Metal pollution is a growing concern that affects the health of humans and animals globally. Copper is an essential insect micronutrient required for respiration, pigmentation and oxidative stress protection but can also act as a potentially toxic trace element. While several studies have focused on the negative fitness effects of copper on the aquatic larvae of mosquitoes, the effects of larval copper exposure on adult mosquito fitness (i.e., survival and fecundity) and their ability to transmit parasites (i.e., vector competence) remains unclear. Here, using a well-studied model vector-parasite system, the mosquito Aedes aegypti and parasite Dirofilaria immitis, we show that sublethal copper exposure in larval mosquitoes alters adult female fecundity and vector competence. Specifically, mosquitoes exposed to copper had a hormetic fecundity response and mosquitoes exposed to 600 μg/L of copper had significantly fewer infective parasite larvae than control mosquitoes not exposed to copper. Thus, exposure of mosquito larvae to copper levels far below EPA-mandated safe drinking water limits (1300 μg/L) can impact vector-borne disease dynamics not only by reducing mosquito abundance (through increased larval mortality), but also by reducing parasite transmission risk. Our results also demonstrated that larval copper is retained through metamorphosis to adulthood in mosquitoes, indicating that these insects could transfer copper from aquatic to terrestrial foodwebs, especially in urban areas where they are abundant. To our knowledge this is the first study to directly link metal exposure with vector competence (i.e., ability to transmit parasites) in any vector-parasite system. Additionally, it also demonstrates unequivocally that mosquitoes can transfer contaminants from aquatic to terrestrial ecosystems. These results have broad implications for public health because they directly linking contaminants and vector-borne disease dynamics, as well as linking mosquitoes and contaminant dynamics.

金属污染是影响全球人类和动物健康的日益关注的问题。铜是呼吸，色素沉着和氧化应激保护所必需的昆虫必需微营养素，但它也可能是潜在的有毒微量元素。尽管一些研究集中在铜对蚊子水生幼虫的负面适应性影响上，但尚不清楚暴露于幼虫铜对成年蚊子适应性（即存活和繁殖力）及其传播寄生虫的能力（即媒介能力）的影响。 。在这里，使用经过充分研究的模型矢量-寄生虫系统，埃及伊蚊和寄生虫Dirofilaria炎，我们显示了幼虫蚊子的亚致死性铜暴露会改变成年雌性繁殖力和媒介能力。具体而言，暴露于铜的蚊子具有旺盛的繁殖力响应，暴露于600μg/ L铜的蚊子的感染性寄生虫幼虫比未暴露于铜的对照蚊子明显少。因此，蚊子幼虫暴露于远远低于EPA规定的安全饮用水限值（1300μg/ L）的铜水平不仅会降低蚊子的丰度（通过增加幼虫死亡率），而且还会通过减少寄生虫传播来影响媒介传播的疾病动态风险。我们的研究结果还表明，幼虫铜通过变质被保留在蚊子中，直至成虫，这表明这些昆虫可以将铜从水生食物网转移到陆地食物网，尤其是在人口丰富的城市地区。据我们所知，这是第一项直接将金属暴露与任何载体-寄生虫系统中的载体能力（即传播寄生虫的能力）联系起来的研究。此外，它还明确表明蚊子可以将污染物从水生生态系统转移到陆地生态系统。这些结果对公共卫生具有广泛的意义，因为它们直接将污染物与媒介传播的疾病动态联系起来，并将蚊子与污染物动态联系起来。