Date: Thursday 25 November 2004
Venue: Church Rooms, Stow on the Wold
Notes for Jeremy Voaden
The evening
began with the video “Beetle versus Bee”: A Film Reportage by Gerald Kastberger
and Otmar Winder (2003 Institute of Zoology, University of Graz, Austria /
Austrian Agency for Health and Food Safety.
The Small Hive
Beetle is native to Sub-Saharan Africa and belongs to the Sac Beetle family. It
lives there with the Cape Bee and Scutellata Bees which can tolerate it. As it
is the protein-rich larvae that the beetle is after, if the African bee colony
feels threatened by the beetles, the colony simply moves on. Our bees, Apis
mellifera cannot do this.
The beetle
lays its’ eggs in cracks in patches circa 1cm. In diameter. The larvae hatch 1
day after they are laid. They are small and burrow into the combs, eating
everything they can-pollen, brood and honey. The larvae excrement transforms
the honey into pap that stinks of rotten oranges. It is unusable. The larvae
destroy everything in the hive and the colony collapses.
Just before
pupating, the larvae leave the colony and burrow into the ground. They
orientate themselves towards the light. Optimum conditions for burrowing are
sandy ground. They can wander up to 80 metres in front of the hive.
Three weeks
later the beetles hatch. They are brown in colour and immediately they:
-Look for a
mate
-Seek
something to eat. They need protein in abundance
…so they move
back into the hive.
In
contaminated hives, they congregate in the frame runners and under the lid or
crown board. This is where the bees try to drive them. However, attempts to
confine them with propolis fail. The Hive Beetle deals with the Guard Bees by
pretending to be another bee and flapping their antennae. If it meets up with a
Nurse Bee, it gets fed larval food this way!
The Small Hive
Beetle reached the USA via container ports in 1997. It took just 3 months for
it to travel from Port St.Lucy on the Florida Coast to South Carolina, a
distance of 120 miles. South Carolina Beekeeper Ally Crosby lost 500 hives in 3
years to the beetle. He found the beetle larvae riddling his honeycomb and
devouring brood and honey cells. Larvae gathered in thousands on the floor of
his hives. It was also first noted in the USA that the beetle survived on
fruit.
By 2002, the
beetle was found in Australia.
By 2003, it
was in Canada.
The epicentre
of the USA invasion has been the South-Eastern states. In South Carolina, every
apiary is affected. As it is a tropical pest, needs at least a semi-tropical
environment to really thrive. It has not yet caused significant problems in the
northern states.
Itinerant
beekeepers travelling back and forth across the USA have spread the beetle.
Whilst attempts are made to strictly control US National borders to prevent
biogenetic invasion, 1200 mile journeys across state boundaries following
pollination contracts are not unusual.
Attempts by
the small-scale beekeeper to protect their hives from the beetle include:
·
The most
important thing is not to leave dirty old hives, frames, pollen combs and dead
hives lying around. Clean and sterilise and store!
·
Some
beekeepers have closed up the regular hive entrance and put in a PVC pipe way
up the side of the brood chamber as a more inaccessible (to beetles) entrance
·
Placed a tin
bowl in front of the hive to collect the larvae when they leave it
It is now
thought inevitable that the beetle will come to Europe by way of bee-trading.
Bee imports are completely un-necessary and we can breed good queens from our
own stocks at home.
Current
European Union trade regulations offer little hindrance to the beetle. So long
as the importer has a valid health certificate for colony or queen, they can
bring it in. The risk of importation on fruit is also thought to be high.
Robin then
shared his top four tips for controlling varroa in the era of the treatment
resistant mite.
1. Treat
with Apiguard and modify your Crown Boards to accommodate
the treatment trays
If you are going to use Apiguard, it won’t fit under the traditional Crown Board edge so put an extra baton round the edge of the board. This extra height permits proper evaporation from the Apiguard tray.
It can also be very useful in Autumn when bees bring in Ivy honey which they can then store on top of the frames and below the crown board. Robin thinks this is the best place for it! Ivy honey is very aromatic and lard-like. It crystallises very hard and so needs a lot of water for bees to use it.
2. Open Mesh Floors
These can have an entrance space which is only 1 bee-space high therefore don’t need mouse guards in winter. This allows for:
·
Lots of ventilation & no
condensation
·
Cappings and faeces falling through
the floor improving hive hygiene
·
Varroa mites falling out of bottom of
the hive. They need to fall over 2 inches to prevent them crawling back in
again.
It is essential to be able to reduce the ventilation by closing up the excess entrances if you intend to us Apiguard to ensure the slow egress of the vapour.
Open Mesh floors eliminate 20% of all Varroa miltes aged 1-4 days.
3.
Insert 1 or 2 Super frames at the edge of the Brood Chamber
Bees will draw
drone comb below the Super frame. Varroa mites gather in the drone comb. When
the comb is capped, cut it out and remove it from the apiary. Do this 3-4 times
per annum. This can eliminate up to 80% of all varroa mites in the hive at a
particular time.
Normally at
the start of the season, place the Super frame right at the edge of the Brood
Nest. Bees like new wax to work on so it is fine to put in frame with new
foundation and the bees will draw out one side. The following week, turn it
around and they can draw out the other side.
4. The Shook Swarm technique
This technique
was originally developed as a method of swarm control but is today commonly used
as a method of replacing brood comb and separating bees from pathogens
contained in the old comb-such as those responsible for foul brood diseases,
chalk brood, nosema and the health problems associated with varroa infestation.