The tropical fruit, which tastes similar to a lychee, is harvested during northern Australia's wet season and enjoys strong demand from consumers during Christmas and Chinese New Year.

However, the trees often fail to turn flowers into fruit, much to the frustration of growers.

NT Department of Primary Industry research entomologist Mary Finlay-Doney said this was the main reason growers were keen to get involved in the study.

"We're trying to investigate whether using managed pollinators in those orchards will help get greater fruit set and greater yield," Dr Finlay-Doney said.

Grower Kerry Eupene welcomed the study, and said a little bit of research could go a long way for the rambutan industry.

The Tetragonula mellipes stingless bees being used in the study are part of an apiary the department has built using hives rescued from the Berrimah Research Farm.

"Berrimah Farm is being developed into a residential subdivision and a lot of our buildings are being knocked down," Dr Finlay-Doney said.

According to Dr Finlay-Doney, the apiary, made up of almost 30 hives, is the only Tetragonula mellipes apiary in Australia.

She said it was not unusual for stingless bee apiaries to be built on rescued hives, but the hives rarely came from buildings.

"In south-east Queensland a lot of that rescuing is out of trees that are being knocked down for suburban developments."

Dr Eupene said he had long noticed that stingless bees were busy pollinators in the orchard.

"We've been interested to know what they're actually doing in there, because no-one seems to know," he said.

Dr Finlay-Doney said as well as being hard workers, the stingless bees were also ideal for the job because they did not mind flying under nets.

"Most rambutans are grown under nets, and so for pollination services you need insects that are able to fly under netting."

Dr Eupene agreed that honey bees were not ideal for pollinating rambutans.

"The rambutan flower is pretty small and the European honeybee is a bit clumsy to get in there, whereas the native [stingless] bee fits very well inside the flower, so they're a better option," he said.

The other reason the stingless bees are ideal, according to Dr Finlay-Doney, is because they are endemic to Darwin.

While the study has rambutan growers excited, Dr Finlay-Doney said it had also drawn interest from other growers.

"There is interest from berry producers and from other tropical fruit crops," she said.

"[But] for us this is a very local, specific question because we're dealing with an endemic species."

As the study is in its first year, it will be a while before there are any definite results.

"At the moment what we're doing is very fundamental counts in orchards looking at bee visitation on flowers and looking at receptiveness of flowers to pollinations," Dr Finlay-Doney said.

"We're probably looking at another two to three years before we can demonstrate their [the bees'] effectiveness in orchards."