Mimesis of bellflower (Campanula) by the red helleborine orchid Cephalanthera rubra

• Published in: Nature (London) Vol. 305; no. 5937; pp. 799 - 800
• Main Author: Nilsson, L.A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 01-01-1983
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Biological and medical sciences; Campanula; Fundamental and applied biological sciences. Psychology; General aspects; Megachilidae; pollution; Monocotyledones; Insect pollination; Insecta; Megachilidae; Pollination; Floral biology; Orchidaceae; Arthropoda; Dicotyledones; Angiospermae; Campanulaceae; Spermatophyta; Invertebrata; Hymenoptera
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/305799a0

The spectacular red helleborine orchid (Cephalanthera rubra ) is distributed from Iran throughout the Mediterranean region and up to western Europe, reaching southern Scandinavia. The plant preferably grows on calcareous soils in dry woods. The elongate, loose inflorescence usually bears 4-10 brilliantly rose-coloured flowers which completely lack nectar or other food for anthophilous insects and thus act by deceit. Flower-visitors so far reported are bees, especially males of the solitary bees Chelostoma fuliginosum (Pz.) and Chelostoma campanularum (K.) (Megachilidae). Females of the two exclusively from bellflowers (Campanula ). Mate-seeking flights, feeding and resting of the males are strongly associated with Campanula flowers. The authors reports that C. rubra mimics the floral coloration of Campanula in the bee visual system and thereby receives pollination service by the Chelostoma males. Pollination is regularly effected by males of C. fuliginosum . The orchid peaks in anthesis distinctly before Campanula , phenologically matching and efficiently exploiting the male bee population.