Westreich Lila R, Westreich Samuel T, Tobin Patrick C
School of Environmental and Forest Sciences, University of Washington, 3715 W. Stevens Way NE, Seattle, WA, 98195, USA.
DNAnexus Inc., 1975 El Camino Real, Mountain View, CA, 94041, USA.
Oecologia. 2023 Apr;201(4):965-978. doi: 10.1007/s00442-023-05354-5. Epub 2023 Mar 22.
Spring-emerging bees depend upon the synchronized bloom times of angiosperms that provide pollen and nectar for offspring. The emergence of such bees and bloom times are linked to weather but can be phenologically mismatched, which could limit bee developmental success. However, it remains unclear how such phenologically asynchrony could affect spring-emerging pollinators, and especially for those that forage over a relatively short time period. We examined the relationship between weather and host plant selection on the native spring-foraging solitary bee, Osmia lignaria, across 3 years at urban and rural sites in and around Seattle, Washington, USA. We used community science weather data to test the effects of precipitation, wind, and temperature on O. lignaria oviposition and developmental success. We also collected pollen data over two distinct foraging periods, early and late spring, and used Next-Generation Sequencing to identify plant genera from pollen. Among the weather variables, precipitation during the early foraging period adversely affected larval developmental success and adult bee emergence success, but not oviposition. Using DNA metabarcoding, we observed that increases in the number of plant genera in pollen increased adult emergence in both foraging periods, but not oviposition or larval development. We also observed that foraging bees consistently visited certain genera during each foraging period, especially Acer, Salix, and Rubus. However, pollen collected by O. lignaria over different years varied in the number of total genera visited, highlighting the importance of multi-year studies to ascertain bee foraging preferences and its link to developmental success.
春季出现的蜜蜂依赖被子植物同步的开花时间，这些被子植物为后代提供花粉和花蜜。此类蜜蜂的出现时间与开花时间都与天气有关，但在物候上可能不匹配，这可能会限制蜜蜂的发育成功率。然而，目前尚不清楚这种物候异步如何影响春季出现的传粉者，尤其是那些觅食时间相对较短的传粉者。我们在美国华盛顿州西雅图市及其周边的城市和农村地区，对本土春季觅食的独居蜜蜂——木蜂（Osmia lignaria），进行了为期3年的研究，考察天气与宿主植物选择之间的关系。我们使用社区科学天气数据，来测试降水、风和温度对木蜂产卵及发育成功率的影响。我们还在早春和晚春两个不同的觅食期收集了花粉数据，并使用下一代测序技术从花粉中鉴定植物属。在天气变量中，早期觅食期的降水对幼虫发育成功率和成年蜜蜂出现成功率有不利影响，但对产卵没有影响。通过DNA宏条形码分析，我们观察到花粉中植物属数量的增加，在两个觅食期都提高了成年蜜蜂的出现率，但对产卵或幼虫发育没有影响。我们还观察到，觅食的蜜蜂在每个觅食期都始终会访问某些属的植物，尤其是槭属、柳属和悬钩子属。然而，不同年份木蜂采集的花粉中，所访问的植物属总数有所不同，这凸显了多年研究对于确定蜜蜂觅食偏好及其与发育成功率之间联系的重要性。
