LEADING THE FIGHT: Rainbow Honey manager Rae Butler, left and Nelson Honey and Marketing managing director Philip Cropp will be breeding bees that will be more tolerant of varroa.

A Motupiko company has taken up the challenge of trying to keep alive a programme to breed bees that can tolerate varroa, the blood-sucking mite that has devastated hives all around the world and which costs the New Zealand commercial beekeeping industry millions of dollars every year to control.

For the last eight years Plant and Food scientists in conjunction with the National Beekeepers Association has been trying to breed a self-sustaining population of bees with a natural propensity for cleaning their hives of enough varroa to remain productive and thus reduce the reliance on chemicals which the mites are becoming increasingly resistant to.

Through a rigorous breeding and selection programme based on artificial insemination, colonies of bees with the varroa sensitive hygiene (VSH) behavioural trait were bred, initially at the Ruakura research centre near Hamilton and then on Great Mercury Island. These bees were found to be genetically geared to uncapping a brood and removing larvae infested with varroa.

However, with funding for the $2 million project having run out and few beekeepers with either the resources or technical ability to take it over, the programme was in danger of folding before any attempt could be made to see if it would work commercially.

Unwilling to see the research or the VSH bees go to waste, Nelson Honey and Marketing owner Philip Cropp and the manager of his beekeeping company, Rae Butler, have agreed to pick up the breeding work in the hope they can convince enough beekeepers it is a viable option in the fight against varroa.

"They offered it to all beekeepers around New Zealand and there was only a couple who looked at it because it is quite a daunting project as it needs someone with a bit of vision who is willing to give it a go and see if they can move it to the next stage," Mr Cropp says.

"Rae has always wanted to get into this side of breeding and she's really excited about it and I always like a challenge and trying different things, and if we can pull it off it is going to save millions because beekeepers won't have to buy so many treatments."

Currently beekeepers typically spend between $40 to $50 a year treating each hive, estimated to total $20 million and about a fifth of their costs. Most use synthetic chemicals twice a year, although those also using organics have to treat more often as they don't give as good a kill rate.

However, many of the harder chemicals used are becoming less effective as varroa develops resistance. Already a major problem overseas, resistance has started to spread from the top of the North Island and scientists believe it is only a matter of time before colonies throughout the country are largely defenceless to the mite which has virtually wiped all wild hives and is now found in almost all managed hives bar some in the deep south.

Mr Cropp says VSH bees are not a "silver bullet" but have the potential to reduce varroa by 60 to 70 per cent, enough to keep it under control and hives still producing honey.

"If we can get bees even 60 per cent tolerant we will never lose our hives. We might get varroa building up but it will require perhaps one treatment a year and that is going to save beekeepers thousands of dollars each."

But the Nelson company has significant hurdles to overcome to get the venture off ground, let alone make any money from it.

Conducting an artificial breeding programme is costly and time consuming. For example, it takes four hours using a microscope counting mites and looking at bee broods just to check whether a hive has the VSH trait, and weeks to breed a hive using a queen with the gene.

It also requires a high degree of technical skill, something that Ms Butler is about to get a crash course in.

This week they took virgin queens bred from three different lines of VSH bees up to Ruakura to be artificially inseminated with semen collected from drones with the trait. They hope to return with 30 to 40 queens from which they can graft eggs to boost their stocks, while Plant and Food scientists breed from two other lines. Nelson Honey and Marketing subsidiary Rainbow Honey will pay a royalty for each inseminated queen but hopes to recoup the cost by selling five lines of bees to other beekeepers.

Ms Butler will then head to the United States in March to be trained in artificial insemination and spend time with a beekeeper there who is also learning the technique before returning to set up a similar service at Rainbow Honey's Motupiko base. She will also test other beekeepers' hives for VSH.

She says that while the main priority is to keep VSH bee populations alive so scientists have more time to study them and develop a quicker DNA test, they also want to get other beekeepers involved in spreading the trait.

"We don't want to get to the stage where we are relying on one or two lines of bees."

National Beekeepers Association Nelson president Frazer Wilson says it's a great idea, but not everyone is convinced it will work, with some breeders saying the VSH trait will be diluted through queens free mating with drones without the gene.

Mapua queen breeder Matt Davidson says he can't see how the programme will work unless it relies completely on artificial insemination which will ultimately reduce bloodlines and lead to inbreeding problems.

"I'm not adverse to any new research or programme that can combat varroa – it's admirable that people are trying – but I'm very sceptical of its success."

Frans Laas, a former NBA president who runs an artificial breeding programme for Dunedin-based Betta Bees, says they are technologically difficult and expensive to run.

His company is running an alternative programme based on whole gene selection rather than a single trait which he says is starting to show some promise.

"Some of our bees only need to be treated once a year (for varroa) but the difficulty is getting that genetic advantage into a whole population and maintaining it.

"It can only be done through a closed breeding population because bees tend to free mate and a queen can roam 5 to 10 kilometres away and she will mate with any drone who happens to be in the district and you have no idea how good they are and where they belong."

But Ms Butler says even though cross breeding does dilute the gene, it is still useful because it is spreading it more widely through the bee population.

Having more than one breeding programme will also help preserve different VSH lines.

She says the response from commercial beekeepers to the Nelson initiative has been very positive, particularly from those using more expensive organic treatments.

Plant and Food scientist Michelle Taylor, who oversaw the Great Mercury Island project, says Mr Cropp and Ms Butler deserve praise for being willing to continue the VSH programme when no-one else was.

With chemical resistance spreading throughout the country, there is little else with the same potential to control varroa, she says.

It is vital such work continued otherwise "we might end up with no bees as resistance grows", she says.

"We are getting into a precarious position where our bees are not healthy enough."

Her colleague, award-winning scientist Mark Goodwin, says varroa is the No1 threat to bees because it not only feeds on their brood but spreads viruses to adult bees.

He has been conducting trials on a fungus which can kill up 90 per cent of varroa over time and is not harmful to bees but it requires more testing and is still some way from gaining approval from the authorities.

Under siege from a host of threats, bee populations overseas are in decline, with losses of up to 30 per cent a year recorded in the US and Israel. "We are probably at 5 per cent, but once we get chemical resistance we expect that to increase significantly."