The Australasian Beekeeper

Held at University Of Western Sydney on 12th December 2009, the Bee Genetics Seminar was attended by approximately 100 beekeepers and academics. The Bee Genetics Seminar was sandwiched between the Sue Cobey Instrumental Insemination Courses (Beginner and Advanced) run by the NSW Apiarists’ Association and organised by Doug Somerville. The program for the Seminar was a joint effort between Max Whitten and Doug Somerville. Max was ambushed during the day by Doug, who announced that Max had become the latest recipient of the Goodacre Award, the beekeeping industry’s highest award for services performed for and on behalf of the industry (see separate article).

Prof. Ben Oldroyd: General Problems in Bee Breeding

Ben spoke on the topics of

·         How bees differ – from other ‘animals’ in relation to breeding

·         Molecular tools that can assist the breeding of honeybees

·         Design of bee breeding programs

·         Future molecular tools that may become of assistance.

Ben then went on to identify the 4 main difficulties of bee breeding – the identification of superior individuals, the control of the mating process, problems caused by in-breeding, and the difficulties of obtaining/providing adequate funding for bee breeding programs.

Topics also introduced were the problems raised by poor drone parentage, and the interactions between phenotype and genotype, plus the effect of the environment on the expression of those characters; the different methods of controlling the mating process (AI, Isolated mating, manipulated mating); and the potential for use of microsatellite genetics to identify such things as pedigree, inbreeding and genetic variation, population genetics, the density of feral bees, and the mapping of important genes.

Finally Ben touched on the things that it would be possible for molecular genetics to test (simple traits such as colour, hygienic behaviour) and the things that would be out of reach (complex situations such as honey production); and the use of molecular DNA to trace the parental origins of honeybees (indicating, for example, that ligurian bees on Kangaroo Island possibly originated from southern France rather than Italy)

Peter Oxley: Genetics of Hygienic Behaviour

Peter Oxley

Peter discussed the concept that bees are affected by both pathogens and parasites, and in response to these have developed both genetic resistance and behavioural resistance. The latter is what we commonly call  ‘hygienic behaviour’, and has three components:

1.       The detection of the problem – dead or diseased larvae

2.       The uncapping of the diseased larvae

3.       The removal of the diseased larvae

Peter went on to explain that all bees are hygienic, but vary in how quickly they respond. Hygienic behaviour can be slow or rapid in the nature of the response. Methods for testing of hygienic behaviour include

·         The pin test – which can give a false reading, in that the bees have already been alerted to the presence of the dead larvae (killed by the pin) and the cap is already pierced

·         Freeze-killed brood (either in the freezer of by liquid nitrogen

·         Genetic testing. This has shown that there are a number of gene loci related to hygienic behaviour, and that bees possessing 3 or more loci will be rapid in response, while bees with 2 or less will be slow in response.

From the millions of gene sequences identified, the field has been narrowed down to 5 genes which appear to be strongly related to detection and uncapping.

Dr Andy Barron: Honeybee Population Genetics – Why Do Colonies Collapse

Andy explained that his team have developed a model for the collapse of honeybee colonies and are now looking to test that model in the field, with a view to obtaining feedback on the usefulness of the model.

Colony collapse is observed when there is a rapid depopulation of the adult workforce of a colony, with few workers left to look after the queen and the large brood population left behind.  It is not a new phenomenon – historically there were colony collapse events

1905 Isle of Wight Disease

1906 Victoria - 59% losses – due to fermentation of honey in the hive

1975 Disappearing Disorder hit 27 States in the USA

1995 USA

1998 USA

2006/07 USA 45% losses

2007/08 USA 41% losses

While not new, Colony Collapse ‘Events’ seem to be increasing in both occurrence and severity. The causes are multiple in nature:

·         Influence of Varroa in lowering the immune status of the hive, or in killing the hive outright

·         Nosema apis

·         Viruses having a greater effect because of the influence of Nosema and Varroa

·         Pesticides – particularly the newer ones which target the insect nervous system (eg Imidicloprid – the effects are sub-lethal but cause weakness in the bees

·         Nosema ceranae

·         Israeli Acute Paralysis Virus (IAPV) – both IAPV and Nosema ceranae pre-date CCD in the USA

·         Modern queen bee breeding – which has introduced inbreeding

·         In-hive use of miticides for Varroa control

·         Modern pollination practice – use of large monocultures with associated lack of biodiversity

·         Climate Change- increasing unpredictability of Spring, and an associated lack of nutrient supply during the colony’s growth phase

All of these factors have caused population stress. Andy then discussed the response of bee colonies to these stressors. In a normal hive, the young bees look after the hive (and the queen and brood) and the older bees forage. The normal occurrence is that after 20 days or so, the young bees ‘graduate’ to foraging. The old bees regulate this process by producing Ethyl oleate and passing it to the younger bees. This prevents them from foraging.

A 10% death rate among old bees will lead to the establishment of a stable ratio of young/old bees and a fixed, stable population size within the colony.

A 30% death rate will lead to young bees foraging at an earlier age, and a resultant decline in the population size, leading ultimately to the death of the colony.

Factors to be looked at in the future by Andy and his team include:

·         Considering the influence of disease

·         Whether young bees exert any influence inhibiting other bees in the colony

·         The effect of the loss of young bees (as they change to foraging bees) upon the colony’s ability to raise the brood

Dr Sue Cobey: Breeding Varroa Resistance in Bees

Sue brought to the seminar’s attention the fact that routine use of chemicals will result in the Varroa mites developing resistance, and might also propagate susceptibility in the bees. This is because no emphasis is being placed on propagating honeybee stock that is resistant to the mites. In reference to CCD, Sue also pointed out that there have been at least 61 variables implicated in CCD, and that CCD is best avoided by minimising stress, coupled with good nutrition and reduction in the use of chemicals.

In regards to the breeding of Varroa-resistant bees, resistance is conferred by:

·         Genetics

·         Behaviour

·         Physiological factors

·         Environmental factors

·         Resources and nutrition

·         Colony management

·         Minimisation of stress

Varroa tolerance implies a less-virulent form of the mite, and also implies resistance to the viruses associated with Varroa. The Varroa induces changes in the expression of genes in the honeybee (eg olfactory changes – the bees’ sense of smell changes). Bees have very few genes for immunity and for detoxification of chemicals – this explains why they are susceptible to the added viral load induced by Varroa, and also why they are susceptible to pesticides. Their mechanisms for defence involve hygienic behaviour (grooming, in the case of Varroa) and the use of propolis. Varroa-sensitive hygienic can also involve sensitivity to the Varroa brood volatiles.

To minimise the impact of Varroa, Sue advocates:

·         Use of screen bottom boards

·         Breed for Varroa resistance

·         Good nutrition

·         Minimise other stressors

·         Regular re-queening. This also helps break the brood cycle, making it harder for the Varroa to reproduce.

Good Integrated Pest management (IPM) means one has to

1. Monitor and manage pest levels

2.  Minimise stress 

3.  Use a variety of controls

4.  Utilise selective breeding 

Dr Michael Hornitzky: Role of Quarantine Facilities in Honeybee Breeding Programmes

Michael outlined the historical reasons for the establishment of the Eastern Creek Bee Quarantine facility, which was established to prevent the entry of Varroa, Tropilaelaps, Tracheal mites and Africanised bees. He then explained the import protocols and how they minimised the risk of entry of these internal/external parasites.

Michael then went on to explain that, as the result of the occurrence of CCD in the USA in 2007, a knee-jerk reaction by the Commonwealth Government resulted in a complete ban on the importation of queen bees. This was instigated with no consultation with industry, or with bee scientists or State Departments of Agriculture.

It also means that Biosecurity Australia, in order to allow for future importations, has to carry out a full risk assessment and review of the protocols, formulate a Draft protocol and submit it to industry for comment.  In September, 2009, a two-step process was been put in place:

1.       Future needs will be assessed – looking at industry needs over the next 20-30 years

2.    A new facility will be planned (as a result of the imminent [2015] closure of Eastern Creek)

Max Whitten: The Role of the Wheen Foundation

Max outlined the stated aims of the Wheen Foundation

·         To support research and training for the honey production and pollination services

·         To act as a support centre for bee breeding and stock improvement

·         To assist in evaluation of selected honeybee stock

·         To supply bees for R&D and training

·         To provide facilities for training (AI, disease training,)

·         To possibly act as a national diagnostic laboratory

·         To play a role in lobbying and to support Pollination Australia and honeybee industry bodies.

Max also pointed out that the Wheen Foundation itself will not carry out research, although it will attract tax deductibility for donations for R&D, and that it does not intend to compete with queen breeders – rather it aims to act as a link between industry and researchers, while remaining at arm’s length from both.

Louise Markus MP, Member for Greenway, thanked Gretchen Wheen for her generosity in bequeathing the Wheen Foundation, and gave the audience an outline of Gretchen’s life.

Alby Schultz MP, Member for Burrinjuck, echoed industry’s disappointment with the Government’s (poor) response to the ‘More Than Honey’ Report. Alby stated the blame lay firmly at the Commonwealth Minister for Agriculture’s door for not taking the time to read and digest the Report, and for his failure to act upon it. He labelled the response of both Federal parties as ‘pathetic’. In closing, he warmly applauded the efforts of Gretchen in setting up the Wheen Foundation, and formally declared the Foundation ‘open for business’.

Dr Sue Cobey: Bee Breeding Programs Throughout The World

Sue made the initial points that

·         intra-colony diversity increases genetic fitness, and

·         multiple-mated queens in newly-founded colonies are better able to survive.

Sue then went on to explain that, since in the mating process 90% of sperm are discarded, the quality of the insemination of the queen affects her performance. The mating quality changes the queen bee’s physiology, pheromones profiles and social interactions. A queen that is multiple-mated (as opposed to one which has only mated with one drone) will have a larger retinue of workers around her, and the genetic diversity of the hive assists in hive thermoregulation (control of the temperature inside the hive.

A diverse workforce also

·         communicates more efficiently

·         has a better division of labour in the hive

·         collects more pollen

.     is better able to reduce the prevalence and severity of disease

     

In summary, Genetic Diversity provides the raw tools for selection programs, although funding of stock selection and stock maintenance programs is a major issue. Transmission of viruses is also a risk factor in the importation of both honeybees and drone semen. Successful stock improvement requires

v  controlled mating

v  effective selection methods – simple, effective, repeatable

v  good system design (to reduce inbreeding

v  recognition that, in future, mating the best with the best will NOT be enough to give the most effective program of stock improvement. Genetic factors will have to be considered.

Dr Alexandre Christino: Genomics and Environmental Response in the Honeybee

Alexandre outlined the fact honeybees have been found to have about 10,000 genes puts them at the lower end of the insect scale. This has left them with less genes for immunity and detoxification, and more genes for olfactory (smell) receptors. This leaves bees especially susceptible to pesticides, and future solutions will be to

·         use pesticide-free crops (which may be a practical impossibility)

·         utilise more careful management of pesticides

·         develop pesticides that bees can metabolise\use management to reduce the exposure (risk) of bees. This might be achieved by training the bees to use their sense of smell, to develop a Social Immune System. There about 160 genes for odour reception in the honeybee. It remains to identify which of these are important in identifying disease.

It has been found that Phenethyl acetate (the odour of Chalkbrood) stimulates hygienic behaviour in honeybees

Des Cannon: Importance of Breeding Programs to the Honeybee Industry

Des spoke briefly to the seminar on the need to avoid the problems encountered overseas in the use of chemicals to control Varroa, and of the work being done in Europe and the USA to breed European honeybees that can co-exist with Varroa. He re-iterated that the contamination of beeswax from overuse of miticides has resulted in a detrimental effect on viability of drone sperm, and also on the development of the queen.

In summation he advocated that, if Varroa arrives in Australia, we need to limit the use of chemicals to as short a time-frame as possible, and utilise breeding for Varroa resistance/tolerance to the maximum benefit. Some of these points had been previously made by Sue Cobey, and were supported later by Danny Weaver, who outlined the work done by Weaver Apiaries in Texas, to successfully follow the breeding path rather than the chemical path.

Danny Weaver: Breeding of Varroa Resistance in Honeybees

Danny gave a very informative and entertaining talk on his experiences with Varroa, and emphasised that it is possible to breed bees that are resistant/tolerant to Varroa, but that there will be disappointments and heartache along the way. By leaving some stock exposed to varroa, and breeding from the survivors, it is possible to disseminate the resistance.

Danny did, however, try to emphasise that hygienic behaviour for Varroa resistance is NOT the same as hygienic behaviour for disease resistance. The former involves more grooming behaviour; the latter involves detection and removal of diseased larvae.

Linton Briggs: Stock Improvement Programs in Australia

Linton spoke to the historic perspective in the development of breeding programs in Australia.  He discussed the need for industry to identify the best strategic path for the future to follow in the future, especially given the market intolerance for chemical residues, and the need to cope with the impact of Varroa if it arrives in Australia. He also spoke of the possibilities for an integrated bee breeding, research and educational facility.