The most effective pollinator principle applies to new invasive pollinators

G.L. Stebbins’ most effective pollinator principle states that when pollinators are not limiting, plants are expected to specialize and adapt to the more abundant and effective pollinator species available. In this study, we quantify the effectiveness of bees, hummingbirds and hawkmoths in a Chilean population of Erythranthe lutea (Phrymaceae), and examine whether flower traits are subject to pollinator-mediated selection by the most effective pollinator species during two consecutive years. Unlike most species in the pollinator community, the visitation rate of the recently arrived Bombus terrestris did not change substantially between years, which together its high and stable pollen delivery to flower stigmas made this species the most important in the pollinator assemblage followed by the solitary bee Centris nigerrima. Flower traits were under significant selection in the direction expected for short-tongue bees, suggesting that E. lutea is in the initial steps of adaptation to the ...

G.L. 斯泰宾斯提出的最有效传粉者原则（most effective pollinator principle）指出，当传粉者资源不受限时，植物将发生特化并适应现有种群中数量更丰富、传粉效率更优异的传粉者物种。本研究针对智利境内的黄花沟酸浆（Erythranthe lutea，Phrymaceae）种群，量化了蜜蜂、蜂鸟与天蛾的传粉效率，并探究连续两年间，花部性状是否受到优势传粉者物种的传粉介导选择。与传粉者群落中的多数物种不同，新近入侵的大地熊蜂（Bombus terrestris）的访花频率在两年间并未出现显著变化，加之其对花柱头的花粉传递效率高且稳定，使其成为该传粉者群落中最为关键的物种，紧随其后的则是独居蜂黑暗尖腹蜂（Centris nigerrima）。花部性状受到显著选择，且选择方向符合短舌蜂的适配预期，这表明黄花沟酸浆正处于适应……的初始阶段。