USDA-ARS Pollinating Insect - Biology, Management, and Systematics Research Unit, Utah State University, Logan, UT 84322, USA.
Department of Biology and Ecology Center, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA.
J Insect Sci. 2021 Sep 1;21(5). doi: 10.1093/jisesa/ieab065.
Islands are insular environments that are negatively impacted by invasive species. In Hawai'i, at least 21 non-native bees have been documented to date, joining the diversity of >9,000 non-native and invasive species to the archipelago. The goal of this study is to describe the persistence, genetic diversity, and natural history of the most recently established bee to Hawai'i, Megachile policaris Say, 1831 (Hymenoptera: Megachilidae). Contemporary surveys identify that M. policaris is present on at least O'ahu, Maui, and Hawai'i Island, with the earliest detection of the species in 2017. Furthermore, repeated surveys and observations by community members support the hypothesis that M. policaris has been established on Hawai'i Island from 2017 to 2020. DNA sequenced fragments of the cytochrome oxidase I locus identify two distinct haplotypes on Hawai'i Island, suggesting that at least two founders have colonized the island. In their native range, M. policaris is documented to forage on at least 21 different plant families, which are represented in Hawai'i. Finally, ensemble species distribution models (SDMs) constructed with four bioclimatic variables and occurrence data from the native range of M. policaris predicts high habitat suitability on the leeward side of islands throughout the archipelago and at high elevation habitats. While many of the observations presented in our study fall within the predicted habitat suitability on Hawai'i, we also detected the M. policaris on the windward side of Hawai'i Island suggesting that the SDMs we constructed likely do not capture the bioclimatic niche flexibility of the species.
岛屿是受到外来入侵物种负面影响的孤立环境。在夏威夷，迄今为止已有至少 21 种非本地蜜蜂被记录在案，加上 >9000 种非本地和入侵物种，使该群岛的物种多样性更加丰富。本研究的目的是描述最近在夏威夷定居的蜜蜂 Megachile policaris Say, 1831（膜翅目：Megachilidae）的持久性、遗传多样性和自然历史。当代调查表明，M. policaris 至少存在于瓦胡岛、毛伊岛和夏威夷岛，该物种最早于 2017 年被发现。此外，社区成员的重复调查和观察支持了以下假设：自 2017 年以来，M. policaris 已经在夏威夷岛上建立了种群。COI 基因座的 DNA 测序片段在夏威夷岛上识别出两个不同的单倍型，表明至少有两个殖民者已经在该岛上定居。在其原生范围内，M. policaris 被记录在案，以至少 21 种不同的植物科为食，而这些植物科在夏威夷都有代表。最后，使用来自 M. policaris 原生范围的四个生物气候变量和出现数据构建的综合物种分布模型（SDM）预测，该群岛背风侧和高海拔栖息地的栖息地适宜度很高。虽然我们的研究中提出的许多观察结果都在预测的夏威夷栖息地适宜度范围内，但我们也在夏威夷岛的迎风侧检测到了 M. policaris，这表明我们构建的 SDM 可能无法捕捉到该物种的生物气候生态位灵活性。
