Department of Environmental Sciences, Louisiana State University, Baton Rouge, USA.
Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, USA.
J Med Entomol. 2023 May 12;60(3):500-510. doi: 10.1093/jme/tjad018.
Cemetery vases are important habitat for vector mosquito production, yet there is limited understanding on their food web dynamics and how they vary across environmental gradients. Tree cover is one factor that varies widely across cemeteries, and influence food webs by means of detrital inputs, temperature mediation, and light availability. Such information can be important for determining mosquito adult body size, fecundity, and competition outcomes, all of which may influence mosquito population and disease risk. This study evaluates the relationship between tree canopy cover and indicators of basal resources for Aede aegypti (L.), Aedes albopictuss (Skuse), and Culex quinquefasciatus (Say) larvae, such as stable isotopes (δ13C and δ15N) and nutrient stoichiometry in cemeteries of New Orleans, Louisiana (USA). Stable isotope values suggest that larvae feed directly on the Particulate Organic Matter (POM) suspended in the vase's water, and that POM composition influence the nutrient profiles of mosquito larvae. The POM of open canopy vases had higher δ13C values, than that of closed canopy vases indicating differences in relative proportion of basal carbon sources, with open canopy POM having a lower proportion of allochthonous carbon, and a higher proportion of authoctonous carbon. Accordingly, mosquito larvae collected from open canopy vases had higher δ13C values, and higher C:N than larvae from closed canopy vases. The results of this study show a shift in food web dynamics driven by canopy cover in cemetery vases that directly influence the nutrient profiles of mosquito larvae. The implications for mosquito ecology, and vector management are discussed.
公墓花瓶是病媒蚊滋生的重要栖息地，但人们对其食物网动态及其在环境梯度上的变化知之甚少。树木覆盖是公墓中变化很大的一个因素，它通过碎屑输入、温度调节和光照可用性来影响食物网。这些信息对于确定成蚊的体型、繁殖力和竞争结果非常重要，所有这些因素都可能影响蚊子种群和疾病风险。本研究评估了路易斯安那州新奥尔良市公墓树冠覆盖与埃及伊蚊（L.）、白纹伊蚊（Skuse）和库蚊（Culex quinquefasciatus）幼虫基础资源指标之间的关系，如稳定同位素（δ13C 和 δ15N）和营养化学计量学。稳定同位素值表明，幼虫直接以悬浮在花瓶水中的颗粒有机物质（POM）为食，并且 POM 组成影响蚊子幼虫的营养状况。开顶树冠花瓶的 POM 具有较高的 δ13C 值，而闭顶树冠花瓶的 POM 值则表明基础碳源的相对比例存在差异，开顶树冠 POM 的异养碳比例较低，自养碳比例较高。因此，与闭顶树冠花瓶相比，从开顶树冠花瓶收集的蚊子幼虫具有较高的 δ13C 值和较高的 C:N 比。本研究结果表明，公墓花瓶树冠覆盖驱动的食物网动态发生了变化，这直接影响了蚊子幼虫的营养状况。讨论了对蚊子生态学和病媒管理的影响。
