Friesen Kristina M, Johnson Gregory D
Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA.
J Am Mosq Control Assoc. 2013 Jun;29(2):102-7. doi: 10.2987/12-6323R.1.
Mortality of American white pelican (Pelecanus erythrorhynchos) chicks attributed to West Nile virus (WNV) prompted field studies on the bionomics of mosquitoes on a wildlife refuge in northern Montana. One component of these studies was to identify blood meal sources for Culex tarsalis, the primary vector of WNV in the region, and the potential bridge vectors Aedes vexans and Culiseta inornata. To accomplish this, 3 methods were evaluated to collect bloodfed mosquitoes: a gasoline powered aspirator, CO2-baited light traps, and fiber pots in shelterbelts consisting of stands of deciduous trees and shrubs and marshes along the lake edge. Fiber pots were also deployed in open fields of prairie grasses. Overall, fiber pots were the most efficient method for collecting engorged Cx. tarsalis and Cs. inornata, largely due to shorter sampling and processing times. Aedes vexans was not collected in fiber pots but was more abundant in aspiration samples than the other 2 species. The optimal location for collecting Cx. tarsalis was dependent on trapping method. Aspirations and fiber pot placements collected more Cx. tarsalis in shelterbelts, while CO2-baited light traps collected more Cx. tarsalis in the marsh habitat. Sixteen avian and 4 mammalian hosts were identified from bloodfed Cx. tarsalis with 46 blood meals derived from birds and 49 from mammals. Aedes vexans and Cs. inornata fed predominantly on white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus), respectively. Humans were identified as hosts in 33% of engorged Cx. tarsalis, 4% of engorged Ae. vexans, and 18% of engorged Cs. inornata.
西尼罗河病毒（WNV）导致美国白鹈鹕（Pelecanus erythrorhynchos）雏鸟死亡，促使人们在蒙大拿州北部的一个野生动物保护区对蚊子的生物习性展开实地研究。这些研究的一个组成部分是确定该地区WNV的主要传播媒介——致倦库蚊（Culex tarsalis）以及潜在的桥梁媒介——骚扰伊蚊（Aedes vexans）和无饰库蚊（Culiseta inornata）的血餐来源。为实现这一目标，评估了3种收集吸食血液蚊子的方法：汽油动力吸气器、二氧化碳诱捕灯以及位于由落叶乔木和灌木林带以及湖边沼泽地组成的防风林中的纤维罐。纤维罐也被放置在长满草原草的开阔田野中。总体而言，纤维罐是收集饱血致倦库蚊和无饰库蚊最有效的方法，这主要是因为采样和处理时间较短。骚扰伊蚊未在纤维罐中被收集到，但在吸气样本中比其他两个物种更为常见。收集致倦库蚊的最佳地点取决于诱捕方法。吸气法和纤维罐放置法在防风林中收集到更多的致倦库蚊，而二氧化碳诱捕灯在沼泽栖息地收集到更多的致倦库蚊。从饱血的致倦库蚊中鉴定出16种鸟类宿主和4种哺乳动物宿主，其中46份血餐来自鸟类，49份来自哺乳动物。骚扰伊蚊和无饰库蚊分别主要以白尾鹿（Odocoileus virginianus）和牛（Bos taurus）为食。在33%的饱血致倦库蚊、4%的饱血骚扰伊蚊和18%的饱血无饰库蚊中鉴定出人类为宿主。
