Credit: Rod Peakall

Orchids have adapted the shape of their flowers to attract pollinating wasps.

These flowering plants lure male insect pollinators by producing chemicals that mimic the pheromones of their female counterparts, but the effect of flower shape on pollinators has been unclear. To look at this, Marinus de Jager and Rod Peakall at the Australian National University in Canberra studied two species of Chiloglottis orchids that emit the same pheromone and the two species of Neozeleboria wasps that pollinate the flowers. They found that the wasps copulated more frequently and for longer periods of time (pictured) with the orchid that they normally pollinate.

The dimensions and colour of the preferred orchid's callus (the central part of the flower) closely resembled the respective female wasp, and the overall shape of the flower allowed the male wasp to fit better within it.

Funct. Ecol. http://doi.org/7rd (2015)