Alto Barry W, Bettinardi David J, Ortiz Sara
Corresponding author, e-mail:
Department of Entomology and Nematology, University of Florida, IFAS, Florida Medical Entomology Laboratory, 200 9th St. S.E. Vero Beach, FL 32962Corresponding author, e-mail:
J Med Entomol. 2015 Mar;52(2):163-70. doi: 10.1093/jme/tju062. Epub 2015 Feb 9.
Mosquitoes often experience intraspecific and interspecific competition among larvae attributable to high densities and nutrient limitation, especially container mosquitoes including Aedes aegypti (L.) and Aedes albopictus (Skuse). Density-dependent effects on larvae impact adult production and adult traits that influence transmission of arboviruses. To improve our understanding of the mechanisms by which density-dependence influences transmission and identify species-specific traits, we tested the hypotheses: 1) Competitive asymmetry in favor of Ae. albopictus over Ae. aegypti translates to altered adult female survival, and 2) Ae. aegypti adult females are more resistant to life-shortening effects of low-humidity conditions than Ae. albopictus. We gauged the relative impact of inter- and intraspecific larval competition on adult survival in high- and low-humidity regimes (77 and 44% relative humidity, respectively). For Ae. albopictus, intraspecific but not interspecific competition usually reduced adult survival under both humidity regimes. For Ae. aegypti, both intraspecific and interspecific competition reduced adult survival. Ae. albopictus adult survival was minimally influenced by interspecific competition with Ae. aegypti, consistent with observations that Ae. albopictus is the superior competitor. A species comparison indicated that Ae. aegypti exhibited a survival advantage relative to Ae. albopictus under both low- and high-humidity conditions. However, similar survival of these Aedes species was observed in some cases depending on conditions experienced in both the aquatic and terrestrial environments. These results demonstrate plasticity in survival rates of dengue and chikungunya vectors and the significance of considering the influence of biological interactions during the immature stages and abiotic conditions during the adult stage.
由于高密度和营养限制，蚊子幼虫经常经历种内和种间竞争，尤其是包括埃及伊蚊（L.）和白纹伊蚊（Skuse）在内的容器型蚊子。幼虫的密度依赖性效应会影响成虫的产生以及影响虫媒病毒传播的成虫特征。为了更好地理解密度依赖性影响传播的机制并确定物种特异性特征，我们检验了以下假设：1）白纹伊蚊相对于埃及伊蚊的竞争不对称性转化为成年雌蚊存活率的改变；2）埃及伊蚊成年雌蚊比白纹伊蚊更能抵抗低湿度条件下的寿命缩短效应。我们评估了种内和种间幼虫竞争在高湿度和低湿度环境（相对湿度分别为77%和44%）下对成虫存活的相对影响。对于白纹伊蚊，在两种湿度环境下，种内竞争而非种间竞争通常会降低成虫存活率。对于埃及伊蚊，种内和种间竞争都会降低成虫存活率。白纹伊蚊的成虫存活受与埃及伊蚊种间竞争的影响最小，这与白纹伊蚊是优势竞争者的观察结果一致。物种比较表明，在低湿度和高湿度条件下，埃及伊蚊相对于白纹伊蚊都表现出存活优势。然而，在某些情况下，根据水生和陆生环境中所经历的条件，观察到这两种伊蚊的存活率相似。这些结果表明登革热和基孔肯雅热媒介的存活率具有可塑性，以及在未成熟阶段考虑生物相互作用和成虫阶段非生物条件影响的重要性。
