Hawaii has a single group of native bees belonging to the genus Hylaeus (Hymenoptera: Colletidae) and known collectively as Hawaiian yellow-faced bees. The majority of the 63 species have experienced significant declines in range and population. In 2016, seven species received federal protection under the Endangered Species Act of 1973. Competitors and predators, such as invasive bees, wasps and ants, are thought to be important drivers of range reductions and population declines, especially at lower elevations where more non-native species occur. We evaluated the effects of invasive ants on nesting Hylaeus anthracinus using artificial nest blocks that allowed us to track nest construction and development. The blocks were placed in pairs at 22 points encompassing three sites on the north and east sides of Oahu. One block in each pair was treated with a sticky barrier to prevent access by ants, while the other block remained untreated. From December 2015 to December 2016, we monitored 961 individual nests in the blocks. Seventy percent of nests in control blocks were invaded by ants. Nests in treated blocks were more likely to produce at least one adult than nests in untreated blocks (38% vs. 14%, respectively). In untreated blocks, ants were the most common cause of nest mortality followed by lack of development, displacement (primarily by the competitor Pachodynerus nasidens) and presumed pathogens. The invasive ant, Ochetellus glaber was the only observed nest predator, although the big-headed ant, Pheidole megacephala was also present. Hylaeus anthracinus inhabits coastal strand habitat which occurs in a narrow band just above the high tide line. Nests at one site were destroyed due to a high wave event, highlighting this species’ vulnerability to sea level rise. Additionally, no adult bees or nests were observed at the points where yellow crazy ants, Anoplolepis gracilipes were established. An increased understanding of the factors limiting Hawaii’s yellow-faced bees will provide information for future conservation efforts that may include landscape-scale ant control, habitat restoration and translocations.

中文翻译：

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入侵性蚂蚁减少了濒临灭绝的夏威夷黄蜂蜜蜂Hylaeus anthracinus的筑巢成功

夏威夷只有一组土生蜂，属于Hylaeus属（膜翅目：Colletidae），被统称为夏威夷黄面蜂。63个物种中的大多数经历了范围和种群的大幅下降。2016年，根据1973年《濒危物种法》，七种物种获得了联邦保护。竞争者和掠食者，例如入侵性蜜蜂，黄蜂和蚂蚁，被认为是缩小范围和减少种群数量的重要推动力，尤其是在海拔较低的地方，非发生本地物种。我们使用人工筑巢块评估了侵入性蚂蚁对筑巢鬣狗的影响，这使我们能够跟踪筑巢和发育。这些街区成对放置在22个点上，涵盖了瓦胡岛北侧和东侧的三个地点。每对中的一块用粘性屏障处理，以防止蚂蚁进入，而另一块未处理。从2015年12月到2016年12月，我们监测了这些街区中的961个独立巢穴。控制箱中有70％的巢被蚂蚁入侵。与未处理块相比，处理过的块中的巢更可能产生至少一个成年个体（分别为38％和14％）。在未经处理的地块中，蚂蚁是造成巢内死亡的最常见原因，其次是缺乏发育，移位（主要是由竞争者纳希菌（Pachodynerus nasidens）引起）和推测的病原体。入侵性蚂蚁Ochetellus glaber是唯一观察到的巢捕食者，尽管也有大头蚂蚁Pheidole megacephala。Hylaeus anthracinus栖息于沿海链栖息地，该栖息地出现在高潮线上方的一条狭窄带中。一个地点的巢穴由于一场高潮事件而被摧毁，突显了该物种对海平面上升的脆弱性。此外，在建立黄色疯狂蚂蚁，无芒线虫的地方没有观察到成年蜜蜂或巢。对限制夏威夷黄脸蜂的因素的进一步了解将为今后的保护工作提供信息，包括景观规模的蚂蚁控制，栖息地恢复和易位。