Australian honey bees are some of the most healthy in the world. If they’re allowed the time, they will develop varroa resistance on their own. Other populations have- ours can too.
Aug. 7, 2015
Some honeybee colonies adapt in wake of deadly mites
A new genetics study of wild honeybees offers clues to how a population has adapted to a mite that has devastated bee colonies worldwide. The findings may aid beekeepers and bee breeders to prevent future honeybee declines.
The researchers genetically analyzed museum samples collected from wild honeybee colonies in 1977 and 2010; the bees came from Cornell University’s Arnot Forest. In comparing genomes from the two time periods, the results – published Aug. 6 in Nature Communications – show clear evidence that the wild honeybee colonies experienced a genetic bottleneck – a loss of genetic diversity – when the Varroa destructor mites killed most of the honeybee colonies. But some colonies survived, allowing the population to rebound.
“The study is a unique and powerful contribution to understanding how honeybees have been impacted by the introduction of Varroa destructor, and how, if left alone, they can evolve resistance to this deadly parasite,” said Thomas Seeley, the Horace White Professor in Biology at Cornell and the paper’s senior author. Sasha Mikheyev ’00, an assistant professor of ecology and evolution at Okinawa Institute of Science and Technology (OIST) in Japan, is the paper’s first author.
“The paper is also a clear demonstration of the importance of museum collections, in this case the Cornell University Insect Collection, and the importance of wild places, such as Cornell’s Arnot Forest,” Seeley added.
In the 1970s, Seeley surveyed the population of wild colonies of honeybees (Apis mellifera) in Arnot Forest, and found 2.5 colonies per square mile. By the early 1990s, V. destructor mites had spread across the U.S. to New York state and were devastating bee colonies. The mites infest nursery cells in honeybee nests and feed on developing bees while also transferring virulent viruses.
A 2002 survey of Arnot Forest by Seeley revealed the same abundance of bee colonies as in the late 1970s, suggesting that either new colonies from beekeepers’ hives had repopulated the area, or that the existing population had undergone strong natural selection and came out with good resistance.
By 2010, advances in DNA technology, used previously to stitch together fragmented DNA from Neanderthal samples, gave Mikheyev, Seeley and colleagues the tools for whole-genome sequencing and comparing museum and modern specimens.
The results revealed a huge loss in diversity of mitochondrial genes, which are passed from one generation to the next only through the female lineage. This shows that the wild population of honeybees experienced a genetic bottleneck. Such bottlenecks arise when few individuals reproduce, reducing the gene pool. “Maybe only four or five queens survived and repopulated the forest,” Seeley said.
At the same time, the surviving bees show high genetic diversity in their nuclear genes, passed on by dying colonies that still managed to produce male bees. The nuclear DNA showed widespread genetic changes, a signature of adaptation. “Even when a colony is not doing well, it can still produce a batch of males, so nuclear genes were not lost,” Seeley said.
The data also show a lack of genes coming from outside populations, such as beekeepers’ bees.
The surviving bees evolved to be smaller, suggesting these bees might require less time to develop. Since the mites infest nursery cells in hives, the shorter development time may allow young bees to develop into adulthood before the mites can finish their development. Mite-resistant honeybees in Africa are also small and have short development times, Seeley said.
Next, the researchers will study which genes and traits confer resistance to Varroa mites. The findings may help beekeepers to avoid pesticides for controlling mites and to trust the process of natural selection, and bee breeders to develop bees with the traits that have enabled bees to survive in the wild.
The study was funded by the OIST and the North American Pollinator Protection Campaign.
From 30th June to 7th August the TECA Beekeeping Exchange Group will host a moderated discussion on bee diseases and the use of veterinary medicines in beekeeping around the world. The discussion is held in collaboration with the Regional Institute for Animal Diseases of Latium and Tuscany (IZSLT – Italy) and APIMONDIA. Beekeepers are invited to participate in the survey (English, French, Spanish and Italian) that will allow monitoring beekeepers’ knowledge and learning about beekeepers’ challenges related with bee diseases and health.
Find all the useful documents related to the discussion HERE.
Moreover, APIMONDIA with the assistance of the TECA Beekeeping Exchange Group (TECA stands for Technologies and practices for smallholder farmers), IZSLT and is under the supervision of Food and Agriculture Organization (FAO), organized a Survey on the same matter.
The survey is divided into 3 parts:
Part A: Gather information from participants on their perception of the honey bee diseases and the proper management of the hives.
Part B: Understand the concerns of participants about the main diseases affecting beekeeping in different areas around the world: Varroa, American Foulbrood (AFB) and European Foulbrood (EFB).
Part C: Understand what kind of assistance beekeepers receive to face the honey bee issues.
The survey is completely anonymous (you do not have to give your name) and will only take about 10-15 minutes to fill in.
You can find the Survey at: https://es.surveymonkey.com/r/Veterinary_medicines_in_beekeeping2015
Although chalk brood has a global distribution, little is
known about Australian strains of A. apis and its virulence toward honey bees. We are working to rectify that! Here are some pictures of culturing A. apis from chalk brood mummies last month.
Ascosphaera apis is the fungus that causes chalkbrood disease in honey bees. The spores of this fungus are extremely hardy and can stick around in honey, wax, pollen, bee bread and the hive architecture for up to 15 years! Bee larvae are fed the spores at about 3rd instar and if the conditions are right in the larval gut, the spores dormant and begin to grow hyphae. These hyphae puncture the larval gut lining and eventually the larval cuticle. The hyphae then grow all over the outside of the larva causing death about 3-5 days later during the 5th install- just as the larva is being capped over,
elongating in the sell and preparing to pupate.
If a larva succumbs to chalk brood infection the dead body will dry up and become a chalk-like white mummy in the brood cell. This type of fungus needs two mating types to reproduce. When hyphae of opposite mating types come onto contact, ascocarps are formed which is essentially a big spore cyst that contains smaller balls that contain spores. These ascocarps turn the mummy black and when they rupture distribute spores through the colony further spreading disease.
An upcoming survey of the Australian honey bee industry will collect baseline data that will provide information on the current economic situation of Australian beekeepers.
Minister for Agriculture, Barnaby Joyce, said the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) survey would provide a thorough picture of changes to the national industry along with an up-to-date profile of the physical and financial characteristics of honey bee businesses.
“In addition to data on the demographic and socioeconomic circumstances of people in the industry, the survey will capture the adoption of research and development initiatives, the state of honey bee health and the size of the commercial pollination services sector,” Minister Joyce said.
Minister Joyce said the value of Australia’s bee industry extended far beyond the quality products produced to the valuable pollination services of honey bees.
“More than 12,000 registered beekeepers are tending to more than 520,000 hives across the country that produce about $90 million worth of honey and beeswax each year,” Minister Joyce said.
“Bees are important not just because of the honey they produce. About 65 per cent of Australian agricultural crops respond to honey bee pollination. Among others, Australia’s $346 million almond crop depends entirely on bees for pollination.
These are some scanning electron micrographs we I took of bee collected pollen. The first three pictures are from a load of “yellow” pollen from some Eucalyptus species and last three are from a load of “orange” pollen of uncertain origin. The next step is to collect pollen directly from plants to make a reference collection. We can then compare the bee collect pollen against the reference collection to get a more solid idea of what the bees are actually foraging on!
Tasmanian Beekeepers Annual Conference will be held at Tall Timbers Hotel, Smithton on the 29/30th May, 2015
Guest speakers include –
Dr Peter Brooks and Daniel Melconceilli, University of Sunshine Coast – A few pointers on producing active Tasmanian Manuka Honey and Authenticating the floral sources of Tasmanian Honey through chemical profilint, and their anit-flammatory activity.
Mr John Rawcliffe, NZ – UMF Honey Association’s Manuka ID Project
Ms Jody Gerdts – Hygienic Behaviour of Bees
Mr Ben Hooper – Beekeeping in SA & Nuffield Scholarship Report
Mr Sam Malfroy , Plant Health Australia – National Biosecurity Plan
ALL WELCOME – REGISTRATIONS AVAILABLE – EMAIL SECRETARY – firstname.lastname@example.org
Autumn has finally come in full force and with it cooler mornings that have enabled us to test out our new infrared (heat sensing) camera!
Here are some pictures of a few colonies in nesting cavities and in bee boxes . Ambient temperature this morning was 7-8 C.
This is a tree on the La Trobe University Bendigo campus that has a feral honey bee colony in a bird or bat nesting box. The whitest part of the picture is the nesting box. It is surprising how much heat trees generate!
The next three pictures are of another feral nest on the way to Maldon, Victoria from Bendigo. You can see the heat from the tires of my ute and in the foreground the orangish pink indicating some heat from the tree. The next picture is a close up of the tree hollow.
Finally, some pictures of bees in boxes. You can see the yellow patch of the cluster in the bottom box of each of the double colonies and see some heat in the mid section of the nucs. Each of the doubles has a solid 8 frames of bees and the nuc boxes have 5 frames of bees.