Bred in Back-Yards

Sun (Auckland), Volume III, Issue 780, 28 September 1929, Page 10

Bred in Back-Yards

Auckland Fights Mosquito Pest IF no further grant is made for research ■work into the mosquito problem, valuable investigation in Auckland will be suspended indefinitely. Knowledge already gained by expert workers has given the Government an inkling of the extent of mosquito breeding, but the research has not nearly reached an advanced stage. An expert calculates that- 80 per cent of Auckland’s mosquitoes are bred in the City’s back-yards.

At the moment, there are indications of the early abandonment of the study of the problem. There is a proposal on foot to eliminate mosquito breeding areas in Newton Gully, but the suggestion merely touches the fringe of a task which can be faced by community cooperation alone. Before results of the early researches were announced, Aucklanders knew the mosquito only as an objectionable pest. No attention was given to the Idea of combining to strike home at the insects by destroying their breeding localities. And who would have thought, seriously, several years ago of the frequent appearances on vessels reaching Auckland from tropical countries of malaria-bearing mosquitoes? Time and again investigators have advanced specimens of the fever carriers to support the contention that there could be a Southward drift of the insects, so demanding keen surveillance. Responsible research workers have said that the malaria carriers, reaching New Zealand’s shores in warm weather, could survive. Besides this aspect of the position, countless numbers of other kinds of mosquitoes from overseas have been trapped and destroyed in the holds of visiting vessels. The most prominent figure in the consistent investigation has been Mr. David H. Graham, who has worked under the direction of that necessary organisation, the Auckland Mosquito Control Committee. Mr. Graham’s studies were carried out with the assistance of a. research grant made originally by the New Zealand Institute and the Department of Health. EXTENSIVE BREEDING It was not long before Mr. Graham became cognisant of the amazing extent of mosquito-breeding in and near Auckland. In addresses and in comment on his researches, he quickly proved that Auckland had a tremendous obstacle to face in the event of efforts to eliminate the pest. Public opinion undoubtedly has been in favour of the operations of the research workers. Several considered statements by Mr. Graham soon aroused public attention in the question. For instance, in one address, he said: “Mosquitoes are breeding in eight out of ten backyards.” Again, he said that 6,000 adult mosquitoes could be bred in three weeks in a gallon of water. It is still Mr. Graham’s contention that, with combined efforts by the local bodies and the residents of Auckland, SO per cent, of the insects would disappear. Minor areas have

been cleared of breeding places, but a general movement to diminish the numbers of the pests has been lacking. Such a movement is regarded as an urgent requirement, and systematic inspections on visiting vessels are also advocated as a sensible precaution. Mr. Graham’s efforts in detecting mosquitoes in their cubby-holes have been remarkably extensive. He has found mosquito eggs in firebuckets on the Papakura railway station and in water retained in holes in tree trunks in the Waitakere Ranges. Mosquitoes are nothing if not catholic in taste in selecting breeding places. Rock hollows, axils of palm leaves, tyres and tins are equally desirable in the eyes of the pests. Stagnant, sheltered water is the ordinary preference. RESULTS PUBLISHED One result of Mr. Graham’s work has been the publishing recently in “Transactions of the New Zealand Institute” of his observations on three varieties of New Zealand mosquitoes. The habits of the varieties from breeding to maturity have been described comprehensively, and Mr. Graham has also prepared a series of sketches to explain his work. At the present time he is engaged in preparing a similar contribution to the knowledge of the pest, but whether or not his investigations are to be continued is indefinite. Inspection on the waterfront has been especially thorough, and swarms of insects from overseas have been caught by the small number of research workers engaged. Apart from the destruction of pests, valuable information has been gained for official records. But it has been in the backyards of Auckland and in unsuspected places that perhaps the most important public work has been carried out. A community campaign to destroy breeding grounds before summer brings the insects in their usual numbers would, if well organised and supervised, probably prove that the numbers of mosquitoes can be lessened noticeably by such an effort. Under expert guidance, the public could soon be tutored efficiently enough in the detection of likely breeding places. Mr. Graham has given it as his view that mosquitoes could possibly affect the milk yield in the Auckland Province. Other workers in the researches in Auckland have been Professor A. P. W. Thomas, chairman of the Mosquito Control Committee, Mr. F. L. Armitage, the secretary to the committee, and Mr. Gilbert Archey, curator at the War Memorial Museum.