(Note: I wrote this for sci.agriculture.beekeeping and thought it might be
of interest here. Of course I am always interested in being proven wrong
(that's how I learn), so rebuttals are welcome).
>The Nassenheider evaporator, of which 50,000 have been sold in Germany
>alone, does not kill queens because it releases the formic in a very
>controlled fashion and very slowly over a two to three week period.
Some preliminary Canadian research indicates that there may be very
noticable reduction in honey production when *slow release* methods are
used in the spring.
>The Canadian researchers at The American Beekeeping Federation highly
>recommended it for "hobbiests." I disagree with them. I think commercial
beekeepers can use it far more efficiently than the Canadian system. The
evaporator requires filling only once and uses much less formic. Treatment
costs 25 cents per hive - not bad for treating both mites. The Canadian pad
system requires much more formic and 3 to four trips to the bee yard.
I have a Nassenheider Evaporator in my hand-- and the instructions -- as I
write this. The Nassenheider Evaparator requires either 100 cm2 or 150 cm2
(ml) of 60% formic. Two such units must be used if there is brood in 2
chambers such there is in Alberta in the fall. This totals 200-300 ml of
60% formic.
Moreover, each unit must be placed fairly close to the brood, I understand
that it must be in a half-frame in place of a comb. Therefore, two special
frames are required per normal hive, and they must be inserted in each box
of each and every hive, a time consuming process, that mandates extra
equipment be on hand. The displaced frames must also be toted somewhere
for temporary storage.
Dangerous free liquid formic acid must be carried on the truck and poured
into a special filler bottle every few units. Then the units must be
filled. Safety practice requires use of a respirator, gloves, and goggles
when handling liquid formic. The units themselves are fairly delicate, and
have a wick that is subject to damage in normal commercial rough handling.
The wick must be replaced at each use.
Recommendations are to check evaporation rate after 2-3 days and trim the
wick, if necessary. This means a trip to pull frames and check.
These are hardly simple, quick processes, and require partially
disassembling each hive thrice -- once to treat, and once to check, and
once to remove the unit. Skilled staff is required for each action.
Compare to the Canadian system: Take a known number of meat soaker pads
and place in a bucket with a measured amount of formic. Wait overnight.
Pour off any excess acid. Send almost anyone to a bee yard in a light
vehicle with a pair of plastic or stainless tongs, safety glasses (maybe)
and some emergency safety equipment, as well as a smoker.
The person removes the outer lid, peels back the sack, and with the tongs
places a single pad on each top box and quickly turns down the sack or
plastic. If no sacks or plastic is used, the bees *should* be smoked down,
but I imagine are often not.
The pads are not dripping and no liquid is apparent. There is no potential
for serious leakage. Most people do not wear goggles or a breather for
this since there are not many fumes, and no free acid. Soda and a mask,
and water should be available though in case of some freak accident.
The treatments should be repeated from three to five times at intervals of
anywhere from 4 to 10 days (not critical). Since we often pass yards on the
way to working on others, this method does not necessarily mean more
driving. The visits are very brief.
Using 30-40 ml treatments, the total dose is 90-150 ml (min) or 120-200 ml
(max). This minimum dosage is actually *lower* than the amount needed for
maximum treatment using a single Nassenheider Evaporator. We usually have
brood in two or three boxes in Sept, so we would need two for a total of
*300-400* ml using the Nassenheider Evaporator, but only 200 with the pads.
>> The danger of queen loss by the sudden evaporation from the pads is much
>>
more.
Although there have been some anecdotal reports, they are usually
associated with applying the formic on the floor -- not pads -- or using
incorrect amounts at poor times. When the recommendations are followed,
there is no appreciable loss using pads.
>With the Nassenheider, you can treat at the last honey harvest and leave
>the evaporator in the hive until the first Spring inspection.
This means having a big gap in the frames where the thing sits. This is
likely to cause poor wintering (colony death) here in Alberta.
> This results in much less labor and mileage costs than the pad system. If
> two men are harvesting a thirty hive yard, it adds about 15 minutes to
> remove one brood frame and put in the frame with the evaporator on it.
The official instructions require *two* Nassenheider Evaporators per hive
for my outfit. That means opening the lower brood chamber -- not a simple
task. This doesn't look like a 15 minute job to me. After all, we still
have to fill these things with liquid formic.
>If you wanted to get some Fumidil into them, you could come back a month
later and replace the evaporator frame with a division board feeder filled
with sugar syrup.
Sounds like re-arranging the brood chamber in fall -- a prescription for
hive death where I live. Besides we are far too busy in the fall to fool
around with this.
>The formic works in cold weather on the tracheal mite too so I see it as
>the salvation for Northern beekeeping - we can't all take our bees to
>Florida. There is a whole page on these evaporators in the 1997 Betterbee
>catalogue - they cost about two varroa strips!
Soaker pads cost 1.5 cents each for a total of 7.5 cents -- if we go the
whole 5 trips. We use much less formic, have less danger, cut labour cost
to a trivial amount, and ensure that, since there are multiple visits, that
each hive will get treated at least most of the trips. None will be
accidentally missed.
The Nassenheider Evaporators cost *much* more, use more acid and are not
proven in North American conditions. Moreover, most experts agree that
formic alone will not always control varroa sufficiently that Apistan will
never be needed. Usually there is a recommendation to monitor mite levels
and rotate treatments where varroa is a problem.
Of course, I am not sure about how many of the Nassenheider claims to
believe, since, for one thing, the literature that comes with my
Nassenheider Evaporator claims 'an acaricide effect of appr. 90% was
achieved in sealed brood cells'. (If this is truly the case, then we had
better watch out because the +Tracheal Mites+ in Germany now seek out
sealed brood, and not predominently 1 to 4 day old bees as they do here).
Anyhow, all funning aside, we can use pads spring or fall, save tons of
money and fussing, and still get a good honey crop, something that slow
release methods cannot guarantee when they are used in spring.
And we still have the many thousands of dollars (10,000?) that we would
have spent on Nassenheider Evaporators, if we find that next year there is
a fantastic breakthough.
Allen Dick VE6CFK
Rural Route One, Swalwell, Alberta Canada T0M 1Y0
[log in to unmask] & [log in to unmask]
http://www.internode.net/HoneyBee/
|
