Free-range cattle rearing in arid landscapes contributes profoundly to ecosystem degradation. Cattle dung nutrification in aquatic habitats potentially shapes species diversity and abundance due to resource availability. These nutrient-enriched environments may increase oviposition by mosquitoes and influence proliferation of disease vectors. Here, we examined mosquito larval abundance of Culex pipiens pipiens (culicine) and an unidentified Anopheles (anopheline) species across different concentration treatments of nutrient (cattle dung) loadings (T1-T4; 1 g L-1, 2 g L-1, 4 g L-1 and 8 g L-1, respectively) in a randomised outdoor mesocosm experiment. The experiment was run for two weeks post-dung inoculation (Day 7 to 21), with mosquito larvae collected (Day 14 and 21), identified and quantified. Higher dung nutrient concentrations significantly increased mosquito larval abundance relative to dung-free controls. Culicine larvae were 26-times more abundant than anopheline on average. Higher dung concentrations also tended to promote more rapid development in larval mosquitoes. With no colonisation by mosquito larvae in the control treatments, we conclude that the input of dung in aquatic ecosystems promotes vector development and abundance with the potential to increase risk of mosquito-borne infections. We therefore recommend sustainable management policies that tackle likely ecological disservices attributable to free-ranging livestock communities.

中文翻译：

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牛引起的富营养化有利于病媒蚊子。

在干旱地区饲养的放养牛对生态系统的退化有深远的影响。由于资源的可获得性，水生生境中的牛粪营养化有可能影响物种的多样性和丰度。这些营养丰富的环境可能会增加蚊子的产卵并影响疾病媒介的扩散。在这里，我们研究了不同浓度的养分（牛粪）负荷（T1-T4； 1 g L-1、2 g L-1， 4 g L-1和8 g L-1）分别在随机的室外介观实验中进行。该实验在粪便接种后（第7至21天）进行了两周，收集，鉴定并定量了蚊虫幼虫（第14和21天）。相对于不含粪便的对照组，较高的粪便养分浓度显着提高了蚊虫幼虫的丰度。瓜幼虫的平均富集量是按蚊碱的26倍。较高的粪便浓度也倾向于促进幼虫蚊子的更快发育。由于在控制处理中没有蚊虫幼虫的定殖，我们得出结论，水生生态系统中粪便的输入促进了媒介的发展和数量的增加，并有可能增加蚊媒感染的风险。因此，我们建议采取可持续管理政策，以应对因牲畜社区自由放养而可能造成的生态损害。较高的粪便浓度也倾向于促进幼虫蚊子的更快发育。由于在控制处理中没有蚊虫幼虫的定殖，我们得出结论，水生生态系统中粪便的输入促进了媒介的发展和数量的增加，并有可能增加蚊媒感染的风险。因此，我们建议采取可持续管理政策，以应对因牲畜社区自由放养而可能造成的生态损害。较高的粪便浓度也倾向于促进幼虫蚊子的更快发育。由于在控制处理中没有蚊虫幼虫的定殖，我们得出结论，水生生态系统中粪便的输入促进了媒介的发展和数量的增加，并有可能增加蚊媒感染的风险。因此，我们建议采取可持续管理政策，以应对因牲畜社区自由放养而可能造成的生态损害。