Abstract Aedes albopictus has replaced Aedes aegypti in much of the latter species’ historic range within the United States. The leading hypothesis for this displacement is exclusion via resource competition; however, the proximate mechanism producing a competitive advantage for A. albopictus over A. aegypti has not been identified. We performed laboratory experiments to test the hypotheses that these species differ in feeding behavior, and that these differences result in differences in survival when resources are scarce. Differences in feeding behavior were assessed in three environments with food (growing microorganisms) available: 1) in fluid only; 2) on leaf surfaces only; 3) or both in fluid and on leaf surfaces. We determined behavior of larvae in these environments, recording their positions (bottom, wall, leaf, top, or middle) and activities (browsing, filtering, resting, or thrashing) using instantaneous scan censuses. A. albopictus spent significantly more time at leaf surfaces, whereas A. aegypti spent more time engaging in nonfeeding activities. Both species showed a significant shift in foraging activity toward leaves when leaves were available. In a second experiment, we recorded survivorship for individuals raised in two treatment combinations: whole or half 17-mm disks of live oak leaves, with or without direct access to the leaf surface (controlled using nylon mesh, which allowed movement of microscopic organisms, but prevented mosquito larva movement between container sides). After 31 d, survivorship of A. albopictus was significantly greater than that of A. aegypti regardless of treatments. Moreover, A. albopictus showed significantly greater survivorship compared with A. aegypti when deprived of access to leaf surfaces and in whole leaf disk treatments, suggesting superior resource-harvesting ability for A. albopictus. Our experiments suggest that differences in foraging behavior contribute to the competitive advantage of A. albopictus over A. aegypti that has been observed in North America.

中文翻译：

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白纹伊蚊幼虫和埃及伊蚊幼虫（双翅目：虱科）在食物限制条件下摄食行为和存活的种间差异

摘要 Aedes albopictus 已在美国境内大部分埃及伊蚊的历史范围内取代了埃及伊蚊。这种置换的主要假设是通过资源竞争进行排斥；然而，A. albopictus 比 A. aegypti 产生竞争优势的直接机制尚未确定。我们进行了实验室实验，以检验这些物种在摄食行为上存在差异的假设，以及这些差异导致资源稀缺时生存差异的假设。在三种有食物（生长微生物）的环境中评估摄食行为的差异：1）仅在流体中；2) 仅在叶子表面；3) 或同时存在于流体和叶表面。我们确定了幼虫在这些环境中的行为，记录了它们的位置（底部、墙壁、叶子、顶部、或中间）和活动（浏览、过滤、休息或颠簸）使用即时扫描普查。A. albopictus 在叶子表面花费的时间明显更多，而 A. aegypti 花费更多时间从事非摄食活动。当叶子可用时，这两个物种都显示出觅食活动向叶子的显着转变。在第二个实验中，我们记录了在两种处理组合中饲养的个体的存活率：整个或半个 17 毫米的活橡树叶圆盘，有或没有直接接触叶面（使用尼龙网控制，允许微生物移动，但防止蚊子幼虫在容器两侧之间移动）。31 天后，白纹伊蚊的存活率显着高于埃及伊蚊，无论治疗如何。此外，A. 与 A. aegypti 相比，当被剥夺进入叶表面和在整个叶盘处理中时，albopictus 显示出显着更高的存活率，这表明 A. albopictus 具有优越的资源收获能力。我们的实验表明，觅食行为的差异有助于在北美观察到 A. albopictus 相对于 A. aegypti 的竞争优势。