Murray Anne F, Leonhardt Sara D, Stout Jane C, Ruedenauer Fabian A, Vanderplanck Maryse, Russo Laura
Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA.
Plant-Insect-Interactions, TUM School of Life Sciences, Technische Universität München, Freising, Germany.
J Chem Ecol. 2025 Jan 24;51(1):7. doi: 10.1007/s10886-025-01552-y.
Pollinators help maintain functional landscapes and are sensitive to floral nutritional quality. Both proteins and lipids influence pollinator foraging, but the role of individual biochemical components in pollen remains unclear. We conducted an experiment comprising common garden plots of six plant species (Asteraceae, Rosaceae, Onagraceae, Boraginaceae, and Plantaginaceae). These plots were treated with low concentrations of agrochemicals, including fertilizer, herbicide, and a combination of both to induce intra-specific variation in floral chemistry. We recorded insect visitation to inflorescences over two years and eight sites in Dublin, Ireland. We analyzed the pollen amino acid and fatty acid content, quantifying the concentrations of 51 fatty acids and 17 amino acids of the six focal plant species across the four agrochemical treatments. We tested relationships between the pollen composition and the insect visitation matrix as well as an insect trait matrix including sociality, body size, nesting behavior, and whether the insect was a bee or hoverfly. We found: (i) the agrochemical treatments did not affect the biochemical composition of the pollen; (ii) there were many strong associations between fatty acids, amino acids, insect traits, and visitation; and (iii) specific compounds with strong associations (montanic acid, cysteine, and proline) explained more of the variance in insect abundance (honeybees, bumble bees, and hoverflies) than the total amino acid or fatty acid concentrations in the pollen. Our results suggest it is important to evaluate the contribution of individual biochemical compounds in pollen to insect visitation, and also that different insect species respond to different pollen compounds.
传粉者有助于维持功能性景观，且对花的营养质量敏感。蛋白质和脂质都会影响传粉者的觅食行为，但花粉中单个生化成分的作用仍不清楚。我们进行了一项实验，设置了六种植物（菊科、蔷薇科、柳叶菜科、紫草科和车前科）的普通园圃。这些园圃用低浓度的农用化学品处理，包括肥料、除草剂以及两者的组合，以诱导花的化学组成发生种内变异。我们在爱尔兰都柏林的八个地点记录了两年内昆虫对花序的访花情况。我们分析了花粉的氨基酸和脂肪酸含量，量化了六种目标植物在四种农用化学品处理下51种脂肪酸和17种氨基酸的浓度。我们测试了花粉组成与昆虫访花矩阵以及昆虫特征矩阵（包括社会性、体型、筑巢行为以及昆虫是蜜蜂还是食蚜蝇）之间的关系。我们发现：（i）农用化学品处理不影响花粉的生化组成；（ii）脂肪酸、氨基酸、昆虫特征和访花之间存在许多强关联；（iii）具有强关联的特定化合物（褐煤酸、半胱氨酸和脯氨酸）比花粉中的总氨基酸或脂肪酸浓度能解释更多昆虫（蜜蜂、大黄蜂和食蚜蝇）数量的变异。我们的结果表明，评估花粉中单个生化化合物对昆虫访花的贡献很重要，而且不同昆虫物种对不同的花粉化合物有不同反应。
