The Verroa destructor mite has decimated bees overseas leaving Australia as the only continent without the invasive species. But what would happen if bees were to suddenly decline in Tasmania - at a time when crop production is expected to surge?

With this in mind, a researcher at the University of Tasmania set about investigating a potential back-up pollination source: native insects.

PhD student in environmental studies Adelina Latinovic looked at which native plants in the Midlands attracted which native insects, and whether these native insects were interested in her chosen crop of study, carrots.

She then analysed when these native plants flower, if this flowering would interfere with the crops, or if they could be co-ordinated to flow into each other and allow insects to transition across.

"If we could target our revegetation efforts to have the right plants in the right places, that could really benefit agriculture by having native insects assist in pollination," Ms Latinovic said.

"I looked at a list of native plants that grow in the Midlands that we know honeybees like, but where there was not much research about native insects that go to them.

"When do these plants flower? Can we have something like the eucalyptus flower before the carrot crops, and for the native plant to retain the insects in the area to act as a back-up?"

Insects on crops is often a source of frustration for farmers, but Ms Latinovic said native bees, beetles and flies were all pollinators that could play a part alongside rented honeybees, or if rented bees were unavailable.

"With beetles and flies, they feed more on the pollen and nectar. Their purpose isn't always to pollinate. But they do transfer pollen while they're there," she said.

"Hover flies and drone flies are good at pollinating.

"They're not all equally efficient, but there was a study coordinated by the University of New England that found native bees were more efficient but made fewer visits, while flies and beetles were less efficient but made more visits to the crops."

To find out what was going on, Ms Latinovic carried out a series of 10-minute observations over a one-metre-square area on a native tree or plant in areas from Richmond to Cressy, finding out what insects were coming, going and staying.

She also kept a close eye on the carrot crops.

"A third of the insects we saw on the carrot crops were bees - half of those were native, and half of those were bees that were rented for pollination," Ms Latinovic said.

"Another third were beetles, and another third were flies. It was a three-way split, really."

A calendar is being developed to show which native plants flower when to aid in attracting native insects at the right time just before pollination is needed on crops.

It is particularly important for crops that overlap with the leatherwood season when the available reserve of rented bees is greatly reduced.

The final results of Ms Latinovic's studies will be determined in 2020.

She hopes her work can aid in native revegetation works being carried out across farms in the Midlands, adding to a growing pool of research guiding targeting development of native woodland.

In addition to carrots, native insects could also be effective pollinators for brassicas such as canola and kale, and fruit orchards like cherries. Earlier Tasmanian studies even showed a 30 per cent increase in poppy production with native insects.

"There is a relationship and my findings have been positive so far," Ms Latinovic said.

The Midlands will be among the next areas of Tasmania to see significant irrigation upgrades in the coming years as the government targets a massive increase in agricultural production.

More crops need more pollination.

And like with any species, collapse in bee numbers can be sudden and unexpected.

"I couldn't say if bees are declining in Tasmania, but that's part of the importance of what I was doing. I wanted to know what was out there so we can have some back-up strategies so we can figure out how to manage it if a disaster happens with bees," Ms Latinovic said.

"If the Varroa destructor - a parasitic mite that attacks honeybees at all stages of their life cycle - comes to Australia, that would be a huge problem. It also increases the costs associated with keeping honeybees.

"In Tasmania, we don't really have enough bees to pollinate carrot crops because it overlaps with the leatherwood season and it's not fair to draw beekeepers away from that."