Data from: Divergent host preferences of above- and below-ground Culex pipiens (Diptera: Culicidae) and their hybrid offspring.

Culex pipiens form pipiens and Cx. pipiens form molestus (Diptera: Culicidae) belong to a cosmopolitan taxonomic group known as the Pipiens Assemblage. Hybridization between these forms is thought to contribute to human transmission of West Nile virus (WNV) in North America. Complementary choice and no-choice landing assays were developed to examine host acceptance by North American Cx. pipiens in the laboratory. Populations collected from above- and below-ground sites in suburban Chicago were identified as forms pipiens and molestus using a polymerase chain reaction-based assay. Avian and human host acceptance was then quantified for the two populations, as well as for their hybrid and backcross offspring. No-choice tests were used to demonstrate that both the pipiens and molestus forms were capable of feeding on human and avian hosts. Choice tests were used to demonstrate that form pipiens females were strongly avian-seeking; an individual's probability of accepting the chick host was 85%. Form molestus females were more likely to accept the human host (87%). Rates of host acceptance by F1 and backcross progeny were intermediate to those of their parents. The results suggest that host preferences in Cx. pipiens are genetically determined, and that ongoing hybridization between above- and below-ground populations is an important contributor to epizootic transmission of WNV in North America.

尖音库蚊pipiens型（Culex pipiens form pipiens）与尖音库蚊molestus型（Cx. pipiens form molestus，双翅目Diptera: 蚊科Culicidae）隶属于一个广布的分类类群——尖音复合群（Pipiens Assemblage）。学界普遍认为，这两个型之间的杂交事件，是北美地区西尼罗河病毒（West Nile virus, WNV）经蚊媒传播给人类的重要促成因素。

本研究开发了双向选择与非选择停落试验，以在实验室环境下探究北美尖音库蚊的宿主接受行为。研究人员从芝加哥郊区的地上与地下生境中采集了种群样本，并通过基于聚合酶链式反应（polymerase chain reaction, PCR）的鉴定方法，将样本分别归类为pipiens型与molestus型。随后，针对这两个亲本种群、二者的子一代（F1）杂交后代以及回交后代，分别量化了其对禽类与人类宿主的接受率。

非选择试验结果显示，pipiens型与molestus型尖音库蚊均能够取食人类与禽类宿主。双向选择试验结果表明，pipiens型雌蚊具有强烈的禽类宿主偏好：其选择雏鸡宿主的概率高达85%。而molestus型雌蚊则更倾向于选择人类宿主，选择率为87%。子一代及回交后代的宿主接受率均介于两个亲本种群之间。

本研究结果提示，尖音库蚊的宿主偏好由遗传因素决定，而地上与地下生境种群间持续发生的杂交事件，是北美地区西尼罗河病毒流行性传播的重要驱动因素之一。