"sexual deception... the case for the endangered Frankston spider orchid [Caladenia robinsonii G.W.Carr], which lures male wasps to mate with the flower they think is a female wasp.
Botanists had a significant breakthrough last week when they managed to dupe some male wasps into pollinating the orchid flowers during a trial at the Royal Botanic Gardens at Cranbourne. The last remaining wild population of the orchid is down to about 20 plants at a secret location on the Mornington Peninsula. The species' future was grim, with no new plants emerging in recent years. Chances of pollination are also further reduced because wasps will often remember the location of an unsuccessful mating attempt and will not be fooled twice by returning to the same plant. The species was discovered in 1985 at Frankston on a site later cleared for housing. It was believed to be extinct before the Mornington population was discovered in 1990. The National Herbarium in Melbourne has successfully grown about 100 Frankston spider orchids and last week some were taken in tubes to the Royal Botanic Gardens in Cranbourne to see if they could attract pollinators at the site. The flowering orchids release a pheromone that attracts the male thynnid wasp, which then tries to mate with the labellum of the orchid.. "We were thrilled as it was windy so it was quite remarkable the wasps were able to follow any trail at all," said Department of Sustainability and Environment biodiversity officer Karen Lester. "It was a hypothesis that the pollinator was a wasp, but we didn't know as we didn't believe we had any natural pollinators left at the wild site as no pollination has occurred," she said. The wasps were captured and will be formally identified in the hope they can help pollinate and restore the surviving wild orchids at the Mornington site. DSE hopes to use the plants at the herbarium to plant two new sub-populations at the Mornington Peninsula site and at the Cranbourne gardens next year. A fungus that lives in the roots of the orchid and germinates the seeds has also been collected and grown to help bring the rare orchid back from the brink. The Frankston spider orchid is one of 60 orchid species under threat in Victoria." URL : http://www.theage.com.au/news/national/male-wasp-duped-in-orchid-mating-game/2007/10/23/1192941066179.html ************** Regards, VB _______________________________________________ the OrchidGuide Digest (OGD) [email protected] http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
