prevention of beeswax combs from wax moth damage
Apeldoorn, The Netherlands
moth is a highly destructive insect that attacks and destroys beeswax combs
especially those in storage. The moth itself is not a problem; it is the
larvae that do the destruction. The moth loves old combs and visits stored
combs which are unprotected and could reduce them to a mass of webbing very
rapidly. Combs in storage are ideal grounds for the breeding of wax moths. A
beekeeper should take preventive action to protect his unused combs against
wax moth attack during storage in winter to avoid losing valuable combs.
Wax comb damaged
by wax moths
Courtesy of Dale R. Rohe)
two ways of protecting unused combs against wax moth infestation:
combs in moth-tight cupboard or keeping them in sealed polythene bags.
The combs should not be removed from the bag until they are required to
be put back on the hive.
boxes of empty combs atop strong colonies.
beekeepers in the UK protect their combs by wrapping them in newspaper
the moths dislike its smell, this is done as soon as combs are removed from
hives. This method has been claimed to give good results.
several effective chemical fumigants being employed in treating wax moth, of
which the following to be recommended for their safety, convenience and
Paradiclorobenzene is a fumigant that is widely used to protect stored combs
against wax moth. It is a white crystals substance that vaporizes very
slowly and produces a gas that is heavier than air. Paradiclorobenzene is
non-flammable and non-explosive and is safe to use but it should not be used
to fumigate combs of honey that is to be used for human use. Honey absorbs
the odour of PDB and such honey becomes unfit for human consumption.
Paradiclorobenzene kills the adult and larvae and does not kill the eggs of
the wax moth.
The use of PDB for controlling
have been extracted are returned to the colonies to clean them from the
remaining honey. After a day or two they are taken off and stored in hive
bodies (supers). Supers full of combs are stacked tightly in a stack of no
more or higher than five hive bodies. The joins between the boxes are sealed
with tape or paste paper to keep in the fumes. 85 grams or 6 tablespoons of
PDB crystals or powder is put on a piece of paper or cardboard 15cm square
placed on the top of the frames in the top super. The top super is closed up
with outer cover. As PDB evaporates gradually; the fumes will sink down
through the boxes, this kills larvae as they hatch from the eggs. The PDB
should be replaced when all the crystals have evaporated. The constant
presence of PDB in the stack will repel moths and prohibit egg laying and
prevent infestation during storage. The treatment should be continued at
intervals of 2 or 3 weeks all winter.
fumigated combs should be aired for at least 24 hours before they are put
back in bee colonies in the spring. This is usually sufficient to remove the
chemical fumes. The bees will not easily move into combs that smell of PDB.
Stacked boxes of
combs being fumigated
(Photo by Paul Hooper, Beekeepers
Association of the ATC, Australia)
80% can be used for controlling wax moth in stored combs and for cleaning
combs from Nosema spores. Fumigation with acetic acid will kill moths and
their eggs and larvae. After the honey is extracted, boxes of combs are
piled in stacks, no more than five high. The seams between the boxes are
taped with paste paper to form an air tight seal. A wad of cotton wool 15
by15 cm or similar absorbent material soaked in 80% acid is placed on top of
the uppermost frames in the stack before the lid is sealed, using 25 mills
80% acetic acid per box in the stack. The top of the stack is covered with a
hive roof and the stack is left undisturbed for two weeks. The fumigation
can be repeated at intervals of 2-3 weeks.
must be handled with caution to avoid splashing the liquid on the hands or
on the face or into the eyes. Splashes on the hands should be washed off
fumigation the boxes of combs should be aired for about two days before they
Sulphur (Sulphur dioxide, SO2)
an effective repellent used in controlling wax moth, it forms fumes (sulphur
dioxide, SO2) on burning and it is highly volatile. Sulphur kills adults and
larvae but is ineffective against eggs.
are treated in the boxes in which they are stored. For this, a top cover of
a hive is placed upside down on the floor and an empty box is placed over it
to keep the combs from too close contact with the burning sulphur. A vessel
or saucer containing burning pieces of coal and sulphur powder is placed in
the empty box, using 2 ounces (approximately 60 grams) sulphur powder for
every stack of five boxes. Supers or boxes of frames no more than five high
are placed above the empty box with burning sulphur and the top box is
covered with outer cover after stopping its ventilation holes. The seams
between the boxes and any gaps in the stack through which the fumes might
escape should be sealed with tapes or gummed papers. Several treatments are
repeated with an interval of a fortnight to destroy larvae that hatch during
storage. The treated combs must be aired until the smell of sulphur is no
longer perceptible before they are put back in the hives.
are sold for the prevention against cloth moth in cupboards. Some
individuals use these balls to prevent wax moth infestation from destroying
the combs over winter. Some say that they are not effective against wax
moth, some that have used them claim success. Others disencourage the use of
them because Naphthalene leaves harmful residues in the wax and advise the
use of those moth balls are made from Paradiclorobenzene.
containing the frames wax are stacked together with a sheet of newspaper
laid between supers with a mothball is on each sheet of newspaper to prevent
the combs placed above it and to inhibit movement of wax moth adults.
must be thoroughly aired out for several days before use.
Certan is a
biological insecticide used for the prevention and control of wax moth
damage for both stored combs and live colonies. It is a suspension of spores
of the bacterium Bacillus thuringiensis. Its commercial name is:
B401. It is mixed with water and applied as spray on each side of the combs.
It can be applied before storage in the fall or before putting combs into
the hives in the spring. Certan is non-toxic and does not harm bees or
contaminate the honey or wax. The preparation of Bacillus thuringiensis
is effective against wax moth larvae; when a larva eats the spores they
germinate to produce a lethal toxin in the gut that kills the larva.
be added here that a British beekeeper claimed that he had no longer
problems with wax moth by placing a layer of tobacco leaves between boxes of
combs in storage and placing a lid on the top.
It is also
said that the herb wormwood (Artemisia absinthium) is reputed to deter
climates, wax moths are more likely to be a serious problem. Warm
temperatures ensure a viable wax moth population all year round and
accelerate the rate of moth’s development and the destruction process in
stored combs. It is necessary to inspect the stored combs regularly in warm
weather and during hot summer. If a slight damage, the infested parts are
cut out and larvae destroyed. If severe infestation, the wax are scraped off
the frames and all wax is burnt. The frames are scorched with a blow torch
or soaked in hot water containing washing soda or a household detergent
compound. The hive body is also cleaned up and scorched.
with cold winters or mountainous areas above altitudes of 1000m, wax moths
do not cause much damage because moth’s development comes to a standstill at
temperature below 9C and all stages of wax moth are destroyed by a severe
frost or freezing.
& Kim Flottum, Honey Bee Pests, Predators and Diseases, 1997
Graham, The Hive and the Honeybee, 1992, Dadant & sons
and its control, Department of Agriculture and food, Australia Note: 252 in
By Doug Someville, Prime fact 658, in