Changing distributions of the cosmopolitan mosquito species <i>Culex quinquefasciatus</i> Say and endemic <i>Cx. pervigilans</i> Bergroth (Diptera: Culicidae) in New Zealand

New Zealand has 13 endemic mosquito species, which are predominantly bird-biters, exhibiting low levels of vector competence, and are adapted to their native ecosystems. Anthropogenic land-use change are well-suited to domesticated exotic species that have already established here. While some endemic species, such as <i>Culex pervigilans,</i> can also be found vutilising such environments, there are indications of population decline and displacement. The cosmopolitan <i>Cx. quinquefasciatus</i> has been established in New Zealand for more than 180 years, and was believed to be confined to the warmer, northern regions. However, biosecurity records of obtained specimens collected by the National Mosquito Surveillance Program, at various points of entry (POE) for goods and international travel, suggest an expansion of this range. Changes in the distributions of <i>Cx. quinquefasciatus</i> and <i>Cx. pervigilans</i> over the last fifteen years in New Zealand, are evaluated herein, with the conclusion that <i>Cx. quinquefasciatus</i> is increasing both in distribution and population density over time, and should be considered an invasive species. Evidence of a southward spread is likely a result of anthropogenic environmental changes particularly favourable to <i>Cx. quinquefasciatus.</i> A trend of considerable ecological and public health importance. Similarly clear effects on urban <i>Cx. pervigilans</i> populations were not observed.

新西兰现有13种特有蚊类，该类群多以鸟类为吸血宿主，媒介效能（vector competence）较低，且已适应本土生态系统。人为土地利用变化更利于已在新西兰定殖的外来归化蚊种。尽管部分特有蚊类（如环跗库蚊（Culex pervigilans））也可在这类人工改造的环境中存续，但已有监测数据显示其种群出现衰退与被排挤的现象。广布种致倦库蚊（Cx. quinquefasciatus）在新西兰定殖已有180余年，此前学界普遍认为其仅局限于气候温暖的北部区域。然而，国家蚊虫监测计划（National Mosquito Surveillance Program）在各类货物与国际入境口岸（points of entry, POE）采集的生物安全样本记录显示，该蚊种的分布范围正持续扩张。本文对过去15年间新西兰致倦库蚊与环跗库蚊的分布变化展开评估，结果表明：致倦库蚊的分布范围与种群密度均随时间推移不断扩大，应将其认定为入侵物种。现有证据显示该蚊正向南扩散，这一现象大概率由人为环境变化所驱动——此类变化恰好为致倦库蚊提供了更适宜的生存条件。该趋势具有显著的生态学与公共卫生重要性。而城市环境中的环跗库蚊种群则未观察到类似的显著变化。