Mellblom’s Spider-orchid was once common in Victoria and South Australia, but by 2015 there were only 400 scattered plants left in the wild near Portland.

Noushka Reiter, the research scientist leading the orchid conservation program at the Royal Botanic Garden Victoria, said the rare plant would have become extinct within decades if not for an innovative relocation strategy.

Dr Reiter explained that for the strategy to work, the spider-orchids at the Royal Botanic Garden had to be relocated to sites that contain the wasps they rely on for pollination.

“Mellblom’s Spider-orchid has a remarkable pollination strategy,” Dr Reiter said.

“The orchid lures male thynnid wasps by mimicking the sex pheromones of the female wasp. Wasps pick up pollen when they try to mate with the flower and take it to the next orchid where they are tricked again.

“There is no point translocating the orchid to areas that don’t have the wasp – and it isn’t common - so in 2014 we used surveys to identify two remaining orchid areas that still have thynnid wasps.”

Experts worked with volunteers to relocate almost 450 orchids.

Three years on, the project has been a success and was celebrated at a nationwide conference on Tuesday focusing on the conservation and relocation of rare Australian plants.

“It has been a success - we are seeing natural pollination and seed set at both sites,” Dr Reiter said.

“The success is due to many partners including Parks Victoria, Alcoa/ Portland Aluminium, Australian Network for Plant Conservation and enthusiastic community groups.”

Botanic Garden scientist and Australian Network for Plant Conservation committee member Cathy Offord says plant translocation was a relatively new but rapidly growing field, which is used together with more traditional conservation approaches such as bush regeneration and weed management.  

“Plant translocation is the plant equivalent of captive animal breeding and release programs that are increasingly carried out by zoos and animal sanctuaries,” Dr Offord said.