Cephalaria transsylvanica-Based Flower Strips as Potential Food Source for Bees during Dry Periods in European Mediterranean Basin Countries

The introduction of sown wildflower strips favours the establishment of pollinator communities, with special reference to social Apoidea. Here, we evaluated the late summer flowering Cephalaria transsylvanica as suitable species for strips providing food for pollinators in paucity periods. C. transsylvanica showed no particular requirements in terms of seed germination and growth during summer. This plant had an excellent potential of self-seeding and competitiveness towards weed competitors. C. transsylvanica prevented from entomophilous pollination showed inbreeding depression, with a decrease in seed-set and accumulation of seed energy reserves. However, C. transsylvanica did not appear to be vulnerable in terms of pollination biology since it had a wide range of pollinators including bees, hoverflies and Lepidoptera. C. transsylvanica was visited mainly by honeybees and bumblebees and these latter pollinators increased their visits on C. transsylvanica flowers during early autumn. This plant may be useful as an abundant source of pollen during food paucity periods, such as autumn. We proposed C. transsylvanica for incorporation into flower strips to be planted in non-cropped farmlands in intensively managed agricultural areas as well as in proximity of beehives. The latter option may facilitate the honeybees collecting pollen and nectar for the colony, thereby ensuring robustness to overcome the winter season.播种野生花卉带的构建可有效促进传粉者群落的建立，尤其对社会性蜜蜂总科（Apoidea）类群意义显著。本研究以夏末开花的外高加索刺萼参（Cephalaria transsylvanica）为对象，评估其作为食物匮乏期传粉者蜜源植物的应用潜力。该物种在夏季的种子萌发与生长过程中无特殊生境需求，且具备优异的自播能力与杂草竞争优势。当外高加索刺萼参被阻断虫媒传粉（entomophilous pollination）时，会出现近交衰退现象，表现为结籽率下降与种子能量储备积累不足。但从传粉生物学视角分析，该物种并未呈现传粉脆弱性：其访花传粉者类群广泛，涵盖蜂类、食蚜蝇与鳞翅目（Lepidoptera）昆虫。外高加索刺萼参的主要访花者为蜜蜂与熊蜂，且熊蜂在早秋时节的访花频次显著提升。该植物可作为秋季等食物匮乏期的优质花粉来源。本研究建议将外高加索刺萼参应用于集约化农业区的非耕作农田，以及蜂箱周边的野生花卉带种植中。后者方案可助力蜜蜂为蜂群采集花粉与花蜜，进而保障蜂群具备足够活力以顺利越冬。