 |
Treatments Bayvarol Apistan Apiguard |
Varroa Curse of the Honeybee
|
|
As far as I am concerned,
the only good Varroa is a 'dead'
Varroa!
Have a look at the excellent animated map (shown below) courtesy of Sandra Arlinghaus Ph.D) which shows in graphic detail how quickly the Varroa mite has spread across our planet. It is a frightening picture and brings 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 last year, (1998) 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. Back to top 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. Back to top 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 in (1998), having lost so many of my colonies during the Winter months, I felt that for the time being at least, using natural methods of treatment were not going to be strong enough to effectively control the mite. As I did not wish to lose any more colonies during the coming Winter, and in order to give my bees the best fighting chance possible, I therefore decided to re-use chemical strips with a view to monitoring the drop down count compared with using just natural methods of control. Back to top Apistan... This time, I used APISTAN in order (so I thought) to help prevent the mite gaining any resistance to the strips. However, I have since been informed that there is no advantage in alternating the strips. See this article which explains the reason why! 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). Back to top Resistant Mites... 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'. LATEST NEWS Sept 2001 Resistant mites found in Devon, UK 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. It is important therefore to follow the manufacturers instructions to the letter! Do not leave strips inside the hive for more than 6 to 8 weeks as the chemical may after then, in all probability lose it's potency, which may lead to resistant mites... Back to top Drone brood trapping... 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:
Apiguard
|
