Over the past few days the debate about mites and their treatment has
rumbled on, with many contradictory positions being taken up and
arguments advanced by most parties to support their views. Some of these
views have been sensible and practical, whilst others are bizarre and
seem to be founded on some personal 'bee in their bonnet' rather than
common sense.
The first point I would like to make is that I cannot see how the
experience with acarine mites teaches us anything much about varroa
mites. To lump them together and assume that because something happened
with acarine it will eventually happen with varroa is false. They are
entirely different beasts who happen to be mites; the only thing they
have in common. It is like saying that "bears and mice are both hairy
mammals and thus alike. Both are pests to beehives and the treatment for
one will eventually control the other." Obvious nonsense. Some people
are drawing these kind of conclusions and I feel that is dangerous.
Varroa is a very serious pest indeed and regarding it in even a slightly
casual manner WILL bring you disaster once it reaches you.
The old term 'Isle of Wight disease' has also recently appeared. It is
fair to point out that there is still to this day some debate as to
exactly what this was, and although the balance of opinion points to
acarine (with which conclusion my father and myself concur), some
authorities are more in favour of nosema. It could well be that it was a
much more complicated situation than that, with the first wave of
acarine, already damaging in itself, being added to by a range of
opportunist complaints coming along to finish off already weakened
colonies, and indeed this 'multiple infection' scenario has also been
mooted by some experts.
The apparent lack of current problems due to acarine in many areas is
also occasionally being put down to a loss of vigour in the mites. My
own experience tends to refute this. We have, back in the 70's and 80's,
imported several different strains of bee from USA and New Zealand.
Certain strains, particularly caucasians from the southern states of
USA, were decimated in a relatively short time by acarine mites, which
should not have happened if the mites had lost their vigour. Other
strains were largely untouched. I believe that some strains are more
tolerant than others and that in all countries affected by this mite a
population will gradually emerge which is capable of living with it.
Climatic factors could also play a part in this, with bees tolerant of
these mites in say Florida or Texas not being able to tolerate them so
well in say Vermont or Washington (or Scotland) and possibly the
opposite is also true, which could account for the poor initial
indications with European strains when tested in the USA.
There has also been debate of what is a pesticide and what is not. An
argument has been advanced that anything used to kill a certain pest is
a pesticide, which, if correct, therefore must include all things which
are physical, chemical or biological killers. In real life this would
therefore include organophosphates in the same category as mouse traps:
both being deemed to be pesticides. Perhaps in a narrow sense this would
be correct, but common sense dictates otherwise. I have great difficulty
considering Dr. Rodriguez's mineral oil as a pesticide, but some other
chemicals most certainly are. I am also extremely wary of those who
regard 'natural' as automatically good and 'synthetic' as automatically
bad.
This bring me on to the climate of hysteria surrounding Apistan and
Bayvarol. The active ingredient is fluvalinate, a synthetic pyrethroid.
Pyrethroids are the substances, with insecticidal properties, derived
from crysanthemums. It is quite possible, and indeed widely practiced by
some gardeners, to crush up crysanthemum leaves, make an infusion, and
spray it on plants as a completely natural form of pest control. It
could even be deemed organic. Dosage levels are uncontrolled but no-one
would mind because the treatment is 'natural'. Why then do we have such
a difficulty in coming to terms with what is more or less a man made
copy of these substances, and administered in correctly regulated
amounts. Although there are now some fairly benign treatments being
proposed I cannot see why fluvalinate is considered so bad by so many
correspondents. The nature of the substances are such that, in aqueous
environments, they quickly degrade away to non-existent levels, but in
oil based environments, such as wax, or plastic strips, they are readily
preserved. The idea of producing POISONOUS honey from hives which have
been treated and have residues in the wax is largely a myth, and
certainly a gross over-reaction resulting from misconstruing the nature
of the substances involved, and is, commercially, a very dangerous line
to be voicing. Treat at the correct times, keep your honey clean and
properly filtered and/or sell comb honey from virgin wax only and you
will not have a problem.
In the UK certain high profile individuals are actively promoting formic
acid as a 'natural' alternative. This definitely is a noxious substance
with a far longer active life in honey than fluvalinate, but even so
will have its place, in properly regulated dosages, in a mixed program
of varroa treatments.
I do not yet know enough about mineral oil, which is currently the
subject of so much debate, to pass informed comment on it, but it does
seem to be a relatively harmless substance. However, almost all the
other varroa treatments being suggested, such as drone trapping, are, in
my opinion, best used as supplementary measures to support the principle
treatments. One thing is clear to me: we do not have the 'leave it
alone, it will be alright in the end' option with varroa. NOT treating
your bees is the cruel option here, because if you don't they will
almost all die, and then you will eventually have no bees in any
quantity worth speaking about. It WILL get you in the end, even the 'MY
bees are fine, even though everyone around me has varroa' people!
I sure would like the 'Thou shalt not treat, for then we shall achieve
true immunity' brigade to come and tell my 16 employees why they are out
of work, and my 60 or so suppliers why they won't get paid, and my 40 or
so fruit farmers dependent on us for pollination why they will have a
bad crop for at least the next 20 years. That would be the inevitable
conclusion of a no treatment regime for varroa. The development of truly
varroa resistant or tolerant strains is a highly specialised field
requiring many many years of work, without guarantee of success. To
think that we could do it simply by removing treatment and breeding only
from survivors is flirting with catastrophy.
Similarly, whilst appreciating the logic behind the idea of not treating
for diseases and pests which are not present, I cannot agree, for
reasons of commercial neccessity, with such a general remark. Part of
good medicine and management is preventing problems building up to the
point where radical treatment is needed. A simple and somewhat crass
example would be that you fit mouse guards BEFORE you have a mice
problem, not once these pests are there. Similarly we would blanket feed
ALL our colonies Fumidil-B if it was evident that nosema was on a rising
trend in our apiaries, thus preventing an epidemic of it. Once varroa is
present in our area we will need to treat ALL colonies at key times,
again to prevent heavy losses. For the security of my family and my
employees we have no alternative. Sensible preventative measures are
sound economically and, when not used indiscriminately, need not cause
premature development of resistance to the treatment.
As always, the above is my opinion based on the facts as presented by
those who know technical matters better than I do, supported by our own
observations. If you have had the stamina to get this far without
falling asleep through boredom, thank you for your time!
--
Murray McGregor,
Denrosa Ltd
Victoria St.
Coupar Angus
Perthshire
Scotland
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