Shropshire Beekeepers' Association

 

 

Newsletter : May 2007

1.      Editor's Notes

Bees and beekeeping seem to have become a hot topic in the media. Several members have drawn attention to the problems being reported from America about ‘Colony Dwindle Disorder’ (CDD) whereby hives seem to have been abandoned without explanation. Similarly, hornets seem to be hitting the headlines - sometimes in a lurid way as in a recent over-the-top dramatised documentary on television. However, “all publicity is good publicity” as the saying goes, and this interest and concern for the welfare of bees makes it more likely that pleas for better support for research and practical help for beekeepers, as penned in the press recently by the BBKA Chairman, Tim Lovett, are more likely to fall on fertile ground. The article from Stratford-on-Avon's Newsletter below demonstrates the value of good research, in this case into varroa and its effects. More of this kind of work is needed and it cannot be done without proper support from the government.

Stuart Foster’s account of his own colony losses this winter (Item 5 below) are similar to those being experienced by many other members. There is no evidence that these failures are connected to the events in America but they are frustrating for those involved. One of the things we can do as an Association is to support fellow beekeepers, so if anyone can offer bees, queens/queen cells or swarms to other members, please make it known. Our Chairman, Ray Green, will act as a clearing house so if you can help but are not sure how to go about it, please get in touch with him. (Contact details on the Committee page.)

On a lighter note, the researcher for Anne Robinson’s show ‘The Weakest Link’ has circulated us to say that they are looking for contestants with unusual hobbies to take part in the next series. Beekeepers apparently qualify! The ‘flyer’ is here. For more information and an application form you can call 0900 10 200 22 or email weakestlink@bbc.co.uk

 

2.      Last Meeting : A Licence for Beekeepers.

John Hendrie, the General Secretary of the Kent Beekeepers Association and long associated with the BBKA Examinations organisation, talked to us about the purpose and benefits of following the syllabus of these exams. He pointed out that we accept the importance of having qualifications to demonstrate competence in so many of the skills demonstrated in everyday life, from driving a car to conducting brain surgery. Further, in these days of legal action for negligence at the drop of a hat, a qualification can be an important piece of evidence to show that we know what we are doing in our beekeeping.

The BBKA Basic Assessment in Beekeeping is the foundation of this examination system and must be achieved before any of the more expert modules are tackled. It focuses on the straightforward competencies and knowledge that we need to have to handle bees successfully. This involves meeting with an assessor at a designated apiary, demonstrating practical skills and answering questions to do with bees and beekeeping. The practical activities include:

The topics to be discussed might include: A full syllabus can be obtained from the BBKA who can also advise on making an entry to take the Basic Assessment.

 

3.      Next Meeting

Our first Apiary Meeting is on Saturday May 12th at 2.30 p.m. at the Association Apiary at Radbrook. As usual for our first meeting there will be a ‘Bring & Buy’ of unwanted or spare equipment, so please bring along anything surplus to you requirements that might be welcome to other members. At the moment the apiary is rather low on bees(!) but there will be helpful demonstrations and discussion on managing varroa and other topical tasks.

 

4.      Varroa Tolerance/Resistance In Apis Mellifera

In the May edition of the Stratford-on-Avon BKA Newsletter, Peter Edwards reported a lecture on varroa tolerance and resistance given by Dr. Stephen Martin of Sheffield University to a recent BIBBA meeting. It summarises the latest knowledge on this vitally important topic. [Copied courtesy BEES]

Viruses
Viruses are important because of the fact that they, rather than the varroa, kill colonies. Viruses can exist in bees without causing disease (this is known as an inapparent infection) because approximately 100,000,000,000,000 virus particles are required to cause disease when applied by ‘normal’ routes (e.g. ingestion). However, if a varroa mite picks up virus from the haemolymph (blood) of an adult bee and then injects it into a larva when feeding, only 100 particles are required to have the same effect. This why varroa is such a problem - it transmits virus from adults to larvae in a way that would not normally happen.

Virus infected bees often die away from the hive - leaving the hive empty, or with just the queen and a few bees - the so-called ‘Marie Celeste’ syndrome. When varroa first arrived in this country these viruses were more rare, so varroa numbers could be very large, perhaps 10,000-20,000 per colony. They did not cause much damage because they were not transmitting virus. Now, after many years of varroa spreading them, viruses are endemic as inapparent infections in adult bees, so if a mite feeds on an adult bee it is now very likely to pick up virus particles which it will then transmit to any larvae on which it feeds - and remember that only 100 particles will cause disease when the particles are injected into the larvae in this way.

There are at least 14 viruses that affect bees - and we do not know what impact they all have, though Acute Paralysis Virus (APV) will cause a colony to collapse very quickly - it kills in days, whereas Deformed Wing Virus (DWV) will cause the colony to decline more slowly. This increase in the amount of virus in our colonies is the main reason why varroa is a much greater problem now than when it first arrived, and the differences in the effect of each virus explains why some colonies collapse in days whilst others go into slow decline. The only solution is to keep numbers of varroa low - certainly well below 2000. You will probably not see varroa if there are only 2000 in a colony. Bees in the tropics and Africanised bees survive because of constant brood rearing providing new bees; in temperate climates where brood rearing is reduced or ceases during the winter months, the dying bees are not replaced and the colony therefore dies out.

Resistant mites
Three possible ways that varroa could have developed resistance:

Recent research suggests that varroa has become resistant by the sodium channel route and that this probably occurred as a mutation in a single mite in Sicily; mites are virtually 'clonal' (i.e. genetically identical due to brother/sister mating) and it seems likely that all the resistant mites may have spread from this one mite. Mites have not become resistant because beekeepers have misused treatments. This is evidenced by the fact that mites were originally spread around the world by man and the resistant mites are following the same route - we do not seem to have learnt!

Developing resistance may have an ongoing ‘cost’ to an organism, such as varroa, e.g. growing a thicker cuticle takes valuable resources and this may reduce the mite’s ability to reproduce; but sometimes it may have no cost, e.g. a change to sodium channel. If there is a cost, then withdrawing the pesticide causes the mite to revert to its original susceptible form and the treatment will work again (until resistance develops once more); if there is no cost (as in this case) then mites will stay resistant as there is no advantage in reverting. This is bad news for beekeepers, as it means that once resistance to pyrethroids has become common, then those treatments may be ineffective indefinitely. This suggests that both Apistan and Bayvarol will never work again and beekeepers must look for alternative treatments.

Breeding and Selection for Resistance
No colonies (except for Africanised bees) have been able to survive indefinitely. Some beekeepers have been checking dead mites for damage, hoping that this indicated that bees were attacking the mites, but the damage is actually caused by bees removing dead mites from cells (a percentage die in the cells) - not by bees attacking mites.

 

5.      A Cautionary Tale

Stuart Foster

Following on from Robert Swallow's recent reports and references to "Colony Collapse Disorder", I thought readers might be interested in my recent experiences.

By the middle of last season, I had six colonies of bees but they were all affected to some extent or other by varroa. I had invested in open mesh floors earlier in the season and I could see that the mite drop was significant. Early in July, one of the colonies became queenless and despite my best efforts (introducing a frame of eggs from another hive on 3 separate occasions) the bees failed to produce a new queen. By this time I considered the remaining bees were too old to merge with another (stronger) colony and all I could do was let them die out. At the beginning of September I inserted Bayvarol strips into the five remaining viable colonies and the resultant mite drop was significant. The autumn was very mild and the bees were still foraging well into November. Consequently they didn't take much of the feed I gave them but by "hefting" the hives I was confident that they all had ample stores for the winter. However, on the 26th October I discovered that another colony had died so I was now down to four. On Boxing Day I discovered that yet another colony had died and I couldn't find the queen among the few dead bees that were still in the hive. In January I bought myself a Varrox Vaporiser from Thorne's and on the 13th January I treated the three remaining hives with oxalic acid. The resultant mite drop was incredible with hundreds of mites falling through the open mesh floors but unfortunately the treatment came too late for one of the colonies. However, this time I did manage to find the queen among about 150 dead bees and plenty of stores. On the 4th February I treated the two colonies remaining colonies with oxalic acid vapour again and the resultant mite drop was about ten from each hive. Just to make sure, I treated both colonies again on the 17th March and joy-of-joy, the resultant mite drop was zero. They talk about pride coming before a fall and little did I realise what was to come!

Easter Sunday 8th April was a lovely, warm, sunny day so I decided to carry out the first of my spring inspections. I had seen the bees taking pollen into both hives for about a month previously so I was quietly confident that everything was OK. However, when I opened the first hive there was no brood and no eggs, just a virgin (unmarked) queen with no drones to mate with. At least I had my other hive I thought but when I opened that one the situation was even worse. This time there were no viable eggs or brood and no queen either, just a few patches of drone brood in worker cells that had obviously been laid by worker bees.

So that's the situation at the moment. Did I overdo it with the oxalic acid vapour treatment or is there some other explanation? Will the virgin queen wait until there are some drones around and then mate? Is the queenless colony doomed or do I still have time to insert a frame of eggs donated by some benevolent beekeeper?

 

6.      An Easy Method to Indicate the Status of Queens

Robert Swallow.

A lot has been said and will continue to be said about the techniques of finding queens and I will only suggest that the worst time to try to find the queen is when it is essential to do so, due to imminent swarming, for example. One of the many benefits of this system is that full information is simply presented about the status of the queen prior to opening a hive without reference to notes.

A system which is useful to track queen presence and age/colour can be based on coloured push pins (or perhaps coloured drawing pins). Several retailers fortunately follow the colour code used in beekeeping, supplying pins in selection boxes containing white, yellow, red, blue and green.

A colony without a queen or the necessary eggs or young larvae to produce a queen would be left without any pins, hopefully a vivid reminder of the need for urgent action to resolve the problem. When a queen cell is raised and is occupied three pins of the colour corresponding to that years marking are placed on the front of the brood box.

When the queen has hatched, one of the pins is removed leaving two pins indicating a queen of that colour present and unmarked. The queen is then left in peace to allow mating and for brood to develop to the sealed stage when it is less likely the workers will take exception to the presence of the marking paint on her. Once the queen has been marked, the second pin is removed so that one pin indicates the presence of a viable marked queen of that colour.

The benefit of this system is that you are reminded immediately that a queen needs to be marked in the colony that you are about to inspect and that you can prepare yourself to mark the queen by having the cage and paint immediately to hand prior to opening the colony. If the unmarked queen is not found on this examination prepare fully again on the next inspection.

 

7.      Round and About

Ludlow & District BKA: Saturday 12 May: Apiary Meeting 2.30 pm with Brian Roberts, The Crest, Berrington Road, Tenbury Wells Further details: Andy Vanderhook Tel: 01299 841379(Details: Andy Vanderhook: Tel: 01299 841379)

Oswestry BKA:Saturday, May12 at 3p.m.: Invitation of Mr. K. Everitt. Cwmclyd, Llanarmon Rd., Pandy, Glyn Ceiriog. Demonstration by Mr. C. Critchley. RBI. Further details: G. Jones Tel: 01691 654448

 

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