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either by catching or by hatching out larvae, but those of Aedes albopictus, (Stegomyia scutellaris) could be obtained without difficulty. In the Philippines, Aedes albopictus has been experimentally infected with dengue fever. The larvae of three Aedes—togoi, macfarlanei and japonicus—possess mouth rakes as well as mouth brushes but whether they are cannibal larvae or not I have not yet been able to ascertain. Aedes togoi has been found in pools in the rocks close to the sea, the other two some distance back from the sea. The principal biting pest is C. fatigans which has been found to carry filarial infection in many parts of the Tropics.
Culicine mosquitoes sent for identification were mainly C. fatigans, Armigeres obturbans, Aedes albopictus.
Mosquito Nuisance Investigation.
Complaints as to mosquito nuisances were received regarding Kowloon Hospital, Major Campbell's quarters, Lugard Road, Police Stations in the New Territories, Lyemun Barracks, Mount Austin Barracks, Pokfulum residences, Cheung Chow Police Station, the neighbourhood of the War Memorial Hospital site at the Peak, and the residence of His Excellency the General Officer Commanding who also complained of a pest of sand flies. Visits were paid to these localities, larval surveys done and recommendations made for abatement of nuisances.
MALARIA INVESTIGATIONS.
Investigations regarding the incidence of Malaria and recommendations bearing on these have been made at the following places during the year:—Capt. Moir's house, Castle Peak Road, New Territories, Taikoo Dockyard, Lyemun Barracks, St. Stephen's College, Stanley Peninsula, Repulse Bay Hotel. Larval surveys have been made at Taipo, Tung Wah Eastern Hospital, Sun Wai Military Camp and around No. 180 the Peak and it is hoped to have these completed at an early date when some further details have been gone into.
Anopheline mosquitoes caught at Lyemun Barracks, Capt. Moir's house and St. Stephen's College Stanley, were identified as follows:—A. maculatus 16, A. hyrcanus 82, A. minimus 18. Most of these were dead on arrival. However, two A. maculatus and ten A. hyrcanus from Stanley were dissected but no infection was found.
In order to obtain information as to infection rates amongst the various Anopheline species, times of feeding, species frequenting houses etc., it will be necessary to train some of the staff to undertake this work,