Tropical Pesticides Research Institute, Division of Livestock and Human Disease Vectors Control, Mosquitoes Section, POBox 3024, Arusha, Tanzania.
Parasit Vectors. 2011 Jul 5;4:129. doi: 10.1186/1756-3305-4-129.
Alternative insecticides for the control of malaria and filarial vectors are of paramount need as resistance is increasing among classes of insecticides currently in use in the public health sector. In this study, mosquitocidal activity of Schinus terebinthifolia essential oil against Anopheles gambiae s.s., An. arabiensis and Culex quinquefasciatus was assessed in laboratory, semi- field and full- field conditions
Twenty third instar larvae of both Anopheles gambiae s.s. and Cx. quinquefasciatus were exposed to different dosages of plant extract in both laboratory and semi- field environments. Observation of the mortality response was assessed at intervals of 12, 24, 48 and 72 hours. Adult semi- gravid female mosquitoes were exposed to papers treated with S. terebinthifolia and compared with WHO standard paper treated with alphacypermethrin (0.05%).
Gas chromatography, coupled to mass spectrometry, identified 15 compounds from S. terebinthifolia extracts, the most abundant identified compound was δ-3-carene (55.36%) and the least was γ-elemene (0.41%). The density of the oil was found to be 0.8086 g/ml. The effective dosages in the insectary ranged from 202.15 to 2625.20 ppm and were further evaluated in the semi- field situation. In the laboratory, the mortality of Cx. quinquefasciatus ranged from 0.5 to 96.75% while for An. gambiae s.s it was from 13.75 to 97.91%. In the semi- field experiments, the mortality rates observed varied for both species with time and concentrations. The LC50 and LC95 value in the laboratory was similar for both species while in the semi- field they were different for each. In wild, adult mosquitoes, the KT50 for S. terebinthifolia was 11.29 minutes while for alphacypermethrin was 19.34 minutes. The 24 hour mortality was found to be 100.0% for S. terebinthifolia and 75.0% for alphacypermethrin which was statistically significant (P < 0.001).
The efficacy shown by essential oils of fruits and seeds of S. terebinthifolia has given an opportunity for further investigation of individual components of these plant extracts and to evaluate them in small- scale field trials.
由于目前公共卫生部门使用的杀虫剂种类的抗药性不断增加，因此急需替代控制疟疾和丝虫病媒介的杀虫剂。在这项研究中，评估了 Schinus terebinthifolia 精油对按蚊属 s.s.、An. arabiensis 和 Culex quinquefasciatus 的杀蚊活性，在实验室、半野外和野外条件下进行。
将 23 龄的 An. gambiae s.s.和 Cx. quinquefasciatus 幼虫暴露于植物提取物的不同剂量下，在实验室和半野外环境中观察死亡率。在 12、24、48 和 72 小时时评估死亡率的变化。将半饱和的成年雌性蚊子暴露在用 S. terebinthifolia 处理的纸上，并与用 alpha-cypermethrin（0.05%）处理的世界卫生组织标准纸进行比较。
气相色谱-质谱联用仪鉴定了 S. terebinthifolia 提取物中的 15 种化合物，最丰富的鉴定化合物是δ-3-蒈烯（55.36%），最少的是γ-榄香烯（0.41%）。油的密度为 0.8086g/ml。昆虫室内的有效剂量范围为 202.15 至 2625.20ppm，并在半野外环境中进行了进一步评估。在实验室中，Cx. quinquefasciatus 的死亡率范围为 0.5%至 96.75%，而 An. gambiae s.s.的死亡率范围为 13.75%至 97.91%。在半野外实验中，两种物种的死亡率随时间和浓度的变化而变化。实验室中两种物种的 LC50 和 LC95 值相似，而半野外的 LC50 和 LC95 值则不同。在野外，成年蚊子的 S. terebinthifolia 的 KT50 为 11.29 分钟，而 alpha-cypermethrin 的 KT50 为 19.34 分钟。24 小时死亡率为 100.0%的 S. terebinthifolia 和 75.0%的 alpha-cypermethrin，差异有统计学意义（P < 0.001）。
Schinus terebinthifolia 的果实和种子精油的功效为进一步研究这些植物提取物的各个成分并在小规模野外试验中进行评估提供了机会。
