The Gisborne Times. PUBLISHED EVERY MORNING. TUESDAY, SEPTEMBER 7,1909. CONQUERING THE MOSQUITO.

Gisborne Times, Volume XXVII, Issue 2600, 7 September 1909, Page 4

The Gisborne Times. PUBLISHED EVERY MORNING. TUESDAY, SEPTEMBER 7,1909. CONQUERING THE MOSQUITO.

Modern science has performed no greater service than in telling us how great a part is played in the health of a community • by common and comparatively insignificant insects. It is now recognised even by the layman that typhoid is largely the work of the übiquitous and filthy household fly, and the American experts who took up the work of constructing the Panama Canal commenced by a war of extermination on the fever breeding mosquitoes. On these same lilies a notable work has been in progress at Staten Island 1 — which is virtually one and the same as the Borough of Richmond, just outside New York City. Until a few years ago this place, which accommodates a population of 50.000 people, had a most unenviable reputation by reason of an annual plague of mosquitoes, which made life a burden to the inhabitants during the summer months. Apart from the real inconvenience to local residents the pest was a menace to business, for -the wealthy New Yorkers who, in the ordinary way would rent villas or patronise hotels and restaurants along the beach, declined to share the salubrious? atmosphere of this desirable locality with such aggressive insects. Then it was that science came to. the rescue in the person of Dr. A. H. Doty, a member of the Board of Health of New York City. His methods are indicated in the following extract taken from “Harpers’ Weekly”:— When men in the uniform of the Health Department were found prowling about back doors, looking into rainwater barrels and cisterns, and searching for stray receptacles that might contain stagnant water, they referred all questions as to their right of invasion of private property to Dr Doty. If the invaders gave orders that all unused and exposed articles that might contain water, such as tin cans, pails, pans, and glassware, be removed; that cisterns and rain-water barrels be provided with tight-fitting covers of, wire netting, and indignant property-ow-ners desired to know who it was that dared to dictate to them about their domestic arrangements, they;-were informed that Dr Doty was the responsible person. When the Health Department men came around with a big oil-tank wagon and sprayed any little pools of water in the vicinity of the houses with ill-smelling petroleum Dr. Doty was mentioned as answerable for the outrage; and when these men began to teach tho children that the “wigglers” in stagnant water were mosquito larvae distributed glass tubes, promising payment for imprisoned mosquitoes to be brought to the Quarantine Station, it was ascertained that Dr Doty was accountable for the transaction. When men were found digging ditches across the salt marshes of the island and the natives were told that this move was also a part of the project for the annihilation of the mosquito'they felt convinced that the instigator was of unsound mind. Dr Doty was dubbed as a, meddler and a busybody, but to-day the people of Staten Island are talking of erecting a monument to “the mosquito man” as he was called. He has rid them entirely of the striped-legged mosquito, the savage Culex sollicitans, that, besides driving away no one can compute how many potential residents, has hitherto made life a burden during the summer months; arid he has all but annihilated the anopheles, its malaria-car-rying relative.; The conquest of the mosquito has increased the value of real estate on the island by hundreds of thousands of dollars; new houses are going up throughout its length arid breadth, and residences that have long been inhabited only by caretakers are being rented. As can be imagined from this achievement Dr Doty has made a special study of the mosquito and its habits.

He tells us that there were two varieties of the insect at Staten Island; one the anopheles, to which was due the malaria that, prevailed in the interior, and the other a striped-leggod fiend called Culex sollicitans which, while not known to convey disease, outnumbered the other, by three to one, and was a most vindictive and torturing pest. Neither can breed except in water, the anopheles in fresh water, and the Culex sollicitans in salt water.

Dr Doty’s researches show that the water in which mosquitoes breed must be continually present for about two weeks in order to allow of the full propagation of the insect, and that they are not produced in water that may accumulate for two or three days or a week. They will breed, however, wherever there is standing water. The anopheles larvae are frequently found in the most unexpected places, such as old glass and tinware, wooden receptacles, defective roof-leaders, and the crotches of trees. As, with the exception of the sollicitans variety, mosquitoes do not go far from their breedingplaces, if any others are found about the house it is almost certain that a breeding-place exists in the immediate vicinity. Filthy water or that which contains an excess of organic matter is generally preferred by the anopheles mosquito for this purpose, so that obstructed cesspools, street gutters, and similar places are found to be favorite breeding-spots. The mosquito deposits its eggs on the surface of the water, usually at night, and from fifteen to twenty hours afterward the larvae are released., Although the larvae can live only in water, they are dependent entirely on air for existence, and must rise every minute or so to the surface and project above it their respiratory apparatus. Petroleum does not poison tho larvae, but kills them by suffocation, as the oil on the surface of the water plugs up the respiratory apparatus and prevents the intake of air. As the sollicitans variety can only breed in salt water swamp land it can be destroyed by drying up these swamps. The manner in which this New York scientist has successfully combated the mosquito scourge might easily provide ah inspiration for the Gisborne health officers during the summer that will shortly be with us.