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Good News
As far as I am concerned, the only good
VARROA is a dead Varroa!
The above 'drawing' shows in graphic detail how quickly the Varroa mite has spread across our planet, it is a frightening picture and brings it home to us the seriousness of the situation.
This mite, generally referred to simply as varroa, is specific to honey bees. The natural host of varroa is the Asian honey bee, Apis cerana, which has its own natural defences against the mite. Through movement of colonies, varroa has spread to our own honey bee, Apis mellifera , which as yet has no such defences. If left untreated, infested colonies in the UK will eventually die.
The first outbreak in Britain was discovered in April 1992 in Torbay, Devon.
It has taken just 6 years to become widespread throughout England and Wales with reported cases also in Scotland and now this year, Ireland.
Varroa cannot as yet be eradicated, and as no one can possibly forecast how long it will take Apis mellifera to develop any defences, it remains for us beekeepers to do all that we possibly can to help our bees survive.
Doing nothing is not an option as beekeepers who leave colonies untreated will lose them and cause serious problems for those who are trying to deal with the parasite, because neglected colonies will become a source of infestation for treated and managed colonies in the locality.
My very first live sighting!...
I first discovered the dreaded mite in my colonies during the Spring of 1996 and it was not a welcome sight. Over the years, I have fitted most of my crown boards with clear perspex panels which are a great advantage as I am now able to judge the state of a colony without disturbing the bees.
I keep 'National' type hives and the hive where I first discovered the mite(s) had one brood box and one super, with no Queen Excluder in place.
Her 'Majesty' had made her way up into the warmest place available into the super frames and had laid eggs inside Drone cells which her workers had constructed, attached to the underside of the perspex crown board. The eggs had hatched and from above I was able to see through the clear perspex into the 'top' half of the cells.
I was horrified to find that several cells contained live Varroa mites having the time of their lives inside the still sealed Drone cells. I duly reported the findings to the authorities and the presence of the mite was duly confirmed.
BAYVAROL - To use or not to use?...
I was now presented with a moral dilemma, you will obviously be aware by now that I do not believe in using any form of chemicals if this can be avoided, this applies to both Beekeeping and Gardening. Bayvarol strips had already been inserted by the Bee Diseases Officer in order to confirm the presence of Varroa and I was not very happy about this, although it is fair to say that the 'drop down' count was good.
I waited two weeks before removing the strips (NB. Using gloves to avoid contamination) which were then sealed away. I have not used Bayvarol since that time, but in view of the seriousness of the situation this year, having lost so many of my colonies during the Winter months, I now feel that for the time being at least, using natural methods of treatment are not going to be strong enough to effectively control the mite.
As I do not wish to lose any more colonies during this coming Winter, and in order to give my bees the best fighting chance possible, I have therefore decided to re-use chemical strips with a view to monitoring the drop down count compared with using just natural methods of control.
I do not want to be an alarmist, but it has already been reported that traces of the chemical 'Apistan' have been found in both Wax and Honey, and in my opinion the same could apply to Bayvarol.
I sincerely hope that this is due to misuse of the chemical strips.
(Please see below for further details on method of use).
Importation of chemicals into the UK...
There is a very interesting and informative article contained in the March edition of Bee Craft 1998 concerning 'The medicines (Restrictions on the Administration of Veterinary Medicinal Products) Regulations 1997' which have been amended with effect from 1st February 1998 prohibiting the importation of Varroa treatments that are unlicensed in the UK.
This means that officially, we beekeepers are for the time being restricted to using I believe just one chemical, 'Bayvarol', although I understand that from November 1998 Apistan is to be added to the list of licensed products.
This is indeed good news as it does not take an expert to realise that the Varroa mite could become resistant to Bayvarol. We could end up with 'super' mites which will then be even more difficult to destroy.
This news I am sure will help prevent the mites from becoming resistant to just one treatment as has already happened in many other parts of the World.
Did you know that there are now 'Apistan resistant' mites in Florida and more importantly, even much closer to home in Belgium, Italy, Switzerland and 'France'.
Mites resistant to one varroacide are likely also to be resistant to other closely related substances. Such mites have been shown to be resistant to other pyrethroids such as flumethrin (Bayvarol)
Many mite species, including Varroa, are able to develop resistance to pesticides. This can occur because individual mites differ in their susceptibility to a given substance.
If a population of mites is exposed to a varroacide dose that only kills the more susceptible mites (for example, by using too small a dose), then only resistant mites will survive to reproduce. Over many mite generations this can lead to the development of a resistant population.
You can see therefore why it is so important to alternate the treatments and also the dosage in order to help prevent the mite from developing such resistance.
For example, you could use drone-brood trapping during the Summer months being of course very careful not to allow the drones to 'hatch', which would increase the population of mites. This could be followed by chemical treatment or if you prefer some form of 'natural' treatment in August, (after taking off the Supers) and if necessary a second treatment with a different product the following Spring
Such an approach has several benefits:
Control at several points of the year makes it harder for the mite population to reach a level that harms the colony.
Use of biotechnical methods slows mite population increase and so can help reduce the frequency with which various controls need to be used.
Use of two or more unrelated products will help delay the onset of mite resistance to treatments.
Potential residues in honey
By observing the following simple rules, you can minimise potential residues:
1. Never treat immediately before or during a honey-flow, or while supers are on the hive.
2. Do not use more than the prescribed dose in the hope perhaps that this will have a greater effect, it won't!
3. Try not to apply the treatment for longer than directed as, if this is done, you may be helping the mite to become resistant to the product.
Do not be tempted to re-use the strips after the initial 6 to 8 weeks of use as they may no longer be potent enough, which might then lead to chemical resistant mites.
Instead, use those strips for a short period only in order to monitor the drop down count of the mite.
I only wish there was some test available to find out the strength of the strips after use!
4. Always follow strictly the label directions supplied with all licensed products.
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