Published in Scientific Papers. Series B, Horticulture, Vol. LXV, Issue 2
Written by Nora Eugenia D. G. ANGHELESCU, Hajnalka KERTÉSZ, Hajnal PATAKI, Mihaela I. GEORGESCU, Sorina A. PETRA, Florin TOMA
Pollination by sexual deception is thought to be the most remarkable mechanism of pollination, mainly characteristic to Orchidaceae, which has independently evolved throughout Europe, Australia, Asia, South Africa and Central- and South-America. Sexual deceptive mimicry is a complex deceptive mechanism in which the orchid flowers went through remarkable evolutionary morphological changes in their structure and function, especially that of the labellum, in order to achieve visual (shape and colour), tactile (texture and pilosity) and olfactory (sex-hormones or pheromones) mimicry of the signals used by various insect female species in breeding condition. Because insect mating signals are usually very specific, pollinator attraction by sexual deception is also very specific, each orchid only attracting one or two insect species. In Romania, Ophrys genus is represented by four species only: Ophrys insectifera, Ophrys sphegodes and Ophrys oestrifera (all cross-pollinated by insects) and Ophrys apifera (self-pollinated). This article describes and illustrates for the first time in Romania, the phenomenon of pollination by pseudocopulation of Ophrys insectifera and its unique pollinator, the solitary male wasp Argogorytes mystaceus, and Ophrys oestrifera and its male bee pollinator Eucera longicornis. In the same time, it is described in detail the self-pollination mechanism employed by Ophrys apifera. Using advanced techniques of ultra-macro photography, details of floral organs are illustrated in order to show the spectacular morphological modifications of the bee-like flower labellum.
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