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by ERIK OSTERLUND
Sweden
honeybee@elgon.se
The Elgon bee is a combination
bee bred according to Buckfast principles, with a marked influence
of the East African Mountain bee
Apis m. monticola. There have been reports of the work with
this bee in American Bee Journal since the start of these
breeding efforts in 1989.(1)
Bornholm in the Baltic
In the May 1998 issue, I began to tell the readers of this magazine
what was being done with the Elgon bee on the island Bornholm
in the Baltic. Two apiaries of Poul Erik Karlsen were treated
for the last time in autumn 1994. Almost all of the rest of his
colonies were treated for the last time in autumn 1995. In 1998
he successfully wintered 200 colonies. In the May issue of 1999
I mentioned that Karlsen had treated 90 of the wintered 200 colonies
with 200 - 250 ml of 85% formic acid evaporated from soft boards.
One reason for this was to get a picture of the number of Varroa
mites in the colonies. One hundred and ten colonies were not
treated at all, as usual for several years. The average total
number of mites in the colonies in autumn 1998 could be calculated
to average around 1500 mites.
Of the 90 colonies, 87 died during the winter 1998/1999 and spring
1999. Of the 110, one died due to mice. Explanation? The acid
affects not only the mites, but also the bees to some extent--probably
more if the bees already are affected through a number of mites
in the colony that is over a certain level. That's why in a strategy
where formic acid is used, it is very important to keep the number
of mites very low throughout the whole season, so that the bees
that will form the winter cluster will be as little negatively
affected as possible.
Today Karlsen is wintering about 100 colonies, as he is getting
older and has some back problems. Every year, however, he always
makes a good number of nucs that will form mating nucs, new colonies
for himself, to be sold, or to be combined with colonies that
have failing queens.
In the beginning of the 2000 season he saw a few colonies that
didn't develop well enough, maybe due to mites. As soon as he
had new queens, they got a new one. This is the way he has solved
this kind of problem for a number of years now. You can say the
treatment he uses is selection and breeding.
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Colony A superseded
its queen and the new fresh queen handled the mites.
Photo: E Osterlund |
Karlsen is helping a growing number of beekeepers with new colonies.
One friend has purchased a new colony twice from him, but both
have died from what he thinks are varroa mites. Is this just
bad luck getting the poor variants that always show up in all
breeding? Maybe the apiary site is part of the explanation. It
is situated in the shadows of a big tree at the bottom of a hill.
Karlsen said this place always felt a little cooler than the
surroundings. Maybe it is such a place as was described in a
lecture in Tucson 10-12 April 2000.(2)
Where you place your bees seems to affect the mite growth.
The number of honey bee colonies is still very low on the island.
The average honey crop the season of 2000 was said to be between
0 and 25 kg. Poul Erik Karlsen had an average this same season
of 48 kg.
In October I visited Karlsen and asked him to show me the worst
colonies he could find and the best concerning being affected
by varroa mites. He showed me several strong colonies on two
stories, in a number of apiaries, and also a number of new good
looking colonies made up the same year. In two apiaries he had
one colony in each he had had under observation to see what happened.
Both were in June/July dwindling on one box with too many "wingless"
bees. Karlsen sometimes doesn't give such a colony a new queen
right away, to keep it with mites for a while, as he sometimes
wants a colony with many mites for test purposes. If he doesn't
"save" a few such colonies, he happens to find, he
will have problems finding colonies with too many mites, when
he "needs" them. For example, if he really wants to
test a new eventual breeder queen, he can put it in a hive with
a lot of mites, to see if the queen can handle the situation.
That's what he has done more than once. In 1999 he put two sister
queens in two such colonies he had that year. One of the sisters
did well and that one Karlsen used as a breeder last season.
The other one failed.
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The new queen
in Colony A with some healthy brood and bees in October.
Photo: E Osterlund |
One of these two colonies (A) failing in 2000 had an old queen.
That colony had been a good colony for a number of years with
this same queen. The other failing colony (B) Karlsen had obtained
from a friend who originally had purchased it from Karlsen. His
friend treated with formic acid, but perhaps didn't treat his
colonies well enough to keep the mite level low the entire season
last year. Karlsen didn't know the status of these colonies when
I visited, but they had to have had strength enough for him to
decide to feed them extra sugar for winter prior to my arrival.
Anyhow, it was interesting also for him to check them now. Colony
A was a strong colony now with no sign of any "wingless"
bees. What had happened? It was late in the season, but there
was some brood left, but no obvious sign of varroa. We found
the queen; it was a new one. The bees had superseded the old
one themselves. A new queen with rich amounts of pheromones and
maybe mated to drones with good genes--was that the explanation?
Also, probably a period without brood when supersedure was occurring
helped reduce varroa numbers. Colony B looked the same, but there
we found a few "wingless" bees. However, we had difficulties
finding any varroa in the few patches of brood. They had also
superseded their old queen. Had the formic acid applied last
autumn also affected the pheromone production of their queen?
We checked a two-story hive that Karlsen thought housed a good
colony, as it superseded its 3-year-old queen last year. He had
bred from that colony, No. 482, as discussed in the May 1999
ABJ article. It had shown mites in spring each year, but
had handled the situation well. Her daughter was obviously a
poor variant, as the colony now surprised Karlsen because it
was just a small remnant with many wingless bees and visibly
many mites. "I will kill it tomorrow," Karlsen said.
I was not surprised. There has to be some on the negative side
among all variations of descendants, especially from a colony
that had shown visibly many mites during a period of the season.
I told Karlsen to watch out for the other daughters of No. 482.
For Poul Erik Karlsen, the Varroa mite today is just another
"disease" that "helps" him to avoid the worst
colonies and select the best ones from which to breed--no big
problem at all actually. Karisen and I have been discussing the
size of the bee and the cell it's born in. For those interested,
it can be noted that the Elgon bee in general is smaller than,
for example, the Buckfast. The cell size Karlsen uses currently
is 5.3 mm. He molds his own foundation.
Beekeeper A in Skane
In the very south of Sweden, in the county of Skane, two
beekeepers wanted to test their Elgon queens thoroughly. They
therefore made up an apiary each, quite isolated from other bees.
Beekeeper A made 10 nucs in 1997 from big colonies treated the
last time in autumn 1996 with Apistan strips during 6 weeks.
In 5 nucs he put Elgon queens; in the other 5, he put Buckfast
queens. By the autumn of 1997 he had already started seeing a
few wingless bees in the 5 new Buckfast colonies.
In 1998 nothing special happened with the colonies. They gave
a normal crop and wintered normally. In 1999 the colonies appeared
to be normal, too, with a normal crop and wintering--no wingless
bees. In 1999 naturally fallen mites were collected during 14
days in the first part of June. In the Elgon colonies there was
a daily downfall of 14-28 mites, average 22. For the Buckfast
39-67, average 49. Honey crop--Elgon 41-51 kg, average 45 kg.;
Buckfast 43-53 kg, average 49 kg. The fifth Buckfast colony had
problems with its queen, remained small throughout season and
gave no honey. It died during winter. Two other Buckfast colonies
and one Elgon colony also died during winter/spring 1999-2000.
Half of the frames were full of food, but no bees were left in
the colonies. (See Figure 1.)
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In spring 2000 the remaining colonies developed well, but not
as good as the other apiaries of Beekeeper A, as the spring flow
in this apiary was not very good. During 16 days in May-June
2000 natural downfall of mites was collected. For Elgon the daily
downfall was 25-34, average 30. For Buckfast 44-49, average 47.
In June, Beekeeper A discovered some wingless bees in all the
colonies in this apiary. He now stopped his test. The foundation
A uses has a cell size of 5.4 mm.
Beekeeper B in Skane
The other beekeeper
in the very south of Sweden, beekeeper B, also started a 10-colony
test apiary in 1997 with Elgons and Buckfasts in a similar way
as beekeeper A. The test site of B had a better spring flow and
a good main flow. It was placed high up on a slope, but still
protected from most wind. B did not collect downfall of mites
in 1999. The honey crop that year was an average 60 kg for Elgons
and 45 kg for Buckfasts. All colonies looked strong and normal
when wintered in 1999. All "pure" Buckfast colonies
were gone in spring 2000, some of them leaving full frames of
food and no bees. During 18 days in May-June natural downfall
was collected. It was 5-21 in daily downfall, with an average
of 14. Colonies with the largest number of mites were observed
to have the biggest bees. The colony with the smallest number
was observed to have relatively small bees. A number of queens
are made from this colony. They are all smaller than average
in size. Their progeny is small in size, in spite of the fact
that they were reared in 5.5 mm cell size.
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Part of the test
apiary of Beekeeper B.
Photo: E Osterlund |
Another mite downfall was collected immediately after the first
18 days. Now the daily downfall was measured to be 6-25 (multiplication
with 120 gives the total mite population to be about 700 - 3000
in these colonies at that time), with an average of 16. (See
Figure 2.)
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In October 2000 I visited beekeeper B and he took me to his test
apiary, so I could check the colonies there. I observed the colony
with the largest number of mites, to have two groups of bees
concerning size - one with big-sized bees and one with small-sized.
I draw the conclusion that this could be due to the fact that
the colony had superseded their queen in 2000 and that the new
queen could be mated, at least partially, to small drones. All
the colonies in the apiary were strong and looked very healthy.
All the surviving colonies had superseded their queens themselves,
some in 1999 and the rest in 2000. Is the size of the bees part
of the explanation for the relatively long survival of these
colonies? Is 1000-3000 mites a 'normal' number of mites in "mite-tolerant"
bee colonies?
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E4, the colony
with Beekeeper B which had so few mites and was strong and healthy.
Photo: E Osterlund |
Beekeeper C in Smaland
A little north of beekeeper
A and B another beekeeper, called C, received four Elgon queens
from me in 1999. He put them in nucs made from bees and brood
frames from some of his ordinary colonies. They expanded enough
to be able to be wintered. He didn't use any treatment against
the varroa mite in these new colonies in the autumn of 1999.
His other colonies were treated with Apistan in autumn 1999.
In spring 2000 he used drone comb to trap mites in all of his
colonies. He thoroughly looked for mites in the removed drone
comb. In the drone comb taken from the colonies treated with
Apistan in autumn 1999 he found some odd mites. In the drone
comb from the new colonies, started as nucs in 1999, he couldn't
find one single mite, though he looked carefully. Of course,
they had mites, but these results tell us that if it wasn't the
Elgon queens causing the low mite count, then making nucs is
a very effective method in getting new colonies for next year
with a very low level of mites. Even if you use brood combs when
you make the nucs. Probably the correct answer involves effects
from both the Elgon queens and from making nucs.
Israel
The first positive
tests came with some pure Elgon colonies and the first cross
(F1) Elgon colonies and this was reported in the May 1999 issue
of ABJ. In autumn 1998 new tests were started with F1
Elgon colonies, Buckfasts and two different Italian strains.
Colonies were established in three apiaries. No chemical treatment
or any other kind of treatment was performed. After one year
the tests stopped in two apiaries due to high numbers of mites
combined with uncertainty of how to compensate the beekeepers
if many colonies should die. In one apiary with originally 33
colonies the test continued. This apiary originally had 11 F1
Elgons type A (Group A), 11 F1 Elgons type B (Group B) and 11
Italian colonies type Zrifin (Group C).
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Normally beekeepers requeen every year in Israel due to the harsh
environment and year-round brood rearing. So, in autumn 1999
all colonies were requeened in the test apiary. F1 Elgon colonies
received new Elgon queens mated to Italian drones. Italian colonies
received new Italian queens. The mite level was high. Chaim Efrat,
who gave me this information, said that shortly after the introduction
of the new queens, the colonies looked healthier. He suspects
that the procedure of requeening itself is positive for the colony's
ability to fight the mite.
During winter some colonies disappeared. A control group of 15
Italian colonies that were treated with chemicals twice a year
was kept in the test apiary; called Group D. In July 2000 some
of the colonies had superseded their queens. In autumn 2000,
the colonies were requeened again in the test apiary, this time
with some Elgon queens mated with Elgon drones.
They hope to be able to secure
a number of colonies, Elgons and Italians, that can be used as
breeders to develop a more varroa-tolerant bee adapted for their
type of climate. The cell size in Israel is 5.6-5.7 mm.
Comments
With all these experiences
during these years, from Bornholm and from the south of Sweden,
it would be wrong not to say that Elgon bees are more tolerant
to the Varroa mite than ordinary bees. All Elgons are not alike
in Varroa tolerance, like all other bees. It is also quite obvious
that you can make it easier or more difficult for the bees, whatever
type of bee you have, by how you manage your bees. Also, the
climate has an influence. There were many research reports on
this issue presented at The Second International Conference
on Africanized Honey Bees and Bee Mites in Tucson 10-12 April
2000.(3)
If you want to take advantage of the bees' own fighting ability
against the mite to the highest degree, you can't use any chemical
in order to be sure not to have any interference with the natural
varroa tolerance of the bees. Chemicals don't only have an effect
on the target pest. A whole, small scale or large scale, ecological
system with possibly many different kinds of "bugs"
and microbes are affected in a way that, in practice, is impossible
to know beforehand. Sometimes it may even result, a short time
after the treatment, in an even better environment for the "bug"
you wanted to get rid of.(4)
A strategy taking care of the natural tolerance of the bees has
to be developed. Eric H. Erickson has done this.(5) There's room for more such research. Erickson
has also been involved in research concerning the possibility
that smaller cell sizes of the wax comb can help the bees against
the mite.(6) As far as I know, there are only two
studies published in this field.(7)
The first with positive input and the second with negative. For
a "full scale field study" you could call on the experiences
of Ed and Dee Lusby in Tucson, Arizona, which give positive input
on small cell size.(8) There is certainly room for more research
in this area.
Today I dare to say it is possible to achieve bees that are tolerant
to the Varroa mite, not only in one odd place, but in most places.
I have understood there are more bees than just Elgon bees that
have higher tolerance to the Varroa mite. The Russian bees imported
into the USA are another strain, a strain that in Germany also
now has been confirmed to be more Varroa tolerant.(9) Still another example is the bees developed
by Erickson in Arizona.(10) However,
to really preserve tolerance I have no doubt about it that strategies
without any chemical have to be developed.
A Varroa-tolerant bee is achieved, not only through breeding,
but also through management methods adapted to the environment
where you live. It would be most valuable in todays situation
to see more research funds used for integrated management and
breeding systems for different environments.
References
1) Osterlund, Erik, 1991. Exploring Monticola - Efforts to find
an Acceptable Varroa-Resistant Honey Bee. Am. Bee J. 131:49-56.
Osterlund, Erik, 1993. The Elgon Bee - a Hobbyist and
Commercial Bee With African Genes. Am. Bee J. 133:504-507
Osterlund, Erik, 1998. Varroa Doesn't Kill Bees, But Virus
Does! And what has happened to the Elgon bee? Am. Bee J. 138:377-381.
Osterlund, Erik, 1999. Do We Have Varroa-tolerant Bees
in Europe? Am. Bee J. 139:369-373.
2) Ostiguy, Nancy and Sammataro, Diana,
2000. Using Environmental
Factors to Manage Varroa Mite (Acari: Varroidae) Levels in Honey
Bee (Hymenoptera. Apidae) Colonies. Second International Conference
on Africanized Honey Bees and Bee Mites, 10-12 April 2000,
Tucson.
3) Sammataro, Diana, Ostigny, Nancy,
Finley, Jennifer, Frazier, Maryann, Camazine, Scott, 2000. A New IPM Approach to Manage
Varroa Mite (Acari: Varroidae) Levels in Honey Bee (Hymenoptera:
Apidae) Colonies, Second International Conference on Africanized
Honey Bees and Bee Mites, 10-12 April 2000, Tucson.
Vorisek, Fritz E, Webster, Thomas C, Thacker, Etta M, 2000.
Control of
Varroa jacobsoni with Bottom Board Traps in Honey Bee
Hives, Second
International Conference on Africanized Honey Bees and Bee Mites,
10-12 April 2000, Tucson.
Webster, Thomas C, Thacker, Etta M, Vorisek, Fritz E, 2000.
Measurement of live Varroa Jacobsoni mitefall in Honey
Bee Hives, Second International Conference on Africanized
Honey Bees and Bee Mites, 10-12 April 2000, Tucson.
Velthuis, Hayo H W, Kraus, Bernhard, 2000. The Impact
of Humidity and Temperature Gradients in the Brood Nest of Honeybees
on the Reproduction of Varroa jacob-soni: Laboratory Observations,
Second International Conference on Africanized Hone)' Bees
and Bee Mites, 10-12 April 2000, Tucson.
Velthuis, Hayo H W, Kraus, Bernhard, 2000. The Impact
of Humidity and Temperature Gradients in the Brood Nest of Honeybees
on the Reproduction of Varroa Jacobsoni: Field Experiments,
Second International Conference on Africanized Honey Bees
and Bee Mites, 10-12 April 2000, Tucson.
4) Carson, Rachel, 1994. Silent Spring (Chapters 15 and 16), Houghton Mifflin
Co (Pap); ISBN: 0395683297.
Swift, Fred C., 1991. Effects of Fenvalerate on Control
of European red Mite (Acari: Tetranychidae) on Peaches with Acaricides,
Journal of Economic Entomology, vol. 84, no 4:1348-1352.
5) Erickson, E.H., Hines, L.H., and Atmowidjojo,
A.H., 2000. Producing
Varroa-tolerant Honey Bees from Locally Adapted Stock: A Recipe,
Am. Bee J. 140:659-661.
6) Erickson, Eric H., 1997. Helping Honey Bees Fight Mites, Agricultural
Research magazine, May.
7) Message, D, and Goncalves, L.S., 1995.
Effects of the size
of the worker brood cells of Africanized honey bees on infestation
and reproduction of the ectoparasitic mite Varroa jacobsoni
Oud. Apidologie 26:381-386.
Davidsson, Mia, 1992. The influence of cell size in Varroa
reproduction, Examination paper at Swedish University
of Agricultural Sciences, Summary at http://www.algonet.se/~beeman/research/cell.htm
An article on this work published in Swedish by Fries, Ingemar,
2000, Har storleken betydelse?, Bitidningen October 2000:
11-13.
8) http://www.beesource.com/pov/lusby/index.htm
9) Koeniger, N., Berg, S., Fuchs, S.,
Worobic, m., and Ullman, U., 2000.
"Russische"
Bienen aus den USA gegen Apis mellifera carnica aus
Oberursel: Varroavermehrung im Vergleich, Den tsches Bienen
Journal, Oktober 2000: 400-401.
10) Erickson, E.H., Atmowidjojo, A.H.
and Hines, L., 1999. Varroa-tolerant
honey bees are a reality, Am. Bee J. 139:931-933.
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