Lothrop Hugh, Lothrop Branka, Palmer Mark, Wheeler Sarah, Gutierrez Arturo, Gomsi Donald, Reisen William K
Center for Vectorborne Diseases and the Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Old Davis Road, Davis, CA 95616, USA.
J Am Mosq Control Assoc. 2007 Jun;23(2):190-207. doi: 10.2987/8756-971X(2007)23[190:EOPAPG]2.0.CO;2.
Six experimental ground ultra-low volume (ULV) applications of Pyrenone 25-5 (0.0025 lb/acre) and Aqua-Reslin (0.007 lb/acre) were made by truck-mounted Pro-Mist or London Fog equipment over 1-mi2 study areas in rural and residential environments of the Coachella Valley, Riverside County, California. Efficacy of replicate applications was evaluated by measuring mortality among caged sentinel mosquitoes, by evaluating changes in host-seeking abundance at replicated dry ice-baited traps positioned along intersecting east-west and north-south transects, and by differential recapture patterns of marked females released near traps in the sprayed central core and unsprayed control areas. Sentinel mortality agreed well with estimates of droplet density measured by "slide spinners" and was affected by 1) distance of cages from the truck route; 2) landscape features, such as tree lines that created wind shadows; 3) irregular landscape that disrupted the particle cloud; 4) low wind speed that failed to carry the droplet cloud through the environment; and 5) failure of the droplets to penetrate dead airspace within stands of vegetation. Despite variable sentinel mortality, Culex tarsalis relative abundance in rural landscapes within and around our study areas always declined after ULV applications. Concurrent decreases in abundance at traps within sprayed and adjoining unsprayed areas confounded our estimates of percentage of control using Mulla's formula, which compares abundance in sprayed and unsprayed areas pre- and postspray. ULV applications significantly affected recapture patterns, in that recapture rates within the spray zone usually were significantly less than in the unsprayed zone. Collectively, our data indicated that ground ULV applications measurably reduced Cx. tarsalis abundance in rural areas of the Coachella Valley but that further evaluations may be necessary to validate efficacy on Culex quinquefasciatus populations in residential communities.
使用安装在卡车上的Pro-Mist或London Fog设备，在加利福尼亚州河滨县科切拉谷的农村和居住环境中，对1平方英里的研究区域进行了6次实验性地面超低容量（ULV）喷雾，分别使用了25-5除虫菊酯（0.0025磅/英亩）和Aqua-Reslin（0.007磅/英亩）。通过测量笼养哨兵蚊子的死亡率、评估沿东西向和南北向相交样带设置的重复干冰诱捕器上宿主寻找丰度的变化，以及通过在喷雾中心核心区和未喷雾对照区附近诱捕器附近释放的标记雌蚊的差异回收模式，来评估重复喷雾的效果。哨兵死亡率与通过“载玻片旋转器”测量的液滴密度估计值非常吻合，并且受到以下因素的影响：1）笼子与卡车路线的距离；2）景观特征，如形成风影的林带；3）扰乱粒子云的不规则景观；4）未能将液滴云携带通过环境的低风速；5）液滴未能穿透植被林分内的静止空气层。尽管哨兵死亡率存在差异，但在我们研究区域内及周边农村景观中，致倦库蚊的相对丰度在ULV喷雾后总是下降的。喷雾区内和相邻未喷雾区诱捕器处丰度的同时下降，混淆了我们使用穆拉公式对防治百分比的估计，该公式比较喷雾前后喷雾区和未喷雾区的丰度。ULV喷雾显著影响回收模式，即喷雾区内的回收率通常显著低于未喷雾区。总体而言，我们的数据表明，地面ULV喷雾可显著降低科切拉谷农村地区致倦库蚊的丰度，但可能需要进一步评估，以验证对居民区致乏库蚊种群的防治效果。
