灭蚊幼虫缓释包预防蚊幼虫孳生的现场试验

Efficacy of sustained releasing larvicides package against larval breeding： a field trial

控制中心为试验现场，于2014年7 - 12月，设置20个试验点，每个试验点设4个玻璃瓶（瓶内注入清水和放置富贵竹），分别投放2包、1包灭蚊幼虫缓释包，1%双硫磷颗粒剂3 g 和不采取干预措施，即为高剂量组、低剂量组、阳性对照组和空白对照组。每10 d开展1次现场观察（共19次），记录水体浑浊度、蚊幼虫数量和水生植物损害等情况。在5个固定试验点采集水样，测定其耗氧量、氨氮和有机磷含量。结果 高剂量组、低剂量组、阳性对照组和空白对照组幼虫孳生率分别为0（0／380）、1.1%（4／380）、0.8%（3／380）、63.4%（241／380），植物损害率分别为5.0%（19／380）、5.5%（21／380）、4.7%（18／380）、4.7%（18／380），水体浑浊率分别为24.5%（93／380）、19.7%（75／380）、33.4%（127／380）、20.3%（77／380）。不同处理组幼虫孳生率和水体浑浊率比较差异有统计学意义（χ2 = 823.565、24.715，P均 〈 0.05），水生植物损害率比较差异无统计学意义（χ2 = 0.332，P 〉 0.05）。高剂量组、低剂量组和阳性对照组双硫磷含量分别为1.24、0.78、2.33 mg／L，不同处理组间比较差异有统计学意义（H = 35.426，P 〈 0.01），但耗氧量和氨氮含量比较差异无统计学意义（H = 0.239、0.013，P均 〉 0.05）。结论 灭蚊幼虫缓释包对水体污染少，不影响水体清澈度，未对水生植物造成损害，可有效预防登革热流行期的蚊幼虫孳生。

Objective To evaluate the efficacy of a sustained releasing mosquito larvicide package against larval breeding and its impact on water and plant, in order to provide a scientific evidence for its application in control and prevention of Dengue. Methods Guangzhou Center for Disease Control and Prevention was chosen as the test place. Twenty test sites were set up, 2 bags of sustained releasing larvicides package, 1 bag of sustained releasing larvicides package, 3 g 1% temephos granules and nothing were put into 4 glass bottles for each test site from July to December in 2014, respectively. The 4 glass bottles were called high dose （H） group, low dose （L） group, positive control （P） group and blank control （B） group, respectively. The 4 groups were observed at intervals of 10 days for 19 times. Environmental air temperature, turbidity of water, number of larvae and damage of plant were recorded. And 5 test sites were selected to collect water specimen. The chemical oxygen demand, ammonia nitrogen concentration and temephos concentration of water specimen were detected. Results The larval breeding rates were 0 （0/380）, 1.1% （4/380）, 0.8% （3/380） and 63.4% （241/380）, damage rates of plant were 5.0% （19/380）, 5.5% （21/380）, 4.7% （18/380）, 4.7% （18/380） and turbidty rates of water were 24.5% （93/380）, 19.7% （75/380）, 33.4% （127/380） and 20.3% （77/380） in H, L, P and B groups, respectively. Statistically significant differences were seen in larval breeding rate and turbidity rate of water between different groups （χ2 = 823.565, 24.715, all P 〈 0.05）, but they were not seen in damage rate of plant （χ2 = 0.332, P 〉 0.05）. The temephos concentrations were 1.24, 0.78 and 2.33 mg/L in H, L and P groups, respectively. Statistically significant differences were seen in temephos concentration between different groups （H = 35.426, P 〈 0.01）, but they were not seen in chemical oxygen demand and ammonia nitrogen concentration （H = 0.239, 0.013, all P 〉 0.05）. Conclusions The sustained releasing package of mosquito larvicide makes less pollution to water and has no impact on water turbidity. Moreover, it doesn＇t damage the aquatic plant. The efficacy of the sustained releasing package of mosquito larvicide could effectively prevent mosquito larval breeding in Dengue epidemic period.