Pacific, for no one who takes the trouble to read them could fail to either grasp the principles or to real ise that mosquito control is a perfectly feasible suggestion which can be car ried out by any householder.

The solution of the problem, as Dr.

Harris remarks in one of his press articles on the subject, lies in what is

Called “Species Control.”

He states: Species control ignores mosquitoes taken as a whole, takes no cognisance of general pro miscuous control, but deals with each species of mosquito on its own merits, makes a study first of the habits and life history, and then determines the attack.

From an examination of the dia grams, we find that the mosquitoes of Australia are divided into three main classes, those that do not bite—appar ently they never visit Thursday Island —those whose bite is harmless from a disease-carrying point of view, and those who, when they bite, can, and often do, transmit the germs of dis ease.

The significant fact about this classi fication is that it is only the last named, the virulent carriers of malaria and dengue, that infest houses and breed domestically. The biting pest that hails from the swamps and is occasionally blown into settlements by the wind, is harmless, except in its power to torment and exasperate its victims and does not attempt to enter houses as a rule.

We are therefore only concerned with the purely domestic variety, and the swamp breeder may be left to his, or rather her, swamps, with the know ledge that if she is vicious on her occasional visits to town, she will not start up an epidemic of dengue or other tropical plague.

All tins, tanks or pools containing larval infested water should be emptied, or their surface covered with a thin film of kerosene or olive oil, and special attention paid to satur ated heaps of vegetable or animal re fuse.

It is by these methods that Dr. Har ris is urging Brisbanites to extermin ate mosquitoes, not by vigilance to-day or to-morrow but by everlastingly keep ing at it, and the same measures could be adopted throughout the Pacific by the expenditure of a little energy.

The Position On Thursday Is.

On Thursday Island the problem is no less important. The three disease bearing mosquitoes are all present there and are augmented from time to time by bush or swamp mosquitoes.

Every Anopheles is a potential mal aria-carrier, and our freedom from this disease up to the present is doubtless due to the fact that the mosquitoes themselves have hitherto escaped be coming infected. But how long can we expect to remain immune, when we have a host of Papuans from highly malarial districts living here, just at the time when the Anopheles is most active? Nor must we put the whole responsibility on the unfortunate New Guinea boys, when there are infected centres in our own islands, like Darn ley and Poid, from whence malaria could easily be carried to local mos quitoes by island visitors.

It has been prophesied that Thurs day Island’s immunity from malaria will end in a serious epidemic one day, such as occurred out in the is lands last year, but the danger of this might be averted by a little timely in vestigation and action bv the local council.