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Monday, 12 May 2014

The bee orchids: Aggressive Mimicry



Possible the most remarkable form of mimicry in the plant kingdom is that found in the genus Ophrys, the bee orchids. . The flowers of these orchids have evolved to mimic the appearance of a bee or wasp and the plants use three means to fool insects. First, the lower petal, known as the labellum, bears a remarkable resemblance to a bee in size, shape and coloration, Second, the flower does not stop at just using visual signals to attract insects; it also use tactile stimuli, with the presence of hairs on the sides of the labellum. Third, the flower has evolved to produce fragrances that mimic sex specific pheromones for particular species of bee or wasp. Thus, there are a lot of different shapes of flowers to attract different insects.


The flowers attract the insects using visual, tactile and olfactory stimuli. The plant fools the male bees or wasp into believing the flower is a female. The male then try to copulate with the flower which involves the insect brushing against the pollinia of the flower. So, the frustrated insect visits other flowers and the pollen is transferred. 

It is awesome. A lot of scientists are studying how this process started. That evolutionary feature might be a decisive aspect to keep this genus alive. However, this type of mimicry causes some problems. The relationship can become so specific. Then the flower depends on the insect to reproduce. If some problem occurs with the insect the flower may be extinct. 

Look that video which show more details about these wonderful plants! 




Reference
Scott, P. 2008, Physiology and Behaviour of plants, 1st edn, Wiley: USA
Video viewed 11 May 2014:
You tube: https://www.youtube.com/watch?v=-h8I3cqpgnA

3 comments:

  1. That is indeed very awesome! I find it amazing that these plants can mimic not only the visual aspect of the pollinator, but also its chemical signal! Do you know the chemical constituents that make up the pheromone-like signal? Do a number of different species mimic one type of pollinator, or are there lots of different pollinator models? Very interesting!

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  2. Yes, that is awsome! Each orchid species has his specific pollinator, so there lots of different pollinator models. As each species has his own pollinator so ach one release different compounds. For example, spider orchid (Ophrys sphegodes) release C21-29 alkanes and alkenes and Octadecanal, that are prepollination, to attract. Also, they release Trans-farnesy hexanoate as a postpollination to avoid be pollinated twice.

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  3. That's really interesting how the flowers are able to bees and wasps! I found it intriguing that they can specifically mimic females insects in order to get male bees to brush up against them and pollinate them.

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