“Apimondia in Africa: On Becoming a Better Beekeeper”
Bee Culture (Jan thru Sep 2002), Vol. 130
By
Dr. M.T. Sanford
http://apis.shorturl.com
Introduction:
The editor’s charge: “Should
you accept this assignment Dr. Sanford, I would like your articles from Apimonda in Africa to show
readers how to become a better beekeeper.”
The theme song from “Mission Impossible” began playing in my brain
<http://www.soundingrocket.com/mi/index.shtml#music>. Then I remembered the other admonition of the
television series, “Your
mission, should you decide to accept it, is to….. This recording will
self-destruct in five seconds”
<http://www.soundingrocket.com/mi/taped_message.html>. Like the erstwhile Mr. Jim Phelps (the hero
of the original series for the uninitiated), I couldn’t pass up the
challenge. I knew it would be a big one
from the start. The African Apimondia World Apiculture Congress would be my fifth. Others I’d attended were in Acapulco,
Mexico (1981), Budapest, Hungary
(1983), Rio de Janeiro, Brazil (1989) and Vancouver, Canada
(1999). Although I had been the
recipient of a lot of information from each and they enriched my knowledge of
the craft in many ways, I wasn’t sure what specifically I had brought back that
would make me, or anyone asking me questions, a better beekeeper. This concern is not new; it has been one I’ve
had to wrestle with throughout my career.
This time it followed me all the way to the Republic of South Africa
and will be continuously with me as I write this series of columns. Thus, I found myself awakened in a sweat one
night afraid being found out and subjected to the final admonition on the the Mission Impossible tape: “ As always, should you or any
of your IM Force be caught or killed, the secretary will disavow any knowledge
of your actions.”
In the final analysis, I have
come to recognize that I really never know what bit of knowledge will make
anyone a better beekeeper. I do know,
however, that I have sat through innumerable honey bee conferences all over the
world and that about 90 percent of what I’ve heard has not been immediately
useful and a lot of it was pure drivel.
On the other hand, I have gleaned a lot from the remaining 10 percent. The major problem, however, is that in order
to realize that latter amount, one must literally sit
through the whole event. It is my
objective, therefore, that these articles will provide the readership with the
best of the ten-percent of what I came away with from first Apimondia
to be held on the Dark Continent. In the bargain, the readership will not have
to endure sitting through the actual presentations. But in order for me to have met my objective,
the readership will have to be the judge.
So it is my fervent hope that some form of acknowledgement that I have
accomplished my objective will be communicated to the secretary (editor),
keeping the Mission Impossible demons at bay.
What is Apimondia?
Part and parcel of the
conundrum I expressed above has to do with Apimondia
itself <http://www.beekeeping.com/apimondia/index_us.htm>. Somewhat like the United Nations, it is a
confederation made up of member beekeeping associations. Every two years the Association holds a
congress in a member nation. The goals
of each vary, but generally the theme for those attending is to get an
understanding of the host country’s beekeeping challenges and to hear about
current honey bee research and beekeeping experiences in that country, as well
as from around the world. Apimondia has traditionally had a European focus and met
more times in that part of the world.
The President and General Secretary are
European as are most of the chairpersons of the standing committees. The latter number seven and include apitherapy, bee biology, bee pathology, beekeeping economy,
beekeeping for rural development, beekeeping technology and equipment, and
pollination and bee flora.
Member countries in Apimondia number fifty one at present. Most dues are paid by governments of the
member countries, though there may be exceptions I am not aware of. Like its relationship with the United
Nations, where the United States has been chronically behind in its dues
payment and often not supportive of key issues, this country has a tenuous
connection with Apimondia. At the moment, the U.S. being one of the largest and
richest nations of the world with arguably one of the most recognizable
beekeeping industries and honey bee research establishments is not a
member. In the past, the Eastern
Apicultural Society and the American Beekeeping Federation shared in paying Apimondia dues, but no longer. Many in these organizations have not been
convinced that membership has contributed to the success of their members. Nevertheless, Apimondia
has unfailingly welcomed and encouraged attendance of both U.S.
researchers and beekeepers at its meetings.
Tellingly, Canada,
which hosted the last event dropped its membership after the Vancouver congress, which most agreed was the
most comprehensive and best organized ever held.
South African Beekeeping
As
customary, South African beekeeping took center stage at the International
Congress Centre (ICC) in Durban, KZN (KwaZulu-Natal) province
October 28 through November, 1 2001. According to Adriaan
Du Toit, writing in the South African Bee Journal’s special Apimondia
issue ( Vol. 71, No. 3, Septmber 2001), there are
more than 3,000 beekeepers in South Africa, with only a third belonging to
organized associations. Some 75,000
colonies are managed in the country.
Colonies produce on the average around 23 Kgs
(2.2 lbs = 1Kg) in the year 2000. The
total honey crop approaches 1,400,000 tons.
South Africa
exports from forty to sixty thousand pounds of honey each year, although this
has dropped dramatically in the last two years (6,000 in the year 2,000!). The country traditionally imports from five
hundred to seven hundred thousand pounds of honey; this also dropped
significantly in the year 2000 to 2,800 pounds.
Domestic consumption is stable at 1,700 to 2,000 tons. South African beekeeping generates some
10,000 direct jobs each year and has an indirect multiplier of 3.2 It is a
significant industry and the Apimondia event was the
largest international agricultural exposition in the country this year.
As in the Americas, Europeans have been the driving force
behind modern apiculture in South
Africa.
Most of the rest of continent has an aboriginal bee hunting
tradition. Unlike the Americas, however, the Europeans rely on the
honey bees that are native to the Dark Continent
and have generally left the European honey bees in their native land. The first apicultural census in the country
in 1911 revealed a colony average honey yield just a little over six
pounds. Yield languished at just over
twice that amount until the 1960s ended.
Since then, yield per colony has tripled, correlating to 1) results of
the first beekeeping congress held in 1968, 2) beekeepers traveling outside the
country to learn new management techniques (especially Apimondia
in Australia
in 1977) and 3) establishment of the Ministry Apicultural Advisory
Committee. The 1970s were the “golden
years” of South African beekeeping with averages of over 66 pounds per
colony.
A dramatic shift in modern
South African beekeeping came in the 1980s, when it changed focus from honey
production to commercial pollination.
More than 40 crops are dependent on managed pollination. Hybrid sunflower seed alone uses some 20,000
colonies, while 18,000 are employed in apple and pear pollination in the Cape of Good Hope region.
Honey bee pollination contributes to about 2.5 billion SA Rand (about
$250,000) to the economy, whereas bee products are only responsible for $61,000
of GDP. Beyond the first world
incarnation, South Africa
also has a third-world apicultural industry allied to that found elsewhere in
the subsahara, which has a great deal of potential.
Two huge beekeeping
challenges have appeared in South
Africa in the 1990s. The first was recognition of the so-called
cape bee problem,” and right on the heels introduction of the Varroa mite (Varroa destructor). Though not on the Apimondia
agenda, those attending the conference could not ignore the significant human
challenges that also exist in the country.
These include the transformation of society through the abolishment of Apartheid
<http://www-cs-students.stanford.edu/~cale/cs201/apartheid.hist.html> and
the effect of the HIV/AIDs epidemic, which is
ravaging most of the continent.
As a
poignant reminder of the latter, there is a memorial park with a large metalic red bow located just a block from the International
Congress Centre (ICC) where the congress was held. A
commemorative plaque states: “Gugu Dlamini was a community worker who strived tirelessly to
educate people about HIV/AIDS. She
publicly revealed her HIV positive states on radio and television, as part of a
campaign of acceptance and disclosure.
Her statement was resented and she was brutally assaulted by a mob,
resulting in her death on 14 December 1998.
This park was named on World Aids Day, 1 December 2000 to honour Gugu’s courage in breaking
the silence of her affliction.” The
controversy concerning AIDs continues to this date
with words by the current President, which many claim reveal his denial about
the current situation in the country.
The ICC is a thoroughly modern facility close to the center of the city
of Durban. The registration desk featured a public video
display welcoming participants and showing a schedule of events. It is the same venue that saw the collapse of
the International Human Rights Convention a months
earlier.
A continuing reminder of the
legacy of apartheid that produced a large “have” and “have-not” society cheek
by jowl were abundant reports of criminal activity in
the newspaper and also by some of those attending the Apimondia
meeting. One person was reported to be
robbed at knife point; another the victim of a beach ripoffs. Most hotel
patrons were cautioned not to venture out alone at night.
Change is seen in South Africa in
many other ways. This was perhaps
nowhere more apparent than in the entertainment the organizers arranged. Called “African Frenzy,” it began with a
video production showing the much varied geography and human and wildlife
population of the country. At the
conclusion, a group of black dancers burst through the paper screen in
traditional garb and began a frenetic Zulu dance. To the surprise of the audience, one of the
warriors was obviously a bare-breasted female.
It was confirmed to me later that this was just one expression of female
liberation being explored in the country, as women take on more roles
traditionally thought of as male. The
set and dances were also divided into two worlds; traditional Zulu huts in the
bush contrasted with typical plank housing of township or urban dwellers. The dances also showed both sides, ranging
from Zulu impe or warrior dances to a rhythmic
drumming of hands on rubber boots.
The Cape Bee
Problem
The Cape
bee problem was discussed under the Apimondia Bee
Biology Standing Commission.
Traditionally, two races of honey bees have co-existed in South Africa, a northern one (Apis mellifera scutellata) and a southern one (Apis mellifera capensis),
separated by a fairly wide geographic boundary consisting of large tracts of
arid climate, extensions of the Khalahari and Karoo deserts.
Both subspecies are good pollinators and honey producers in their own
regions. Capensis, however, has a trait scientists call thelytoky. This means that capensis worker bees can lay eggs
that also develop into workers, in effect cloning themselves. These so-called pseudoqueens
may be an adaptation to the winds that blow near the Cape
of Good Hope, which severely affect the mating ability of virgin
cape bee queens. By contrast, eggs of
laying workers in honey bees found everywhere else in the world more often than
not result in drones, known as arrhenotoky. It is important to realize that a small
amount of thelytoky is probably present in most races
or ecotypes of honey bees.
In the early 1990s, capensis bees
were moved as part of migratory beekeeping into scutellata areas. The result was that worker cape bees began to
enter scutellata
colonies. This precipitated in quick
order, queen supercedure by scutellata colonies, followed by
a decline in population and colony demise.
This phenomena is called “social parasitism,”
and has been responsible for tens of thousands of colony losses in scutellata
country. The social organization of scutellata
colonies appears to be pheromonally disrupted by capensis workers;
they simply self-destruct. There is no
immediate answer to the problem it seems, although research reported at Apimondia is continuing both at universities and through South Africa’s
Plant Protection Research Institute
<http://www.arc.agric.za/institutes/ppri/pprimain.htm>.
The capensis problem brings
identification of honey bees to the fore.
H.E. Hepburn and S.E. Radloff f the Apiculture Group, Rhodes University,
Grahamstown,
South Africa reported
that standard taxonomic convention in honey bee classification, the trinomial Apis mellifera (capensis, scutellata, etc.) cannot adequately accommodate
the groups they have found in the country.
“Incongruities between morphometric, biological and DNA groups preclude clearly
defined boundaries for southern African bees.
A compromise of all characters suggests the following groups: (1) thelytokous A.m.capensis; (2) thelytokous
hybrids; (3) thelytokous A.m.scutellata; (4) arrhenotokous A.m.scutellata; and 5) arrhentokous
mountain bees. “The only way that ‘A.m.capensis’ can be meaningful is to precisely qualify its
point of origin in the Cape Provinces.” The use of the term “hybrid” is unfortunate,
according to Dr. Hepburn, who said in his presentation that it was more
informative to call such bees “intermediate” instead
At first blush, the South Africa
situation may not hold much meaning for honey bees elsewhere, but the
identification issue can be applied to the present “Africanized” bee situation
in the Americas. The so-called “hybrid zone” in Argentina,
which includes both European or African subspecies or mixtures may be the same
kind of phenomenon as found between capensis and scutellata. With
reference to the “Africanized” bee in the Americas,
Dr. Hepburn said in his judgement they were simply
nasty, little bees from Pretoria
in most of their tropical range, when queried for his opinion at the
meeting. How the Africanized honey bee will play out in
temperate North America is still in question
and is one of the quintessential beekeeping conundrums that must be faced in the
future. It is of more than passing
interest that Africanized honey bees in Arizona have in fact been determined to
have a higher degree of thelytoky than their European
sisters <Di Grandi Hoffman-Erickson, Bee Science
>. This suggests a biological reason
for requeening failures sometimes reported by
beekeepers trying to introduce European stock into tropical America.
The
behavioral basis of social parasitism was discussed by Peter Neumann of Martin-Luther-Universität
Halle-Wittenberg, Institut für
Zoologie.
Beyond thelytoky, the social parasitism evoked
by capensis
pseudoqueens requres a high
ovarial and pheromonal
development, a long reproductive period (3-5 months) and the capacity to lay up
to 200 eggs per day. The development of pseudoqueens is particularly well expressed in colonies of
other honey bee subspecies (i.e. scutellata), so that they are able to develop retinue
behavior in host workers and can suppress the rearing of replacement
queens. This social parasitism is
expressed as so-called "dwindling colony" syndrome. The resulting “capensis” calamity for South
African beekeepers suggests that these invasive parasitic workers are highly
virulent.
A. m. capensis workers require several behavioral traits
related to both transmission and virulence according to Dr. Neumann.. Transmission means that these pseudoqueens must actively move to get into nearby
colonies, perhaps by drifting. However,
they also are able to find colonies up to a kilometer (.6 miles) away. Pseudoqueens must
somehow avoid guard bees. In some cases,
they may join swarms. Long range
transmission is important as the wild A.
m. scutellata host population appears to be
highly infested. The author says the
relative proportions of the different pathways actually leading to new
infestations remains unclear.
Virulence is also an important part of the equation Dr. Neumann says. Pseudoqueens appear to avoid the queen in colonies they
invade and establish dominance by getting workers to preferentially feed them
while developing their pheromonal communication
abilities. Whether workers show specific
appeasement tactics or simply rely on a fast-track pheromonal
development is not known. In addition,
eggs laid by pseudoqueens must also avoid being
“policed,” that is eaten, by other workers, the fate of most worker-laid eggs
in colonies with a high degree of arrhenotoky. To do this, they apparently lay eggs in
out-of-the-way locations and also like a regular queen, one to a cell, instead
of many to a cell as do most laying workers
Other research reported
in South
Africa shows that larvae resulting from capensis eggs are
also preferentially fed by host scutellata workers.
Eventually, high numbers of A. m. capensis workers are reared by A. m. scutellata host colonies during
later stages of infestation. This
offspring can infest new host colonies via the individual or the colonial
pathway, thereby completing the social parasitic life cycle of laying A. m. capensis workers. Although some of the behavioral traits of laying A. m. capensis workers have been described in detail, the
researchers says that the basic frame work for the social parasitic life cycle
appears to be still poorly understood.
Annelize Lubbe of
Agricultural Research Council, Plant Protection Research Institute reported on
efforts to identify pseudoqueens. Color, spermatheca
size, ovarial development all point to black workers
as capensis with a 98 percent probability. Unfortunately no single factor can be used to
make the determination. All the black
bees tested which had a large spermatheca and high ovariole counts, were shown to be genetically identical,
confirming that when workers of the capensis subspecies
reproduce parthenogenetically for several
generations, autoselection occurs directed towards a
homozygous genome – a blacker bee with a bigger spermatheca. Other studies reported at the meeting confirm
this size differential when looking at other characteristics such as wing
measurements. This state of affairs is
actually a hopeful sign, however, according to P. Kruger who said that since
the capensis
pseudoclone does not mix its genes readily with scutellata, it is still possible to find
populations of the latter in areas remote from commercial beekeeping.
A take away message from those studying the capensis problem is that it arose
from purposeful movement of colonies through migratory beekeeping and this
practice perpetuates it. One way to
control the phenomenon, therefore, is simply to stop transhumance in honey bees,
a virtual impossibility in the modern agricultural setting. Given this situation, questions remain
concerning how the capensis
situation will affect beekeeping in other parts of Africa. By extension, the rest of the world may also
be at risk as well. Theoretically, it
would take only one capensis
laying worker introduced into any honey local bee population found on this
globe to change it forever.
Varroa in South Africa
Consideration
of the Varroa situation in South Africa as well as the rest of
the world falls under the Bee Pathology Standing Commission. Treatment of Varroa
was the largest symposium in Durban
as might be expected and took two full sessions. Varroa has long been present in Africa. This author saw it on European honey bees (Apis mellifera carnica) in Egypt in the early 1990s. By all accounts most of Africa north of the Sahara has been affected since the 1980s, but it was not
reported in the south. P. Kryger first found the parasite in the Cape region of South Africa in
August, 1997. Since then, it has spread
to the border of Kruger
National Park, occupied
by scutellata
bees. S. J. Martin & P. Kryger discussed the impact of Varroa destructor so far in South Africa. Originally several factors were thought to be
important in limiting its spread. One is
that capensis
has the shortest post-capping time of any honey bee ecotype. This is considered one possible reason that
Africanized honey bees in the Americas
are more Varroa-mite tolerant. The shorter this development period, the
fewer female mites that are produced, which is why Varroa
is hardly ever found in queens (15.5 days) and prefers drones with the longest
post-capping time (about 24 days). This
fact and also that scutellata
bees in the Americas are
reported to be more tolerant in general were seen as hopeful signs that Varroa would not be as problematic in South Africa as
reported from other parts of the world.
Experiments reported at Apimondia, however,
have shown that neither of these factors appear to
affect mite reproduction. The fact that
some colonies have not collapsed with very high mite levels (tens of thousands
of mites) provides some residual optimism, but researchers believe there will
be large losses once the Varroa population becomes
entrenched and begins to spread viruses already present in the country.
Where the Varroa mite has been reported in other parts of the world,
there have been catastrophic losses of feral honey bee colonies. In Europe and the United States beekeepers do not
rely on the wild population for the health of their industry. Instead, package bees and queens are produced
to replace Varroa losses. In Southern Africa,
however, the beekeeping industry uses the wild or feral population
extensively. Many South African
beekeepers managing Langstroth hives do no nest
management at all, simply letting natural swarms populate colonies that are
lost either to swarming, absconding or activities of pests and predators. And in the central part of Africa,
there is no beekeeping per sea. Rather,
the human population relies on rustic hives (logs, clay pots) again based
strictly on feral honey bees. Loss of
the wild population due to Varroa, therefore, could
be cataclysmic for both the first- and third-world beekeeping practiced in
central and south Africa.
Taking the above under consideration, M. Alsopp
of South Africa’s
Plant Protection Research Institute discussed some of the practical aspects of
a Varroa management plan in the country. Left to their own devices African honey bees
may be able to accommodate the mite as they appear to have done with other
honey bee diseases he said. It would be
expected that large numbers of African colonies would collapse and die as a
result of Varroa, both in the wild and managed bee
populations, but thereafter, resistance to the mite is expected to develop
rapidly in these populations. Only Varroa-resistant bees would produce swarms and drones
allowing natural selection to take its course toward tolerance. The economic demand for
commercial honey bee colonies will, however, dictate that beekeepers
treat colonies with Varroacides should honeybee
losses become considerable. This appears
to be already happening.
Treatment will artificially sustain the susceptible honey bee population,
according to Mr. Alsopp, and will prevent the
development and spread of a naturally-selected Varroa
resistant population. Hence, a
comprehensive response to the Varroa threat is
required, involving Integrated Pest Management (IPM) strategies, further
research, and regional, governmental and legal strategic actions.
Included in this strategy would be:
1. The development of mechanisms or legislation for the regional control
and rotation of Varroacides with different modes of
action, to guard against the development of resistance in the mite population
and to preserve adequate chemical control.
2. The development of guidelines for the use of non-regulated chemical
products presently being used
against the Varroa mite.
3. Mechanisms to ensure the responsible use of chemical measures.
4. The development of cultural (non-chemical) control measures against Varroa, to supplement chemical control.
5. The active development of natural resistance to the Varroa mite by wild honey bees by restricting the use of
chemical control in certain regions, facilitating the development of tolerance
by natural selection.
It will be instructive for the rest of the world to closely follow the Varroa situation in south and central Africa. This situation not only has great importance
for beekeeping however. The honey bee is
a native insect in Africa and therefore its
survival and health is important for many wild plant communities that rely on
it for pollination and propagation.
Varroa Types Continue to Proliferate
It was first reported at the last Apimondia
meeting in Vancouver, Canada,
by Dr. Denis Anderson of Australia’s
Commonwealth Scientific and Industrial Research Organization (CSIRO) that there
are many more kinds of Varroa than first meet the
eye. Three distinct species were
initially identified, V. underwoodi, V. rindereri and V. Jacobsoni. The
latter was considered the most virulent and responsible for the worldwide Varroa phenomenon causing widespread destruction of
colonies of European honey bees until Dr. Anderson determined that it was not
the culprit at all through analysis of DNA.
Instead, another species, he named V.
destructor, was the cause. If that
wasn’t complicated enough, Dr. Anderson reported he had isolated 18 genotypes
in the species complex.
At the South African Apimondia meeting, Dr.
Anderson reported that over twenty genotypes of newly-named Varroa destructor and newly-defined Varroa jacobsoni now exist. A critical piece of information to come from
this work is that particular strains of Apis cerana carry their own kind of Varroa mite. It was from the Asian
honey bee (Apis cerana) that the mites on the European
honey bee (Apis mellifera)
were thought to have originated. Java
and Malaysian strains of A. cerana, for example, carry Java and Malaysian genotypes
of V. jacobsoni
respectively, while Korean and Vietnam
strains of A. cerana
carry Korean and Vietnam
genotypes of V. destructor respectively. Only two genotypes of V. destructor are responsible for the worldwide destruction of so
many European honey bee colonies. These
are the so-called Korean and Japan/Thailand genotypes of V. destructor.
According to Dr. Anderson, the Korean genotype has the widest
geographical distribution, affecting A. mellifera in the Europe, the UK,
Russia, the Mediterranean,
the Middle East, North Africa, Asia, North and South
America, Canada
and New Zealand (and now
identified in South Africa). The Japan/Thailand genotype of V. destructor has a more restricted
distribution. It affects A. mellifera in
Japan, Thailand, North and South America and Canada. In the Americas,
this mite was initially found only in Brazil,
but has since spread to other parts of South and North America and Canada. While the detection of this mite in Brazil seemed incongruous at first, it
correlates with reports that Varroa first
appeared in Brazil following
the introduction of European honey bees from Japan in the 1970s.
The ability of any genotype to effectively reproduce is one possible key
to its control, according to Dr. Anderson.
There are many possibilities.
Some genotypes on A. cerana only reproduce in drone brood,
however, they may or may not reproduce on A.
mellifera drone brood. Most likely, oogenesis
(egg-laying ability) in all these mites is activated by Juvenile Hormone III
(JH III). Recent studies in Java have
indicated that the component that Varroa mites need to activate JH III is a host
(bee) component and is obtained within a 72-hour period after the mites enter
bee brood cells. This component is
likely to be the same or very similar in all Varroa mites, as it has to eventually activate
JH III. It may differ in different bees
by being present in specific concentrations, or released in slightly modified
time frames. Finding this component may
enable the development of lines of A. mellifera that are totally resistant to the Korea and
Japan/Thailand genotypes of V. destructor.
The above analysis may help explain some of the tolerance that A. mellifera is
now showing to V. destructor in
different parts of the world, according to Dr. Anderson. Indeed, breeding programs currently underway,
such as those developing SMR honey bees or attempting to use tolerant bees
identified from other parts of he world, may actually be exploiting this
mechanism, he concluded.
Varroa and Viruses
The
existence of large Varroa parasite populations in
colonies of honey bees that appear to be healthy prompts the question of how
specifically the mites are affecting their hosts. There is a parasite component, but it also
important to understand that a viral one exists as well. N. L. Carreck and
associates of the Plant & Invertebrate
Ecology Division, IACR-Rothamsted, Harpenden, Hertfordshire reported
on the correlation of Varroa infestation with various
viruses in the United
Kingdom.
Investigations in Devon
and Hertfordshire from 1992 to 1996 determined that the death of severely
infested colonies was associated with slow paralysis virus (SPV); an infection
which had never previously been found to be responsible for mortality in
nature. The authors say the occurrence
of SPV in dead adult bees and brood seems to be parallel to that of acute
paralysis virus or APV in infested colonies on the European mainland, although
APV too has rarely been found as a cause of mortality in infested colonies in Britain. Both viruses normally persist as latent infections
in bees, are infective by injection into the haemolymph,
are rapidly fatal, and are transmitted to both brood and adult bees by the
mite. The authors found two other
viruses in Varroa-infested colonies, cloudy wing
virus (CWV) and deformed wing virus (DWV.
A number of additional viruses, filamentous virus (FV), black queen-cell
virus (BQCV), bee virus Y (BVY) and bee virus X (BVX), were also detected in
dead adult bees from Varroa-infested colonies, but
were not considered vectored by mites.
The authors say that DWV has now become the most widespread infection in
association with V. destructor in
honey bee colonies in Britain. It was known previously only as an infection
of adult bees, but the mite has been found to be responsible for introducing
the virus into a life stage of the bee that it would not normally infect. Unlike APV and SPV, DWV is not rapidly
fatal. Bees infected at the pupal stage continue to develop and emerge, although all
contain large amounts of virus and their longevity is significantly
reduced. Large amounts of virus also
accumulate in bees infected after emergence but their lives are not similarly
shortened. These provide a persistent
reservoir of infection for mites to acquire and transmit, which explains the
eventual predominance of this infection.
The presence of viruses linked to mite parasitism puts a more complex
face on the Varroa control situation. Many integrated pest management (IPM)
techniques seek to reduce the mite population,
however, these would appear to be less effective if viruses rather than mite
numbers were found to be the major contributors to honey bee colony loss
associated with Varroa.
Unfortunately, viruses are not well understood and research effort on
them is minimal. Thus, there continues to
be a large research effort around the world that seeks to reduce mite
populations in bee colonies in the hope that losses will as a result also be
minimized. The South African Apimondia symposia featured studies using chemicals such coumaphos, oxalic acid, thymol to
control Varroa.
In addition, other techniques were described, including powdered sugar,
drone traps, queen confinement, and Dr. Zachary Wang’s Mitezapper
<http://www.mitezapper.com>. The
latter has been described in previous articles in this magazine.
Integrated Pest Management (IPM) and Varroa
Perhaps most intriguing was K. Fakhimzadeh’s
study using powdered sugar as a control measure. Evidence in the United States
shows that powdered sugar is a reasonable way to show relative mite infestation
levels. This technique developed
at the University of Nebraska, however, has not been considered effective as a
control in the nest, especially when brood was present, since mites ensconced
in brood cells were not vulnerable <http://entomology.unl.edu/beekpg/tidings/btid2000/btdjan00.htm#Article2>. Dr. Fakhimzadeh’s
study showed a mite knock down with powdered sugar of 91% with direct dusting
and 62% with air- assisted dusting.
Sugar dusting efficiency in knocking down the Varroa in some cases was similar to that reported for mite kill in
studies using chemical applications. The
study also compared the technique to using carbon dioxide (CO2) in
conjunction with powdered sugar. It was
shown that CO2 in combination with sugar or alone did not increase
the mite fall so the author recommended not using it as part the control of V. destructor.
Mr. Fakhimzadeh’s results reconfim
that powdered sugar treatment as described does not have any obvious side effect on
the capped brood nor the growth of the bee population. In addition, no
queen loss occurred even if the treatment was applied as frequently as every
three days for a period of one month. It
was concluded that sugar dusting alone is a useful tool, which could be
included in integrated mite management programs. Though not reported in his paper Mr. Fakhimzadeh said in his presentation that particle size is
important, and small particles of five microns was
optimal. Most icing sugar is a mixture
of particle sizes, thus, its present configuration (as found in most stores) is
variable and this would presumably affect mite control efficiency. Again, since mites sealed in brood cells are
affected, several applications would be necessary to ensure good control.
Dr. Joerg Schmidt-Bailey, University of Illinois, Urbana Champaigne, IL
<http://www.urbanext.uiuc.edu/staff/schmidt.html> discussed a series of
Integrated Pest Management (IPM) techniques based on trapping mites in drone
brood. As he put it,
“from humble beginnings to patented devices.” Originally, worker brood was used to trap
mites; later that of drones (taking advantage of the fact that a longer
post-capping time produces more mites) was substituted. Finally, the use of the Mitezapper
was described as another advancement. Dr. Schmidt-Bailey concluded that he expects
to see more developments in this arena in the future. Conspicuous by its absence was an IPM
technique that has been getting recent attention in the U.S, the use of the
open-meshed floor.
G. A. Piccirillo & D. De Jong reprsenting
the Departamento.de Biologia,
Fac. Filosofia Ciências e Letras de Ribeirão Preto - USP, SP Brazil
studied the Varroa infestation rate in different
types of worker cells in eight africanized honey bee
colonies. New brood combs (NC) built
naturally by the africanized honey bees and old brood
combs (OC) with relatively smaller cells were placed in the same colony and
with egg laying by the same queen. The
results showed that OC cells attracted more Varroa in
relation to NC cells, even though the cells had a smaller diameter. They concluded that though cell size may be
important, characteristics inherent to the larvae, to the comb or the food in
the OC workers cells might have an important influence in attracting Varroa. This study
provides some more evidence that periodic renovation of brood combs, also
considered to be important in reducing microorganism numbers (those causing
foulbrood and chalkbrood as examples) in a colony
could also reduce Varroa populations in the bargain.
Varroa
Research in Argentina and Brazil
The
largest contingent of displays at Apimondia’s
apiculture exposition in South Africa
was from Argentina. I was told over 40 persons registered from
that country. One reason was the
extensive lobbying the group did to become the site for the 2005 event. Unfortunately, their bid was not accepted,
going to Ireland
instead. Nevertheless, it is abundantly
clear that Argentina
is emerging as one the premier world apicultural powerhouses.
It has
been clear for some time that tropical Brazil appears to weathering the Varroa mite storm with little if any chemical treatment by beekeepers on Africanized honey bees. In contrast, there is much interest in
controlling the mites in Argentina
where many European honey bees exist using a variety of possible
solutions. Several presentations at the
South African Apimondia meeting revealed that these
two countries are collaborating in this research. Examples included comparing queens with
identical genotypes in both temperate and tropical parts of Argentina. One paper concluded that climate does play an
important role in mite reproduction; most mite reproduction was found in
temperate areas. A comparision
between non-hygienic (NH) and hygienic (H) stocks revealed that differences in uncapping and removal between hygienic and
non-hygienic colonies were significant.
One hour after killing of the worker brood by pins in the H colonies
about 45 % of the brood was completely uncapped but only 4 % in NH colonies. However, 100% of the brood was totally
uncapped and 43% removed by H colonies after only four hours; it took the NH
component 24 hours. Thus, it is possible
to discriminate between H and NH colonies in only one hour using observation
hives. Hygienic behavior consisting of
both uncapping and removing dead brood (HR) as well as brood infested by Varroa (RR) was also investigated. Differences were observed in commercial
colonies deemed susceptible to mites and feral colonies that were
tolerant. However, the authors concluded
that the results do not fully explain mite tolerance by some colonies in South America.
Brazilian beekeepers have for a time now been making assertions that
because no treatment for either Varroa or brood
diseases was necessary, the honey coming from their country should qualify as
“organic.” Argentina also appears to be
climbing on this band wagon in a somewhat different way. Investigators, thus, are looking at a
specific formulation of formic acid in a gel matrix (Beevar). They conclude the product is a good alternative
for Varroa control because it is organic, effective, easy to use and does not affect queens, workers or brood in
treated colonies. A formulation of 4.5
percent oxalic acid (Oxvar) is also under
investigation. Both products are
considered effective against mites, however, the latter one is more compromised
when brood is present. Another
innovative project involves incorporating organic products into foundation in
the hope of producing a comb that is in effect its own treatment device. Seven treatments were used including several
concentrations of formic acid, oxalic acid and thymol. In general, comb with these products
incorporated had fewer mites per cell than normal (control) foundation.
Other Argentine research reported on laboratory studies using essential
oils to control Varroa. According to the authors, about 150 different
essential oils have now been tested as an alternative to synthetic acaricides. These
are especially prepared in emulsion and applied using a “Burgeon tower.” Varroa killing
ability is determined at 3, 4 and 5 percent concentrations. The oils of two specific plants, Heterotheca latifolia and
Tagetes minuta reported
here showed 63 and 56 percent lethality at 5 percent concentration respecively.
Although the results are encouraging, the authors say that translating
laboratory results into effective field trials will still require a good deal
of study and effort.
The
strong Argentinian presence at the South African Apimondia was apparent to even the most casual
visitor. The country barely failed to
win approval to host the 2005 meeting, but no doubt will be a strong candidate
for the 2007 event. There is little
doubt that Argentina
will continue to be a powerhouse in apiculture for a long time to come in spite
of the uncertain economic conditions the country now faces.
No formal agricultural extension service exists in Argentina as does in the United States. In fact, a clear disassociation exists
between the formal educational sector (university) and small-scale producers. A recent collaboration, however, between
university researchers at La Facultad de Ciencias
Veterinarias de la Universidad Nacional
del Centro (UNCPBA)and others such as the Facultad de Ciencias Agrarias y Facultad de Ciencias Exactas y Naturales de
la Universidad Nacional de Mar del Plata, as well as
the ministry of social development has resulted in what is called the
Integrated Apicultural Development Project or PROAPI as showcased in South
Africa. This is described as an extension
network that is particularly necessary at this time, given the fact that small
honey producers are considered an important aspect of the development process
in Argentina. Paralleling to an extent the Cooperative
Extension Service model in the U.S.,
the network formally recognizes the role of universities and places them in the
context of doing research as well as training beekeepers.
Rather
like the Master Beekeeper programs in some states, the program has a “train the
trainer” approach, where students agree to return to their home base and teach
what they’ve learned. There are two
levels. The second one is composed of
two years of university education. Much
of the program is based on electronic communication via ApiNetLA
(formerly APINET) on the World Wide Web <http://www.inta.gov.ar/apinet/la/index.htm>. I reviewed this site in my Bee Culture Digital Age Column in May
2000 <http://bee.airoot.com/beeculture/digital/2000/column21.htm>. Unfortunately, many of the links published in
that article have been modified. But the
home page still directs the user to applicable sections and is a more robust
arrangement of its former self, although still clearly under construction. This is the first integrated knowledge center
on apiculture in any Latin American country to my knowledge. Currently it has links to beekeeping in
México and the Dominican Republic,
as well as Argentina
and Perú, in fact metamorphosing into a Latin
American apicultural portal. As a
consequence, the Web site now refers to itself as ApiNetLA. I reviewed the concept of portals in my
Digital Age column <http://bee.airoot.com/beeculture/digital/2000/column19.htm>.
Other aspects of the ApiNetLA site include a discussion of Abejas
del Tucumán.
This name is shown as a registered trademark. According to the site, the honey bees of
Tucumán take advantage of exceptional ecological conditions found in Chaqueño park. The beekeepers in this association are also
assisted by several governmental agencies to ensure their products adhere to
strict quality control standards.
Research
is integral to Argentinian beekeeping and was
certainly in evidence at the South African Apimondia
meeting, and is also implemented on the ApiNetLA Web
site. Already described in this series
of reports on the South African event is that concerning Varroa
in Argentina. However, that is
just the tip of the iceberg. Papers at
the meeting discussed topics in almost all of the standing commissions from
content of flavinoids in Argentinian
propolis (apitherapy) to mead making
(Beekeeping Technology and Equipment).
The honey bee behavioral research focused on defensive and hygienic
behavior. One paper by C. Andere and colleagues contrasted both behaviors in the same
population using the standard black ball attractant (defensive behavior) and
pin-killed larvae (hygienic behavior).
The results showed that both behaviors could be adequately measured in Argentinian populations, but there seemed to be no
association between the two. Thus,
selecting for one appears to be independent from selecting for the other.
Another
paper by C. Andere and colleagues compared both a
laboratory and field method for determining defensive behavior. The former used oxygen consumption and the
latter a combination of alarm pheromone (isopentyl
acetate) and an agitated
five centimeter in diameter dark leather ball. Bees from both the Africanized population
(Tucuman Province-subtropical) and European population (Tandil
Province-temperate) were compared. They
differed from each other morphometrically (the
standard way to separate ecotypes or races, but not always reliable as noted in
part one for the “Capensis:” problem). But the study showed it was not possible to
use defensive behavior to distinguish the two types because of extreme
variability shown on a daily basis. In
general though, subtropical bees were “souped” up
(used more oxygen) and faster to sting.
The results indicated it was possible to use either field or laboratory
methods in breeding programs to select for defensive behavior
A
companion paper by M. Palacio and E. Bedascarrasbure
discussed a four-year study comparing hygienic behavior, the ability of honey
bees to uncap and remove diseased/parasitized larvae. Investigators showed that this could be
improved to about 80 percent in stocks from a general background level of about
66 percent using open mating. Thus,
instrumental insemination was not important unless a degree of control greater
than 80 percent was desired. These
traits are the result of recessive genes and thus a degree of inbreeding is
needed for greater expression in a bee population . The improvement in the study was considered
enough to warrant selection programs using pin-killed brood. The investigation reconfirmed that a general
increase in hygienic behavior correlated with a decrease in the incidence of
brood diseases.
Both
defensive and hygienic behavior are now considered the
two most important traits selected for in a coordinated Argentinean honey bee
improvement program, which was reported on at the South African Apimondia. This
began in 1995 under PROAPI (see discussion above). According to the authors of a paper reporting
on this development,, among whom is E. Bedascarrasbure,
director of PROAPI, and several academics, including Dr. M. Del Hoyo, honey bee projects generally produce genetic
information (heritability), developed at universities or specialized
laboratories, but usually are not designed to select and distribute stock. The Argentinean stock improvement program (MeGA) attempts to do both.
It has several components, including colony evaluation in the field, a
program center, which contains the data bases used to make genetic decisions
(1135 colonies from eleven regional centers have been evaluated) and even a
portable instrumental insemination laboratory that can be taken to the apiary
and used on site. The MeGA program is prominently featured on the ApiNetLA Web site described above. In addition, there is a general discussion of
selection principles. Included are
descriptions of how sex alleles play into honey bee breeding and the basics of
instrumental insemination. To my
knowledge, this is one of the few integrated breeding programs in modern
beekeeping. It might serve as a model
for others and certainly deserves further study.
Africanized
Honey Bees
This author was surprised at the lack of information
on Africanized bees from much of Latin America, with only Venezuela, Uruguay,
Brazil and Argentina
contributing at the South African Apimondia
meeting. This is in great contrast to
former congresses where often research on this bee was a major topic. Perhaps this means that the situation is
indeed now maturing in most of the area invaded by the bees over the last forty
years. There was also little
contribution from North America, the last
frontier of the Africanized honey bee.
The
Africanized honey bee problem in the Americas,
of course, began in South Africa,
when the celebrated geneticist Dr. W. Kerr introduced Apis
mellifera scutellata
from that country into Brazil. Four decades later the difficulties and
successes of this controversial insect have come home to roost in the world’s
first-ever Apimondia conference in its homeland. The most complicated situation appears to
have developed in Argentina. According to E. Bedascarrasbure
and B. Marina, several local ecotypes or races have developed out of a
combination of both Africanized and European honey bees. The situation is further complicated by a
large introduction of
European queens (mostly Apis mellifera ligustica) from Buenos Aires province into the northeast and northwest
where Africanized honey bees that migrated from Brazil are prevalent. Further study, the authors say, indicates
that morphometrically Africanized honey bees are
different in much of Argentina
than in Brazil. This could explain the fact that many bees in
Argentina and Urguay despite increased defensive behavior, are
susceptible to Varroa, which does not appear to be
the case in Brazil. In spite of problems associated with
Africanized honey bees, the authors state that colony honey production is now
highest in provinces (Entre Ríos and Tucumán) where
the Africanized honey bee predominates.
In addition, in studies of sunflower pollination, it has been shown that
Africanized honey bees collect more hybrid sunflower pollen than their European
cousins.
An
update on the Africanized honey bee situation in Venezuela was provided by A. Manrique and G. Piccirillo. This
country, perhaps more than any other, was hit hard by these insects. Honey bee olony
numbers dropped from 94,000 in 1975 to 25,000 in the year 2000. Honey production declined from 600 metric
tons per year to a low of 75 in 1981, and recovering to 480 tons in 1992. Unfortunately, Varroa
took a further toll on beekeepers at that time, but the industry is again
rebounding. From 1996 to 1999 production
increased by some 28 percent, topping out at 410 metric tons. Domestic consumption of honey remains low and
hobby beekeeping has literally disappeared.
There remain many challenges to beekeeping in Venezuela, but as knowledge about
the behavior of the bees increases, the authors
believe there is an optimistic future in the country for this activity.
A comprehensive review of the
impact of the Africanized honey bee in Venezuela was provided by R. Thimann. He compiled
a bibliography of published documents from various sources, including newspaper
reports and proceedings from meetings and congresses held during the
twenty-five year history of the bee’s invasion.
Unfortunately, the author concludes that there have not been many
substantive changes implemented since 1987, when the newspaper La Nación published
a list of constraints that have kept the Venezuelan Beekeeping Industry from
developing to its full potential. These
included suggestions made as far back as 1976 such as aggressively training
beekeepers in managing the new bee, providing credit when needed, developing
projects in actively promoting and selling honey, creating a bee breeding
center and mounting a public health program based on averting potential bee
attacks.
R. Thiman and A. Manrique described observations when comparing queens from Venezuela and Brazil. The latter were instrumentally inseminated
and developed from an organized selection program. Brazilian-selected queens produced more honey
than did locally selected stock in Venezuela proper. The authors conclude that a breeding program
in Venezuela
might substantially increase productivity of beekeepers in that country.
As has been a theme over several
years, investigators from Brazil
continue to state that Africanized honey bees in their country have been a
blessing in disguise. This is especially
true with reference to their disease resistance. K. Gramacho
reported that tolerance to Varroa continues in Brazil and no
chemical treatments are applied.
Nevertheless, disease problems do arise.
There appears to be greater incidences of nosema
and European foul brood in the country’s northeast, presumably due to
“inefficient mangement” and/or excessively damp
conditions. An outbreak of Chalkbrood has been reported in the south, but has cleared
up and may have been caused by susceptible bees. Several viruses have also been detected,
including APV (Acute Paralisis
Virus), BQCV (Black Queen Cell Virus), FV (FilamentousVirus)
and QWV (Cloudy Wing Virus).
The most concerning situation in
Brazil is that surrounding
American foulbrood, which is reported in nearby Argentina. According to Ms. Gramacho, “Considering
the almost generalized distribution of AFB in all the continents, the Brazilian
beekeeping and especially, that of Rio Grande do Sul (South
of Brazil), enjoys a singular situation due the fact that it is a frontier
‘Foulbrood Area’, we can say: danger area.”
To keep this disease at bay Brazilians have relied on both legislative
and genetic controls. The former will
hopefully keep the disease out of the country altogether. The latter, however, is regarded as an ace in
the hole, and given that Africanized bees are more tolerant to almost every
beekeeping malady due to hygienic and other behaviors. Brazilian scientists and
beekeepers, therefore, are now fully endorsing breeding programs that select
for hygienic behavior.
Swarm Traps and Africanized Bees
A major tool in managing Africanized honey bees has
been the swarm trap, baited with Nassanov
(orientation) pheromone (smells like citrus and geraniums). In the only presentation on these insects
from the U.S.,
Dr. J. Schmidt of the Tucson Bee Research Laboratory presented a historical
analysis of the development of the trap.
He reported that Steve Thoenes, a beekeeper
and bee researcher who helped develop the concept,
realized in the 1990s that the time was right to develop a preventive control
system. So in 1994 he established BeeMaster, Inc., a company that specialized in deploying
perimeter swarm traps around sensitive areas in urban areas of southern Arizona. The company was
immediately successful, Dr. Schmidt said, and it deployed thousands of traps
around local enterprises, captured several thousand swarms per year, and
expanded to include the large metropolitan areas of Phoenix,
Las Vegas, and Southern
California. The traps were so successful in luring bee swarms to
enter traps instead of natural or man made cavities, that BeeMaster,
Inc. virtually never had to remove swarms not in a trap from a protected area.
Not a single stinging event from a colony not in a trap has occurred in an area
protected by swarm traps. One stinging event did occur in California from bees emanating from a trap
that, through negligence, had been allowed to remain in place so long that it
actually fell to the ground. This failure illustrates how human factors are
crucial to any control operation and equipment alone can never be totally
successful. Thus, Dr. Schmidt
concluded, knowledge from pheromones and its application has benefited
beekeeping, and by extension the general public.
These bee traps are a tried and true example of the
research that governmental (ARS) research laboratories can provide to the
beekeeping industry. The concept based
on this trapping technology has gone on to become a suitable idea for
franchising. Dr. Steven Thoenes, owner and founder of BeeMaster,
Inc., is now offering qualified investors the unique opportunity to build a
successful honey bee protection and removal business of their own. Only a
limited number of these agreements are available. They include a training
program on bee removal techniques using swarm-trap technology and a guaranteed
supply of specialized materials and products.
Information is available electronically (http://www.beetraps.com) on the franchising
opportunity along with a list of current clients and materials provided.
Small Hive Beetle:
Besides the Africanized honey bee, another exotic
insect introduced from South Africa
to the Americas
is the small hive beetle (Aethina tumida). Several papers dealt with the biology and
control of this pest, some of the first studies to have occurred in South
African since Dr. Lundie’s landmark paper in the
1940s. P. Elzen and colleagues reported that western
honey bees (from the state of Florida)
were not observed to be as aggressive in attacking small hive beetle adults as
were African bees (Apis mellifera
capensis from Gramstown). Significantly African bees also attacked
stationary pins, which were used as controls in the experiment. The authors concluded: “Such comparative lack
of aggression of Western honey bees and demonstrated higher aggression of
African honey bees may explain the economic status of the small hive beetle in
its native and introduced ranges.”
According to the authors, beekeepers in the U.S.
report that they rarely see managed honey bees aggressively defending the
colony against beetle attack, whereas beekeepers in South Africa commonly
observe managed Cape honey bees attacking and isolating small hive beetles when
they occur in bee colonies. They underscore, however, that the small hive
beetle can cause economic damage in South Africa to honey frames
removed from colonies and stored for later extraction, particularly if any
brood is present in frames. Thus, they
conclude that behavior of the adult bees within the hive play a significant
role in protecting brood and colony products, which is not the case when frames
are removed from the colony and thus without protection.
Besides aggression, another study by J. Ellis and
colleagues provided evidence in African bees of other behaviors affecting small
hive beetle. They say that African honey
bees are unique because they actually construct prisons of wax and propolis (plant resins) in their hives and then kraal (the
African term for “corral”) the beetles into them. The entrances of these
“beetle prisons” are assiduously guarded by worker bees, preventing them from
gaining access to the contents of the honey bee nest, which would allow them to
reproduce. Despite lack of access to food in the combs, imprisoned beetles may
survive for two months or so; but this is not due to stored metabolic reserves
because beetles entirely deprived of food die within a week. Thus, the honeybees themselves become suspect
of a kind of "beetle husbandry."
The authors fed cape honey bees a red dye to see if this was in fact
occurring. The dye was found in the
beetles, providing good evidence that the beetles were fed during confinement.
A study by J. Ellis and associates compared diets of
small hive beetle (SHB). “ SHB offspring were found on
honey/pollen, pollen, bee brood, fresh kaai apples,
rotten kaai apples, and honey alone, but not on wax,
or in control treatments (no food at all). The highest reproductive success was
found on pollen-fed adults and larvae, suggesting that SHB reproduction in
hives of recently absconded colonies might be very successful in nature. The
diet of honeybee brood also yielded high reproductive success for SHB. They conclude: “Our data further suggests
that SHB are capable of reproducing on fruits alone, indicating 1) that SHB are
facultative parasites and 2) that one potential pathway of SHB to the US might have been commercial transport of
fruits from southern Africa to ports in the U.S.” The fact that some beetle reproduction can
take place on fruits alone is surprising and disconcerting and certainly worth
more study..
M. Hood provided a comprehensive history of small hive
beetle in the United States. It is not known the exact entry point of this
insect, but the southeast is a prime candidate.
DNA study shows two haplotypes of beetle, one
mostly in South Carolina, the other prevalent
in Georgia, Florida and North
Carolina. Both
types were found in the same apiaries in both Florida and Georgia and they appear to be
very similar. There are, however, twelve
haplotypes in Africa so that further introduction of
beetles from Africa can be pinpointed with
better accuracy.
The beetle has now spread to
many states and is continuing to become a normal part of the U. S. beekeeping scene. Fortunately, according to Dr. Hood, there are
controls in place including both GardstarÒ (40 percent permethrin soil
treatment) and CheckMite+ (10% coumaphos
plastic strip for inside colonies).
Other approaches are needed, however, as part of an integrated pest
management effort that will serve beekeepers well in the future. This currently involves research in the use
of hygienic stock and/or pheromone-baited traps.
So far, the small hive beetle has only been found
outside its African homeland in North America. Over time, given the history of other
introduced pests on honey bees, this insect will probably show up in other
countries in the Americas. Thus, there was extreme interest at the South
African Apimondia event surrounding a film that was
produced on this insect pest and shown at the event. There was considerable controversy generated
as the production appeared to overemphasize the sensationalistic aspects of the
beetle’s invasion into North America, in one
place characterizing it the most important world beekeeping pest.
Pot Pourri of Bee Biology:
As might be expected the Standing Commission for Bee
Biology had the majority of papers at the South African Apimondia
congress. This included major sessions
on both the cape bee problem and Africanized honey bees described in earlier
reports. In addition, there was a wide
range of papers on other topics.
Z. Stanimirovic and
colleagues presented results of a study examining the variability of hygienic behavior
in two eco-geographically different populations of Apis
mellifera carnica in Serbia, Yugoslavia. Some may remember that the first bees
imported into the U.S. that
were considered to be Varroa tolerant were Carniolans from Yugoslavia,
now Serbia,
and called by many “Yugo” bees. They did not do well according to most
reports, and efforts were soon diverted to “Russian” bees, which are now being
studied extensively. These Serbian
investigators, nevertheless, saw great variability in populations of both
yellow bees from Machva and grey bees from Rudnikand, some being considered “superhygienic” . Thus, they
concluded, “The superhygienic potent honey bee
colonies (regardless queen age) at nine-investigated localities in Machva region and at ten-investigated localities in Rudnik region could be used as breeding colonies for
rearing of quality queens.”
K. Gramacho and L. Gonçalves presented information suggesting a new hypothesis
for the origin of hygienic behavior based on sequences they observed, including
puncturing the capping, removing the capping and removing the cell
contents. Instead of two recessive genes
(u=uncapping and r=removing) as proposed by Dr. Walter Rothenbuhler
in his landmark studies on this behavior, the authors believe there are three
(u1, u2 and r). Thus, they conclude, “In
order to uncap the cell, the bee should have both u1 and u2 genes as homozygous
(u1/u1, u2/u2). Only one u1 or u2 gene
as homozygous would determine the puncturing (u1/u1, u2/+ or u1/+,u2/u2) and the three genes as homozygous would be
responsible for the uncapping and removal (u1/u1, u2/u2, r/r). The authors
conjecture that such a new hypothesis needs to be more rigorously confirmed
before being adopted.
A. Langowska and associates
of the Agricultural University of Poznañ in Poland
investigated the effect of drone presence on colony nutrition. They carried out
experiments to find out the effect of the presence of drones the quality of worker bees,
including survival ability, size of pharyngeal glands and fat body, and the
content of total protein and crude fat in the body of worker bees. They conclude: “The comparatively small
consumption of food by worker bees kept with drones indicates that in the
presence of male bees, the organism of workers works more effectively, i.e. it
utilizes in a better way the components contained in food. It must be stressed
that next to the high survival rate in the worker bees consuming carbohydrate
food, there occurred also a better development of the pharyngeal glands where protein
is particularly necessary. The presence of drones had also a positive effect on
the content of total protein and crude
fat in the bodies of worker bees consuming sugar
candy.” This study may change the minds
of some beekeepers concerning the value of drones in a colony; their removal
may not be as benign as once thought.
M. Lodesani and colleagues
at the Istituto Nazionale di Apicoltura, Bologna, Italy
investigated the effects of natural mating (NM) versus instrumental
insemination (IIS) on two-year-old queens.
The relationship between queen weight and ovariole
number and between residual sperms and ovariole
number was found to be significant only in IIS queens. The authors conclude, “The latter correlation
could be due to greater uniformity of IIS queens ovaries and to a probable
relationship between spermatheca dimension and ovary
development, because in IIS queens the quantity of sperm contained in the spermatheca depends on its dimensions considering that the
injected amount was constant (8 ml). The ovarioles were counted in both groups and though there was
no difference in their number, they appeared more uniform with a more uniform
reproductive activity in IIS queens. This ‘mature’ stabilisation
of the ovary is associated with an increase in the ratio between ovary weight
and total queen weight and is reached earlier in IIS than in NM queens, showing
that IIS queens are subject to premature ageing.”
The results, according to the authors, highlight the
absence of influence of the instrumental insemination method and the subsequent
anaesthesia, on weight increase. There also appears to be few differences in
the other categories studied suggesting no inherent liability found in
instrumentally inseminated queens. The
authors believe these studies will lead in the future to an in vivo assessment
of queen bees.
Other studies included in the bee biology commission are
those reported by G. Sabatini and M. Lodesani on
continued used of honey bees as environmental monitors in Italy
<http://www.lacarlina.com/locandina/locandina.htm>. This three-year research project is a first
for Italy,
although the country has been a leader in this kind of monitoring. The project also includes other areas of
apiculture (honey and honey bee conservation biology).
Another by V. Garnery and
associates has to do with characterizing a rather large population of the
Egyptian honey bee (Apis mellifera lamarckii). “The purpose of this study was to evaluate microsatellite and mitochondrial DNA variability in a
population of A. m. lamarckii from Assiut governorate. This research derives from a larger
project to select and breed native honey bees suitable for commercial
beekeeping in Egypt. There is some evidence that these original
honey bees of Egypt
might be more tolerant than the A. m. carnica
in general use by beekeepers around the country.
Alternative Views of Honey Bee Biology
:
Apimondia has always been somewhat of a conundrum I think not
only for scientists, but also for beekeepers that attend. This is due to the juxtaposition of both the
practical and theoretical. It tends,
therefore, to bring out what some might call “fringe elements.” I recall one presentation by a participant in
Hungary
whose scientific hypothesis was that wearing bee beards was something that
every beekeeper should do to promote the craft.
It was punctuated with many slides (the speaker went way over his time)
showing the act of putting on the bees and taking them off. At that time I wondered why the organizers
put him on and how they determined this topic was something of importance to
world beekeeping. I have subsequently
learned that one of the charms of these congresses is that they do bring out a
great diversity of opinion.
Thus, at the South African congress, two papers by S.
De León of Uruguay
were presented on how biologists should revamp their study of genetics, calling
it instead something he has derived from the Greek language, “arjetics.” He
concludes, “…on the investigation made by differents
scientists the author draws biological conclusions that lead to think that bees
are sexless and each one has an own and distinguishable origin. Then he makes a
distinction between fertility and fecundity which clarifies the application of
the terminology,”
In a companion paper, Mr. De León discusses drones,
concluding that “the author presents a different vision to the classical
appreciation which defined the drones. While literature maintained that bees
belong to a genetical species, they said that the drones is a haploid bee. After several consideration
the drone is defined as a disjunction of the diploid organism. And therefore is
not the son of his mother as used to be said, but a derivative and for this
reasons is not generated, which is not comparable to a genetical
queen impeded to produce organisms whit one half of the mother’s cells.”
More understandable perhaps was the presentation by
Dr. Zbigniew Lipiński
of Poland. In his paper, “Adaptation and Stress –
Main Cause of Nest Abandonment by
Honeybee Swarms,” he says in part,
“According to Aristotle (384-322 B.C.), the leading naturalist of ancient
times, the reason for swarming was an excess of queens in a honey bee colony ‘a
plurality of chiefs brings a fission of a swarm into two parts’. This concept
probably originated from observations that the natural swarming of bees is
always preceded by the rearing of new queens. In spite of the fact that this
first hypothesis of natural swarming has never been fully scientifically
proven, it still remains a basic theoretical foundation in discussions of the
nature of swarming in honey bees. A literal interpretation of this hypothesis
(in spite of its correctness to some degree) seems to be one of the major
reasons for the lack of clear progress in understanding of, not only the nature
(essence and mechanism) of swarming, but also all other forms of nest
abandonment by honeybees. The current situation is such, that no single theory
adequately explains all aspects of this subject.”
Dr. Lipiński has
written a book on this subject entitled The Essence and Mechanism of
Nest Abandonment by Honeybee Swarms.
It was entered in the competition of beekeeping resources in Apimondia and won a prize.
In his abstract, Dr. Lipiński says, “A
better understanding of these processes can open new possibilities for control
of all forms of nest abandonment by honeybees.”
There is a difference between these approaches. Dr. Lipińskis’
is richly referenced and represents a good review of published literature. That by Mr. León, however, contains no
references. Indeed, the author claims to
have come up with the term arjetics and first
published on it in the Argentine beekeeping journal, Espacio
Apícola <http://www.apicultura.com.ar/apis_40.htm#arjetica>. That article is the only reference to this
term I could find on the World Wide Web.
Nevertheless, both presentations beg the question: on what basis was it
determined that both these papers should be accepted for the South African
congress?
Tracheal Mites:
Drs. S . Sumner and W. Mangum of Mary
Washington College, USA discussed their mathematical model, developed
based on worker bee grooming behavior. The model is age-structured and based on bees less
than one-week-old that form the susceptible group. The authors state that without autogrooming bees, the model predicts the number of
infected bees will rise. However, with autogrooming bees and all other parameters remaining the
same, the model shows the number of infected bees will approach zero over time.
With such models, they conclude, the number of autogrooming
can be varied to show how many bees might be necessary to protect the colony
from an increase in the number of infected bees.