广东城镇地区防治蚊虫试验

本文以20%除虫脲(即灭幼脲Ⅰ号)胶悬剂在广东省番禺县大岗镇地区进行防治蚊幼虫试验.结果表明,根据蚊种及其孽生地类型可施用0.1—1.0ppm的浓度,对白纹伊蚊、致倦库蚊和骚扰阿蚊幼虫都有比较好的效果,而且持效也比较长.经过每15—20天喷洒一次,防治面积共564m²,基本上控制了蚊虫的发生数量.通过诱蚊箱的监测,7—9月份处理区各月份的成蚊密度均比对照区低.在使用剂量的范围内,除虫脲对鲩鱼、鳙鱼、食蚊鱼和蝌蚪安全.其杀虫作用是抑制幼虫的生长发育和变态.

EXPERIMENTS ON MOSQUITO CONTROL IN A TOWN DISTRICT OF GUANGDONG PROVINCE

Field experiments were carried out in a town district of Guangdong Province by using 20% suspension of diflubenzuron (DFBZ) to control mosquitoes in their breeding sites. The results showed that the average larval populations of Culex quinquejasciatus in the breeding water bodies were reduced 78% and 99% as compared with the control on the third day and the seventh day respectively after spraying the diluted DFBZ to a final concentration of 0.5 ppm. The residual effect extended over a long period and morphological abnormalities were observed in emerged adult mosquitoes which adhered to pupal exuviae and died on the water surface on the 19th to 25th days after spraying. DFBZ appeared to have a long lasting effect in the mosquito breeding sites; spraying DFBZ suspension to polluted drains to concentration 0.5-1.0 ppm would suppress larval populations of C. quinquejasciatus effectively and the average population density of the adults in the treated area was reduced to half that of the untreated area. DFBZ was also effective to control other mosquitoes including Aedes albo-picius and Armigers subalbatus in their breeding sites with the same method. DFBZ in effective dosage to mosquitoes was safe to tadpoles and fishes such as Ctenopharyngodon idellus and Aristichthys nobilis.