Assessment of Culex pipiens bioforms in the world’s southernmost distribution limit

The mosquito Culex pipiens s.s. L. occurs as two bioforms that differ in physiology and behaviour affecting virus transmission cycles. To assess the occurrence of Cx. pipiens bioforms in the southernmost limit of its distribution, specimens were collected aboveground in southern Buenos Aires Province and east Patagonia, Argentina. Ten larvae and 25 adults were individually processed and identified by polymerase chain reaction (PCR) amplification of Ace-2 and CQ11 loci. Culex quinquefasciatus Say (one larva, two adults), Cx. pipiens f. molestus (one larva, one adult) and one adult of hybrid origin were identified in Buenos Aires Province; only Cx. pipiens f. molestus was recorded in Patagonia (eight larvae, 21 adults). The potential absence of bioform pipiens and its implications in arbovirus enzootic cycles is discussed.

尖音库蚊指名亚种（Culex pipiens s.s. L.）可分为两种生物型，二者在影响病毒传播循环的生理与行为特征上存在显著差异。为评估该物种分布最南端区域内尖音库蚊生物型的存在情况，研究人员在阿根廷布宜诺斯艾利斯省南部与东巴塔哥尼亚地区的地上生境采集了标本。研究对10头幼虫与25头成蚊分别进行个体处理，并通过Ace-2与CQ11基因座的聚合酶链式反应（PCR）扩增完成物种鉴定。在布宜诺斯艾利斯省，共鉴定出致倦库蚊（Culex quinquefasciatus Say，1头幼虫、2头成蚊）、尖音库蚊骚扰型（Cx. pipiens f. molestus，1头幼虫、1头成蚊）以及1头杂交起源成蚊；而在巴塔哥尼亚地区仅记录到尖音库蚊骚扰型（8头幼虫、21头成蚊）。本研究还探讨了尖音库蚊pipiens生物型可能缺失的现象，及其对虫媒病毒地方性循环的潜在影响。