Total control is unlikely to be achieved, the strength and
health of the bees themselves is the best starting point. It is quite
normal to find an occasional adult waxmoth or a few larvae in an
active hive.
Hives that have weak colonies, or too many combs for the
amount of bees to cover are ideal places for wax moths to get a
stronger foothold, in which case the quantity of adults and larvae
found will increase, along with the evidence of damage.
Good beekeeping practice including scraping of burr comb and
propolis from hive and frame woodwork will reduce the opportunity for
wax moths of either species to become established.
Combs in storage are ideal breeding grounds for waxmoths.
Drawn comb is a magnet for eggs to be laid in or on or just close to.
Warm storage temperatures also accelerate the destruction process. If
you intend to store comb out of the hive, you must protect it in some
way.
'Wet' storage of extracted comb has some merit from a moth
control/avoidance point of view, instead of returning extracted
supers to the bees for cleaning up, they are left with the small
residue of honey that exists after extraction. I have personally done
this successfully, but it causes a second set of problems in that any
crystalised honey already in the comb when they are used again next
season will seed early crystallisation of the subsequent crop.
Furthermore any cells around the fringes of the comb that contained
honey that was not fully evaporated may have fermentation occur in
the residue, which can cause dysentery when the combs are returned to
the bees.
Irradiation with gamma rays will kill all developmental
stages including eggs, but costs are high and you still have to find
a suitable storage container, that is totally moth proof, to house the
combs after they have been sterilised.
Various fumigation methods can be used, but care must be
taken that no remnants of fumigant are left impregnated in the wax.
And of course adequate precautions must be taken to avoid inhalation
of the fumes by human operators. I can also mention here two methods
that I myself am not familiar with, but others may wish to follow
up... Ethylene oxide, and Phostoxin (the latter in Australia) have
been used for this purpose.
Acetic acid fumes have an effect and the method of use is
the same as for pdb crystals, but the saucer is filled with 80% acetic
acid instead of crystals. The acid is very corrosive and will attack
metal fittings and fasteners. This kills the egg stage as well as all
others and is useful to sterilise against
Nosema spores.
Sulphur dioxide SO2 has been used,
methyl bromide fumigation is offered by contractors, but it
requires comb storage rooms that are completely moth tight. I believe
this method gives protection against many diseases of bees as well as
wax moth infestation.
Naphathlene (moth balls) are sold for protection against
the clothes moth. Some sources say that they are not effective against
waxmoth, but I have had several reports from individuals that have
used them and claim success. I have used them in cupboards indoors to
store frames fitted with foundation or starter strips. The few larvae
that I have found in these cupboards were dead, but that could be the
lack of protein available, just as easily as action by napthalene.
Paradichlorobenzene (PDB) can be obtained as loose crystals,
in bucket sized quantities, from the appliance trade or occasionally
at hardware stores. It sublimes to a gaseous state above 20°C,
the gas itself is heavier than air. It does not kill waxmoth eggs and
you need to be sure you have a continuous fumigation in areas
subjected to high ambient temperatures as the crystals may evaporate
entirely. Beeswax comb will absorb the smell of PDB, see the page
'Combs that smelled of PDB',
you should air combs very thoroughly after storage before using them
on bee colonies and particularly if you are intend to hive swarms on
them.
Build a stack of hive boxes until it is 2 Metres (six feet)
tall and tape over the joints with parcel tape. Place 100 gm of
PDB crystals on a saucer that is resting on the frame top bars in the
topmost box. Or they can also be put in a paper envelope and fitted to
the inside of the box at the top of the stack with a drawing pin
(thumbtack). If the ambient temperature is high, the crystals may
need replacing.
PDB is not suitable for fumigating capped honey or
sections.
Carbon Dioxide (CO2) can be used to exclude air,
from comb honey that is intended for sale as well as for storing
drawn comb in sealed containers or comb cupboards.
Heat... This needs close temperature regulation ( -0°,
+2°) and the air needs to be circulated in the enclosure by
several small fans to ensure even-ness of temperature distribution.
47°C for 85 minutes is required.
Freezing can be used for comb honey or empty combs of any
type -15°C to -20°C for 72 hours is my 'belt and braces'
recommendation, but I have seen shorter times and higher temperatures
quoted. If empty comb is used and the cold air is rapidly circulated
by fans, much shorter times, say 5 or 6 hours can be used.
Bacillus Thuringenisis (BT)(Certan®) is available in UK and
is a microbial bacteria that can kept alive by culturing in milk after
macerating affected larvae.
DIY Moth traps will help, but
will not give total control.
Biological Control... Trichogramma wasps that are used
commercially in green houses will control wax moth larvae, but they
have to reach a particular size before the wasps will parasitise them,
so some damage to combs is inevitable before control is gained.
This post was made by David Brandon to a discussion group...
"I have found that by placing a layer of tobacco leaves between boxes
of brood comb (in storage) and placing a lid on top, I no longer have
problems with wax moth."
Percussive shock... I heard a story from an old timer that
said waxmoth were susceptible to the sharp blast of pressure caused
by firing a blank starting pistol inside a hive body. I tried this out
on the occasion covered in the
bucket of waxmoth saga.
I used .22 rimfire blanks and 9 mm black powder blanks. Both
sizes caused a few adult moths to fall out of the boxes stone dead
with their legs in the air. When I tried this I did not have the
presence of mind to fire duplicate shots in the same box or to fire a
9 mm after firing a .22. Although this appears to work it is not
cost effective and is time consuming.
Dessicating atmosphere... It is thought that wax moth eggs
need a moist atmosphere to hatch. Therefore the addition of dessicants
to the various methods would probably improve them as treatment
against the waxmoth.
Originated... 10, 14 June 2002,
Transferred to New Domain... 23 July 2004,
