Dose-response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato
Dose-response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato
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DOI：
10.1186/1475-2875-12-94
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发表时间：
2013-03-14
期刊：
影响因子：
3
通讯作者：
Fillinger, Ulrike
中科院分区：
文献类型：
--
作者：
Mbare, Oscar;Lindsay, Steven W.;Fillinger, Ulrike
背景：最近的研究表明，杀幼虫可以成为综合疟疾病媒控制的有效工具。然而，由于需要经常重新使用杀幼虫剂，这种干预措施的采用受到了阻碍。有必要探索持久性、环境友好型杀幼剂来控制疟疾病媒，通过减少使用频率来减少干预工作和成本。在这项研究中，评估了 0.5% 吡丙醚颗粒（Surmilarv (R) 0.5G，住友化学）控制冈比亚按蚊和阿拉伯按蚊（撒哈拉以南非洲地区的主要疟疾病媒）的功效。方法：按照世界卫生组织农药评估计划的标准程序进行剂量反应和标准化现场试验，以确定： (i) 载体对该制剂的敏感性； (ii) 现场应用的残留活性和适当的再处理时间表； (iii) 在幼虫发育过程中接触 SumilarvW0.5G 后，对成虫产卵数量和活力的亚致死影响。 结果：冈比亚按蚊 s.s.和安。 arabiensis 对 SumilarvW0.5G 高度敏感。两个物种的估计羽化抑制 (EI) 值非常低且相似。完全抑制成虫羽化的最小剂量为百万分之 0.01-0.03 活性成分 (ai)。与未处理的对照相比，在标准化田间条件下，施用 0.018 ppm ai 在六周内可阻止 85%（95% 置信区间 (CI) 82%-88%）的成虫羽化。 0.09 ppm ai 剂量增加五倍可阻止 97% (95% CI 94%-98%) 的出苗。在标准化现场测试中观察到显着的亚致死效应。女安.冈比亚船队暴露于 0.018 ppm ai 的幼虫产卵量减少 47%，暴露于 0.09 ppm ai 的雌性比未暴露于处理的雌性产卵量减少 74%。此外，暴露于 0.018 ppm ai 的雌性产下的卵有 77% 未能孵化，而暴露于 0.09 ppm ai 的雌性产下的卵有 98% 未能孵化。和安。 arabiensis 对极低剂量的 Sumilarv (R) 0.5G 高度敏感。这种颗粒制剂在标准化田间条件下经处理的栖息地中的持久性及其亚致死影响，减少了从经处理的池塘中出现的成虫的活卵数量，增强了其作为疟疾媒介控制工具的潜力。这些独特的特性需要进一步的现场测试，以确定其是否适合纳入疟疾媒介控制计划。
Background: Recently research has shown that larviciding can be an effective tool for integrated malaria vector control. Nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. There is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. In this study, the efficacy of a 0.5% pyriproxyfen granule (Surmilarv (R) 0.5G, Sumitomo Chemicals) was assessed for the control of Anopheles gambiae sensu stricto and Anopheles arabiensis, the major malaria vectors in sub-Saharan Africa.Methods: Dose-response and standardized field tests were implemented following standard procedures of the World Health Organization's Pesticide Evaluation Scheme to determine: (i) the susceptibility of vectors to this formulation; (ii) the residual activity and appropriate retreatment schedule for field application; and, (iii) sub-lethal impacts on the number and viability of eggs laid by adults after exposure to SumilarvW0.5G during larval development.Results: Anopheles gambiae s.s. and An. arabiensis were highly susceptible to SumilarvW0.5G. Estimated emergence inhibition (EI) values were very low and similar for both species. The minimum dosage that completely inhibited adult emergence was between 0.01-0.03 parts per million (ppm) active ingredient (ai). Compared to the untreated control, an application of 0.018 ppm ai prevented 85% (95% confidence interval (CI) 82%-88%) of adult emergence over six weeks under standardized field conditions. A fivefold increase in dosage of 0.09 ppm ai prevented 97% (95% CI 94%-98%) emergence. Significant sub-lethal effects were observed in the standardized field tests. Female An. gambiae s.s. that were exposed to 0.018 ppm ai as larvae laid 47% less eggs, and females exposed to 0.09 ppm ai laid 74% less eggs than females that were unexposed to the treatment. Furthermore, 77% of eggs laid by females exposed to 0.018 ppm ai failed to hatch, whilst 98% of eggs laid by females exposed to 0.09 ppm ai did not hatch.Conclusion: Anopheles gambiae s.s. and An. arabiensis are highly susceptible to Sumilarv (R) 0.5G at very low dosages. The persistence of this granule formulation in treated habitats under standardized field conditions and its sub-lethal impact, reducing the number of viable eggs from adults emerging from treated ponds, enhances its potential as malaria vector control tool. These unique properties warrant further field testing to determine its suitability for inclusion in malaria vector control programmes.