An introduction to understanding
honeybees, their origins, evolution and diversity
by Ashleigh Milner
Bees of all kinds belong to the order
of insects known as Hymenoptera, literally "membrane
wings". This order, comprising some 100,000 species, also
includes wasps, ants, ichneumons and sawflies. Of the 25,000 or
more described species of bees (more are recognised every year)
the majority are solitary bees most of which lay their eggs in
tunnels, which they excavate themselves. In some species small
numbers of females may share a single tunnel system, and in other
cases there may be a semi/social organisation involving a
hierarchical order among the females, These bees provide a supply
of food (honey and pollen) for the larvae, but there is no
progressive feeding of the larvae by the adult bees.
Honeybees belong to the family of social
bees which includes bumble bees and the tropical stingless bees
of the genus Meliponinae. The social bees nest in colonies headed
by a single fertile female, the queen, which is generally the
only egg layer in the colony. Foraging for nectar and other tasks
such as feeding the queen and the larvae, cleaning brood cells
and removing debris, are carried out by a caste of females, the
Workers. Honey and pollen is stored, and larvae are reared in
cells made from wax secreted by the worker bees.
Typical colonies may amount to no more than
a few dozen insects, and may be annual as in the case of bumble
bee colonies, or they may number several tens of thousands and
persist for a number of years, as in the case of honeybees and
species of Meliponinae.
The sub-family Apinae or honeybees,
comprises a single genus, Apis, which is characterised by the
building of vertical combs of hexagonal cells constructed
bilaterally from a midrib, using only the wax secreted by the
worker bees. The cells are multifunctional, being used repeatedly
for rearing the larvae and for the storage of honey and pollen.
Progressive feeding of the larvae is carried out by young bees
with food produced by glands in the head of the bee from honey
and pollen.
Two attributes of honeybees which have been
essential to their evolution and biology are their clustering
behaviour and, particularly in the case of the cavity-nesting
species, their ability to cool the nest by evaporation of water
collected outside. These attributes enable the colonies to
achieve a marked degree of temperature regulation within the nest
irrespective of the external temperature. The genus Apis was thus
enabled to colonise a wide variety of environments, ranging from
tropical to cool temperate. The Meliponinae which lack this
capability are confined to tropical regions.
Another behavioural character of honeybees
is the communication of information about food sources and the
recruitment of foragers by "dance language". The
accurate dissemination of information concerning direction and
distance of forage areas leads to efficient exploitation of food
sources.
Whereas representatives of most types of
bee were indigenous to all the continents, bees belonging to the
genus Apis were originally to be found only in the Old World,
namely Asia, Africa and Europe. This suggests that the genus
appeared much later than the other types. The genus comprises
four species: Apis florea, the Little Honeybee; Apis dorsata, the
Giant Honeybee; Apis cerana, the Eastern Honeybee; and Apis
mellifera, the Western Honeybee. (Some authors include Apis
laboriosa and Apis andreniformis as separate species, but it is
likely that these are geographical subspecies of Apis dorsata and
Apis florea respectively which show greater physical variations
than the other subspecies and are possibly in a more advanced
stage of speciation.
Apis florea and Apis dorsata build single
comb nests in the open, Florea in low bushes and Dorsata in
trees. Like other tropical honeybees they are prone to
migrations, at times over considerable distances. These
migrations may be seasonal or in some cases may be a defence
against predators and parasites. Although unsuitable for
apicultural use, both these species make a major contribution to
the supply of honey and wax in the countries in their territorial
range. Human predation usually involves destruction of the nest
including the brood, but in some areas collection of honey is
practised without destruction of the nest, and some honey
gatherers even provide nest sites to which they transfer the
whole colony.
The lifestyle of Apis cerana is similar to
that of the Western Honeybees, and like Apis mellifera it is used
in apiculture with modern moveable comb hives. The numerical
strength of Cerana colonies is usually much less, and honey
yields are smaller. It is therefore being rapidly supplanted by
imported Mellifera races, chiefly A.m.ligustica.
Bees of the genus Apis are not the only
bees which contribute to the World's supply of honey and wax.
Some species of Meliponinae form very large colonies and store
sufficient honey to make their exploitation worthwhile. Modern
apicultural methods are inapplicable, but tribes of Central and
South American Indians have kept such bees in "hives"
for hundreds of years. (It should not be inferred however, that
Stingless bees are necessarily gentle and easy to handle; they
may carry out mass attacks on large intruders such as man,
inflicting painful bites with their powerful mandibles. some
species inject a caustic venom which causes severe burns to the
areas of skin affected.)
It is thought that bees originally evolved
from hunting wasps which acquired a taste for nectar and decided
to become vegetarians. Fossil evidence is sparse but bees
probably appeared on the planet about the same time as flowering
plants in the Cretaceous period, 146 to 74 million years ago. The
oldest known fossil bee, a stingless bee named Trigona prisca,
was found in the Upper Cretaceous of New Jersey, U.S.A., and
dates from 96 to 74 million years ago. It is indistinguishable
from modern Trigona. The precursor of the honeybees may have been
living about this time, but fossils of the true Apis type were
first discovered in the Lower Miocene (22 to 25 million years
ago) of Western Germany. A bee resembling Apis dorsata but much
smaller (about the size of a present day mellifera) was present
in the Upper Miocene (about 12 million years ago). It is thought
that Apis florea and Apis dorsata may have existed as separate
species as early as the Oligocene period. It has not been
possible to estimate when bees of' the Mellifera/Cerana type
first appeared on Earth. Mellifera and Cerana must have acquired
separate identities during the latter part of the Tertiary era.
The two species were apparently physically separated at the time
of the last glaciation, and there was no subsequent contact
between them until that brought about by human intervention in
recent times. In the post glacial period Mellifera and Cerana
(and to a less extent Dorsata and Florea) have shown similar
evolution into geographical subspecies, or races.
Although it has long been known that there
are many kinds of honeybee, and these have been the subject of
scientific study for more than two centuries, only in recent
years has a comprehensive classification been attempted which
takes into account not only differences in physical characters
between subspecies and their present geographical distribution,
but also the geological evidence pointing to their origins, and
to the course of their subsequent evolution and distribution.
Like the stingless bees, honeybees first
evolved in tropical conditions. The fossil record shows that at
the time the area of land that is now Europe had a tropical
climate. As the climate became cooler the open nesting types
would not have been able to survive except by migrating to the
tropical region of Southern Asia. For the greater part of the
Tertiary era Africa was isolated from Europe by sea, and no
Tertiary types of honeybee reached Africa even after a land
bridge was established. It is likely that the development of
advanced thermal homeostasis in honeybees which permitted the
occupation of cool temperate zones therefore occurred in Southern
Asia, possibly in the Himalayan region. Once established, the
cavity nesting Cerana-Mellifera type would spread East and West,
eventually occupying both tropic and cool temperate zones.
A physical separation into two groups
probably took place as a result of the glaciations which occurred
during the Pleistocene period (1 million to 25,000 years ago) and
desert and semi-desert then kept the two groups separate during
intervening warm periods. Thus Mellifera and Cerana, although
originating from a common stock, evolved into distinct species.
The ultimate Western boundary of the Cerana territory was in
Afghanistan some 600 km to the East of the nearest Mellifera
colonies in Iran. The Cerana territory comprised the Indian
Subcontinent South of the great mountain ranges, Ceylon, Malaysia
and Indo-china, and the East Indies including the Celebes, Timor
and the Philippines. In Eastern Asia it reached latitude 46, and
occupied Japan except for the island of Hokkaido.
Mellifera spread westwards through Asia
Minor to colonise the Balkans and the Mediterranean region, and
southwards through the Arabian peninsula to occupy Central and
Southern Africa. Similarities between neighbouring subspecies
suggest that the Iberian peninsula and Southern France were
colonised from North Africa
How far Mellifera bees may have penetrated
into Northern and Western Europe during the warm intervals
between the glaciations of the Pleistocene period can only be a
matter of conjecture; what is certain is that no honeybees could
have existed North of the Mediterranean region, the Iberian
peninsula and South Western France at the time of the most recent
Ice Age. Although at its maximum extent in Western Europe some
18,000 years ago, the ice sheet only reached as far as Northern
Britain, the area for hundreds of miles to the South was
inhospitable tundra.
In the warm period which followed the Ice
Age (starting about 14,000 years ago) the ice sheet gradually
retreated and the tundra was replaced by forests of birch, pine,
hazel, elm and broad-leaved oak. The Western honeybee was once
more able to extend its domain in Europe. In the East advance
beyond the Caucasian region proved impossible, owing to the lack
of suitable nesting sites in the steppes of Southern Russia The
bees of the Balkan area spread northwards to occupy the Eastern
Alpine valleys, Central Europe as far as the 50th parallel of
latitude, and the Western shores of the Black Sea. In the West
the bees which had found refuge in Southern France during the Ice
Age spread across Europe North of the Alps eventually occupying
an area from the Atlantic seaboard to the Ural Mountains. The
northernmost limit of the territory may have been in Southern
Norway; honeybee remains dating from Ca. 1,200 have been found in
an archaeological dig in Oslo although honeybees had not been
reported in Norway prior to the l9th Century. The mountain ranges
of the Alps and the Pyrenees obstructed the northward movement of
the bees in the Italian and Iberian peninsulas. however.
In colonising this vast territory,
stretching from the Urals to the Cape of Good Hope, Apis
mellifera had to adapt itself to a large variety of habitats and
climates ranging from the Continental climate of Eastern Europe
with its harsh Winters, late Springs and hot, dry Summers,
through Alpine, cool temperate, maritime, Mediterranean,
semi-desert and tropical environments. This adaptation was
achieved by natural selection, producing some two dozen
subspecies or races. All the subspecies of the Mellifera group
can interbreed given the right conditions, but the crosses show
hybridity characters.
Although Cerana bees must have shared a
common ancestor with Mellifera, they have evolved into separate
species. It is not possible to cross Cerana with Mellifera even
using instrumental insemination, because the two species are now
genetically incompatible, and viable eggs do not result from the
cross fertilisation Other differences include their differing
reactions to diseases, infestations and predators. Cerana can
tolerate varroa and has developed an effective defence strategy
against the Giant Hornet, against which Mellifera bees have no
defence. Cerana is however, highly susceptible to the acarine
mite, which arrived with the introduction of Mellifera bees into
Cerana territory. It is also highly susceptible to sac brood and
foul brood, but not markedly so to nosema.
The different races of A.mellifera can
generally be differentiated in physiological terms. Bees from
warmer climates tend to be smaller in size and lighter in colour
than those adapted to the colder regions, although this rule is
not invariable. The effect of altitude seems to be similar to
that of increasing latitude. Accurate differentiation between
races of similar appearance requires precise morphometric
examination of representative samples of bees. There are also
differences between races in natural history and biology. Some
subspecies are more prone to swarming than others, some produce
large numbers of young queens when swarming, others only a few.
Tropical honeybees frequently "abscond" or migrate,
sometimes due to lack forage through drought or other causes,
perhaps as a defence against predators. Heavy predation is also a
likely cause of the vigorous defence reaction of some races, for
example, the bees of tropical Africa.
The bees of the warmer regions do not need
to cluster as tightly as those confined to the nest through long,
cold winters. Brood rearing is adapted to take maximum advantage
of the local flora. Where bees of the same race have occupied
different kinds of habitat, they have formed local strains which
have accommodated themselves to the different conditions.
Similarly, honeybees of different races which have occupied
similar habitats have evolved similar behavioural characters.
Even the "dance language" by which honeybees
communicate information about the location of food sources may
differ in detail between races as different races may be
conditioned to foraging over different distances from the nest.
(Professor Goats described these differing dance patterns as
"honeybee dialects".)
The behavioural characters of the different
races and strains, brood rearing pattern, foraging behaviour,
clustering, etc., are fixed genetically, so that a colony cannot
readily adapt itself when transferred to a different kind of
environment.
The Dark European Honeybee, Apis mellifera
mellifera, is fairly uniform over its whole range, having had but
a comparatively short time in which regional varieties could
evolve, but even in this race differences can be observed between
strains. In France, where the bee has been domiciled longest,
there are distinct differences in brood rearing pattern between
the Mellifera bees of the Landes district in the Southwest, the
bees of the Paris area, and those of Corsica. The Landes bees are
typical "heather bees", conditioned to a principal
nectar flow in late Summer and early Autumn. In the Paris area
there is no Summer nectar flow and the bees show early Spring
brood activity. Exchange of colonies between the Landes and Paris
resulted in poor performance in both cases. In Corsica the
Mellifera bees follow a Mediterranean pattern with little or no
brood production in Summer and a second peak in Autumn.
The effect of transferring bees to
environments to which they are not adapted is graphically
illustrated by experience in the tropic zone of South America.
European honeybees have been kept in Brazil for centuries, yet
failed to establish a feral population in the country. When a few
queens of a tropical race from Africa were introduced into the
country, in a matter of a few years feral colonies of hybrids,
"africanised bees" had crossed the Amazon rain forest
and moved North and South completely eliminating the European
bees.
The behavioural patterns which have evolved
in the different races have ensured the survival of the various
subspecies in their native habitats, and some of these patterns
may be repeated in different races. There is one race which,
although of small economic importance, possesses an apparently
unique biological character which renders it of great importance
in the study of the genetics of honeybees. In all other races,
when a colony is rendered queenless, laying workers may appear
which are capable of laying drone eggs only. In A.m.capensis, the
Cape Bee, when a colony is deprived of its queen, a laying worker
appears within a few days which, for a period, is able to lay
predominantly diploid worker eggs. From these eggs true queens
capable of being mated can be raised, re-establishing
queenrightness in the colony.
Apiculture has been practised in Europe and
Asia throughout recorded history. For most of the time the
honeybees kept in any country would be indigenous to the
locality. In the New World countries, where the true honeybees,
Apinae, were originally absent, the early settlers imported the
bees with which they were familiar. Thus, Iberian bees were taken
to Brazil and North European bees to North America, Australia and
New Zealand. Whereas the Iberian bees were unsuited to the
tropical climate of South America and failed to establish a feral
population, the North European bees adapted well to the harsher
conditions and feral colonies quickly established themselves over
a wide area. Indeed, colonisation by honeybees far outstripped
that by the settlers. In New Zealand and Tasmania feral and
managed colonies of A.m.mellifera have existed in a pure state in
spite of massive importation's of Italian bees.
In most parts of the World, especially
where beekeeping is practised on a commercial scale, the Italian
bee has proved the most popular, owing to its docility, its rapid
build-up, and its ability to rear brood continuously until late
in the season as long as food is available. It is therefore
pre-eminently suitable for those countries where long, continuous
nectar flows occur from late Spring onwards. Where the nectar
flows are intermittent or are interrupted by bad weather, feeding
may be necessary during the barren periods, and also in Spring
and Autumn. A.m.ligustica cannot survive the harsh Winters of the
Northern and Midwestern states of America. Migratory beekeeping
has therefore been adopted; new colonies are raised each Spring
in the Southern states and transported to the forage grounds of
the North, where they remain until the Fall. With adequate brood
space and young queens, swarming is not a problem. At the end of
the season the colonies are destroyed. Unfortunately, one of the
desirable characters of the race, namely docility, may be quickly
lost by interbreeding with feral colonies of A.m.mellifera or its
hybrids.
Italian bees were first imported into
Britain in the middle of the last century, more as curiosities
than for any known apicultural advantage. Importation in bulk
with Government encouragement took place from 1920 onwards,
following the so-called "Isle of Wight disease"
epidemic. This disease has been equated with acarine, and
undoubtedly acarine played a part, but it seems likely that
wartime neglect, and the loss of beekeeping experience resulting
from World War I contributed to the loss of colonies. The losses
were greatest in the South of England, where the greater
proportion of beekeepers, and particularly the large bee farms,
were to be found. Even so, in spite of massive imports of Italian
bees, A.m.mellifera still exerts a dominant influence over large
areas of Great Britain and Ireland although pure examples are
comparatively rare. The Italian bee has performed well in warm
summers, particularly in the South of England, but heavy losses
usually occur during the so-called hard winters.
The other race which has been exported
world-wide is the Carniolan, A.m.carnica. In Germany the native
dark bee had been completely mongrelised by the large scale
introduction of foreign bees, chiefly Ligustica and Carnica, and
the honeybee population was generally unproductive and
aggressive. A decision was made by the Deutscher Imkerbund (the
German beekeepers association), supported by the Provincial and
Federal Governments and the majority of German beekeepers, to
convert completely to Carniolan bees, using selected strains, and
to control bee breeding by licensing breeders, so as to ensure
maintenance of the purity of the breed and improve the
productivity and other desirable attributes. This programme has
now been virtually completed, although importation of foreign
bees is still permissible under the law.
In other North European countries there has
been a tendency to move over to Carniolan bees, although in
recent years an increasing interest has been shown in
re-establishing the North European Dark Bee, A.m.mellifera, in
most countries in which it is autochthonous (the original
sub-species). The move to Carniolans or Italians is unlikely to
progress as far as Eastern Russia or Central Siberia, where the
harsh Winters and late Springs may demand a hardy bee with a late
build-up. Beekeeping in these regions is said to be possible
where the rivers are frozen for less than six months in the year,
in spite of the severe Winters. Although the post-glacial
migration of A.m.mellifera did not progress beyond the Ural
Mountains, beekeeping using the North European bee has been
practised in Siberia since the early part of last century. Only
in the easternmost province is a different race of honeybee kept;
the Ukrainian bee, A.m.macedonica, was introduced into Ussuria
towards the end of the l9th century.
Twenty five thousand different kinds of bee
have been described, divided into eleven Families, numerous
subfamilies, tribes and genera, and still more numerous species
and subspecies. Honeybees belong to the family Apidae, which
includes other social bees such as bumble bees (Bombinae), and
stingless bees (Meliponinae). The subfamily Apinae, consists of
one tribe Apini, comprising one genus, Apis. There are four
species within the genus: florea, dorsata, cerana and mellifera,
but only the last two are suitable for apiculture in modern,
moveable comb hives. Two dozen geographic races of the Western
Honeybee, Apis mellifera, have been recognised, adapted to a
range of environments from the cold Continental climate of
Eastern Europe, through the moist temperate climate of the
Atlantic seaboard, the warmth of the Mediterranean, and the heat
of the tropics and semi-deserts. Only Four of these races need be
considered for apiculture in a cool temperate climate such as
that of Britain. namely A.m.ligustica, A.m.carnica, A.m.caucasica
and the native bee of the British Isles, A m.mellifera.
It was formerly believed not only by
ordinary beekeepers but by some notable scientists, that
improvements in the desirable attributes of honeybees,
productivity, docility, resistance to disease, for example, could
be achieved by crossbreeding different races. It is well known in
other fields of bioculture that a first or second cross of two
different breeds or strains will often produce progeny which are
superior to either progenitor in some desirable character. It is
also known that such hybrids are generally unsuitable for further
breeding as the results are frequently unpredictable and
generally inferior particularly if continued through several
generations. So it is with honeybees; first or second crosses
sometimes produce colonies which give exceptional performance,
"hybrid vigour", but succeeding generations seldom
repeat this performance. Moreover, crossing of any of the four
races mentioned is likely to result in hybrids with very
undesirable characters, namely excessive stinginess and a
predilection to " following".
It is now widely accepted that the best way
to get improvement in bee stocks is by selective breeding within
a single subspecies.
It is worthwhile considering the reputed
behavioural characters of the races most likely to be chosen for
apicultural purposes in Britain. The Italian or Ligurian
honeybee, A.m.ligustica, is the foreign bee which has been
imported in greatest numbers, and has largely supplanted the
native bee in the South of England, although surprisingly, pure
or nearly pure colonies of the latter have survived into recent
years, even when surrounded by predominantly Ligurian apiaries.
Many beekeepers have found that their "Italian" bees
turned dark within the space of a few generations. Some of the
most vicious hybrids retain the bright colouring of the Italian
race, however. Further North the performance of the Italian bee
has been less impressive, and many experienced beekeepers prefer
the native bee. Carniolans and Caucasians have also been imported
into Britain but not in numbers comparable to those of the
Italian imports and generalisations about their performance under
British conditions could be misleading.
The Italian honeybee is the most widely
distributed of all honeybees, and has proved adaptable to most
climates from subtropical to cool temperate, but it is less
satisfactory in humid tropical regions. It is very prolific but
brood rearing starts late and lasts long into late Summer or
Autumn, irrespective of nectar flow. It is therefore at its
greatest advantage in those regions where favourable weather
prevails throughout the Summer, and there is a long,
uninterrupted supply of nectar. It is less satisfactory where the
main nectar flow occurs in Spring, or where the weather is
uncertain, as in the cool maritime regions. In poorer districts a
honey crop may only be obtainable at the expense of heavy Autumn
feeding.
A.m.ligustica has been described as having
a low swarming tendency with few queen cells, but this is
contrary to the experience of many beekeepers in Great Britain.
This may possibly be due to the use of brood chambers which are
too small for such prolific breeders. In the migratory beekeeping
practised in America it is usual to operate without a queen
excluder, so that the breeding area is unrestricted. It is said
that the queen seldom goes above the second lift of the hive.
Italian bees, having been conditioned to
the warmer climate of the central Mediterranean, are less able to
cope with the "hard" winters and cool, wet springs of
more northern latitudes. Their bodies are smaller and their
overhairs shorter than those of the darker races, and they do not
form such tight Winter clusters. More food has to be consumed to
compensate for the greater heat loss from the cluster. The
tendency to raise brood late in Autumn also increases food
consumption. They are unable to retain faeces in the gut for long
periods and require more frequent cleaning flights than the dark
bees; they are more likely to be lured out of the hive by bright
winter sunshine.
There is no clear evidence that Ligustica
is any more resistant to acarine than Mellifera; no epidemic
corresponding to Isle of Wight disease was ever reported from
Northern Europe. Moreover, acarine is undoubtedly a problem among
the Italian bees of the United States of America. Ligustica also
appears to be less tolerant of Nosema than Mellifera.
Ligustica tends to forage over shorter
distances than either Carnica or Mellifera, and may therefore be
less effective in poorer nectar flows. It apparently lacks the
ability to ripen heather honey before sealing.
Italian bees are much more prone to
drifting and robbing than the other principal races of Europe. It
has a reputation for gentleness, but hybrids with the darker
races can be especially vicious.
The Carniolan bee of Slovenia and Austria
is the nearest relative of the Italian, but it is larger and
darker, the characteristic yellow rings of Ligustica being
replaced by dark bands. The Carnica territory covers a large area
of south-eastern Europe, and there are numerous regional
variations. The characteristic brood rhythm is a rapid build-up
in Spring, followed by a slow decline and an early cessation of
brood rearing in the Autumn. It is particularly suited to an
early Spring honey flow. Like A.m.mellifera it can survive hard
Winters with a small winter cluster.
Carniolan bees are said to be more prone to
swarming than Italian bees , but that this tendency can be
reduced by selective breeding. In recent years selective breeding
has also been used with great effect in both Austria and Germany
to improve the productivity of the bees.
A.m.carnica are reputed to have better
homing ability than any of the other major races, and are much
less prone to drifting (and presumably to robbing). They are
sparing in the use of propolis.
Carniolan bees have a well deserved
reputation for gentleness and quietness on the comb, but their
hybrids with both Mellifera and Ligustica are said to be
particularly vicious.
The Caucasian bee closely resembles
A.m.carnica in general appearance, and may not be easily
distinguished from the latter except by morphometric examination
(longer proboscis, cubital index about 2 on average). Indeed, it
has been alleged that many bees sold as "Caucasians"
were in fact Caucasica-Carnica hybrids.
A.m.caucasica is autochthonous (the
original sub-species) to the mountain range and southern valleys
of the Caucasus, and to the eastern end of the Black Sea coast in
Anatolia. The climate varies from humid subtropical on the coast
to cool temperate in the mountains, and local strains reflect the
different climates, the bees from the mountains being larger and
darker, with longer overhair, than those from the lowland region.
The Caucasian bee is noteworthy for the
length of its proboscis, being the longest of all the mellifera
races. One might expect that this would give it an advantage over
shorter-tongued races from a foraging point of view, but this
does not seem to be borne out in practice.
Brood rearing generally starts late and the
Spring build-up is slow, leading to a medium population size in
Summer and Autumn. Swarming tendency is said to be low, and the
number of swarm cells moderate. Caucasian bees are said to be at
their best in protracted slight nectar flows; they seem to be
unable to cope with short heavy flows, most of which is stored in
the brood chamber rather than the supers. Honey cells are
"wet" capped, i.e. there is no air space between the
honey and the capping, and this may lead to "weeping"
of the comb.
Caucasian bees are notorious for their
heavy use of propolis, especially at the hive entrance. In Winter
the entrance may be almost completely closed by a curtain of
resin, leaving only a few small holes for ventilation and flight
activity. Caucasian bees have poor resistance to Nosema disease
and this may lead to heavy winter losses.
A.m.caucasica is described as having a
"high level of gentleness", and certainly it had this
reputation in the 1930's, although there was little experience of
this bee in Britain at that time. It is said to combine well with
other races, particularly Carnica and Ligustica. There has been a
report of very aggressive behaviour by "Caucasian" bees
in this country, but the bees in question may have hybridised
with local bees. They apparently showed poor wintering qualities.
The "A. mellifera" (1758) or
"A. mellifica" (1761) of Linnaeus is but one small
section of the Dark European Honeybee whose natural territory
included the island of Corsica and ranged from the Pyrenees over
Europe north of the Alps to the Ural Mountains in the East, and
included Great Britain and Ireland and southern Sweden. Although
there is no historical record of honeybees in Norway before 1775,
it is known from archaeological evidence that A.m.mellifera was
present in southern Norway round about 1200 A.D.
It is well adapted to survive in a harsh
climate. It is thrifty in its use of stores; brood rearing is
reduced when the nectar flow is interrupted. It forages over
longer distances than the Italian bee and can make better use of
meagre food resources. It will be observed foraging both earlier
and later than A.m.ligustica, and will fly in dull and drizzly
weather which would keep Italian bees indoors. It may also be
that mating can take place at lower temperatures than in the case
of the southern races. Although less prolific than Italians, the
workers live longer and there is a higher ratio of foraging bees
to hive bees. The wintering capabilities of the Dark bee are
excellent; although colony size is at all times moderate, and the
winter cluster is small, heat is conserved by the tightness of
the cluster and the large bodies and long overhair of the bees.
The "winter" bees of the northern race have the ability
to retain faeces in the gut for long periods, due apparently to a
greater production of catalase by the rectal gland in Autumn.
They are thus less dependent on cleaning flights. They are also
less likely to be lured out of the hive by bright winter sunshine
than Italian bees.
A.m.mellifera forms a compact brood nest
with pollen stored as close to the brood as possible, sometimes
below as well as above the brood. Honey is stored outside the
pollen circle.
It has often been heard said among
beekeepers that heather honey should be disposed of quickly
because it "does not keep". Another widely held belief
is that heather honey is unsuitable for winter stores. Apparently
A.m.mellifera had not heard these maxims, or if they had they
chose to ignore them. How otherwise would "heather
bees" have chosen to live for centuries in areas where there
was only the heather honey crop to support them from one year's
end to the next (and perhaps for two or more years if the weather
was bad at the time of subsequent harvests)?
The native bee of the British Isles is
renowned for the whiteness of the sealed honeycomb. The cappings
are convex and a small air space is left between the honey and
the capping. This prevents "weeping" and reduces the
risk of fermentation which might give rise to dysentery.
The swarming behaviour of A.m.mellifera is
variable, depending on the region. In heather districts the local
populations tended to be very swarmy, but some strains from the
North of Britain have shown a low inclination to swarm, with the
construction of only small numbers of swarm cells. Where the
swarming tendency is low, queen replacement takes place by
supersedure.
A.m.mellifera makes abundant use of
propolis to seal up small fissures and small gaps, and may even
construct curtains at the hive entrance in the manner of
Caucasian bees, although in general it is not as free in its use
of the resin as the latter.
The Dark European Honeybee generally had a
reputation for aggressive behaviour, but this was not the
reputation of the British bee as reported by earlier writers.
Pure strains of A.m.mellifera from different parts of Britain
have been found to be docile and easily handled. Hybrids with
other races are often highly productive, but they frequently show
a fierce temperament and proneness to "following",
highly objectionable characters in densely populated countries.
One character of the Dark bee on which all
authors seem to agree is its nervous behaviour when the hive is
disturbed. It usually manifests itself by the bees running to the
bottom of the comb where they hang in a cluster when a frame is
removed from the brood chamber. This behaviour may be extreme
with some strains; colonies of pure Mellifera bees bred from
feral bees from Skeldale in Yorkshire showed a marked tendency to
run out of the hive when smoke was used at the start of a
manipulation, although they were quiet and easily handled without
the use of smoke. On the other hand , native bees from other
parts of Britain have not shown this extreme reaction to smoke.
The gentle behaviour of the major races of
honeybee may be due, of course, to selection for this quality
over many generations; even the "skep" beekeepers of
former days would, no doubt, tend to destroy the worst tempered
bees and retain the gentler colonies.
The most urgent problem in apiculture, not
only in Britain and Ireland but throughout the world, is that of
protecting the Western honeybee against extermination by the
varroa mite. The only proven method at the present time is by
using acaricides such as Bayvarol and Apistan, but these become
less effective as immune strains of the mite evolve, and there
must be constant research to develop new products. Research on
the biology of the mite is proceeding, and alternative methods of
treatment are being sought. The ultimate hope is that
varroa-resistant strains of bees may evolve, but at best this
likely to be a very long term solution to the problem. If, as is
supposed, the separation of the Cerana and Mellifera species
occurred in (relatively) recent times, the gene which enabled
Cerana to develop a defence against varroa may still be lurking
somewhere among the genes of the Mellifera races. There is a
danger that the development of resistance among apiary stocks
might be concealed by the normal anti-varroa treatments and that
a resistant strain might be lost through the death of the queens.
A case might be made out for encouraging feral colonies in
suitable areas. In due course most if not all feral colonies will
be wiped out by varroa, and the argument that they would act as
centres of infection for apiary colonies need scarcely be
considered as they would never exist in sufficient numbers to
threaten apiary stocks - unless of course a resistant strain
evolved in the wild, in which case they might transmit through
the drones resistance to the apiary colonies,
There have been many changes in the flora
on which British bees have depended during the past 10,000 years.
Woodland has given way to downland and moorland, pasture and
arable. Agricultural methods have changed, first during the
"Agricultural Revolution" of the 18th century, and even
more drastically in the more recent "Second Agricultural
Revolution". White clover, once the principal honey crop
throughout Britain, has been largely eliminated through the
introduction of "improved pasture" based on nitrogenous
fertiliser and selective weed killer. Thousands of miles of
hawthorn hedges have been ripped out to make way for bigger and
still bigger machines, and the remaining hedges are trimmed as
closely as an ornamental hedge in a Stately Home. (Hawthorn honey
is arguably the most delicious of our native honeys.) Even
roadside verges are mown and treated with selective herbicide.
Where heather moorland has been over-grazed or otherwise
neglected, the heather has been replaced by bracken; let us hope
there will never be a shortage of wealthy sportsmen to pay for
the maintenance of the grouse moors. The latest threat to the
variety of British honey is the grubbing up of orchards to make
way for imported "supermarket" apples. Our main honey
crop is now the inferior and rather troublesome product of the
ubiquitous oilseed rape.
There have been pronounced changes in the
climate of these islands during the past 10,000 years. Following
the Ice Age there was a warm period when the land was colonised,
or perhaps re-colonised, by honeybees, and when for a time the
climate may have been almost Mediterranean in character. From
about 1335 A.D. the climate grew colder; this was the start of
the "Little Ice Age" which continued well into the l9th
century. This was typified by long cold winters with much snow
and severe frost, and frequent cold, wet summers.
The native bee survived these vicissitudes
in the wild and in apiaries, and adapted itself (if adaptation
were needed, for it is clearly a most versatile honeybee) to all
the changing conditions. Further changes in agricultural practice
can be expected but not predicted. As beekeepers we can only hope
that agriculture will become more "natural" and will
encourage the cultivation of home-grown produce of all kinds.
In the last few years there have been
extremes of weather which in the short term can be regarded as
exceptional. It has been suggested that this is part of the
"greenhouse effect" of manmade pollution causing global
warming. It is too early to separate the climatic changes due to
pollution from the short term fluctuations and long term trends
in the Earth's climate. However, careful measurements over many
years have shown changes from which inferences may be drawn. For
example, the carbon dioxide content of the atmosphere increased
from 290 parts per million in 1850 to 315 parts per million 1958,
and since then has increased further to 350 parts in 1990. The
increase up to 1950 was attributed partly to deforestation and
partly to combustion of fuels, mainly coal. The increase since
1950 is thought to be due almost entirely to the combustion of
fuels. Methane, another "greenhouse gas" has also shown
a significant increase, although the concentration of this gas is
much lower. Another and clearer indicator of global warming is
the retreat of glaciers throughout the world, and of the arctic
and Antarctic icefields which has been taking place for many
years.
There is little doubt that global warming
is already taking place. What the effect on the British climate
will ultimately be if this trend continues cannot yet be
predicted. It may become warmer and drier, or warmer and more
humid, but if global warming should redirect the ocean currents
on which our climate largely depends, then it could even become
much colder.
One further matter to which beekeepers
should be giving urgent attention is the need to improve the
social acceptability of honeybees. Too many of our colonies
become bad tempered and aggressive when disturbed, some even
attack people without this provocation. Such bees are a menace to
the public and a nuisance to the beekeeper. A swarm of bees can
be a terrifying sight to anyone unaccustomed to them, and
sensational films and newspaper articles about "killer"
bees can only affect adversely the public's perception of
beekeeping. It has been pointed out that the principal European
races of honeybee in the pure form have the reputation for
gentleness, and this character can be preserved and enhanced by
selective breeding. It is widely recognised that innate bad
temper in European bees almost invariably arises from the
crossing of incompatible subspecies. The need for the adoption in
Britain of single race beekeeping in order to improve the social
acceptability of the craft therefore becomes apparent. The
adoption of such a policy would have the added advantage that
selective breeding could then be practised to pursue other
desirable aims such as greater productivity, lower swarming
tendency and better disease resistance.
In Great Britain the economic importance of
the honeybee as a pollinator far exceeded that of the hive
products and was recognised by government at both national and
local level. Beekeeping research was financed by central
government, beekeeping instructors were employed by many county
councils, and agricultural colleges maintained beekeeping units.
During World War II a sugar ration was made available to
beekeepers ostensibly for colony feed, to ensure that beekeeping
activity was maintained in the national interest. Since the War
as agricultural productivity increased, so the public recognition
of the importance of beekeeping declined, and government
encouragement for beekeeping in recent years has been less than
lukewarm. Indeed, in some quarters there has been a tendency to
regard honeybees as pests rather than as beneficial insects. Only
the threatened extinction of the western honeybee by varroasis
has brought about a positive if somewhat muted response from
government.
It is important not only that varroasis be
brought under control, but that positive steps be taken to
improve the standard of beekeeping generally, and the quality of
the bees kept in this country with regard to temper and other
attributes. The second of these objectives is only likely to be
achieved by selective breeding on a broad front of bees of a
single race.
The Native Bee, Apis mellifera mellifera,
still exerts a dominant influence over most of the British Isles
in spite of the continuing importation of foreign races, owing to
its better adaptation to the British climate. It has proved
itself able to cope with great changes in climate and other
environmental factors, a capability which may be of critical
significance in time to come. It has a genetic inheritance
different from those of other races; indeed it may possess genes
unique to these islands, that is, not even possessed by
Continental strains of A.m.mellifera. On this consideration alone
it should be worth preserving as a gene bank.
Italian bees have from time to time given
spectacular results in honey production particularly in the South
of England and during the warm summers which typified the early
part of the present century. There is no evidence that the Native
Bee is on average inferior to the imported bee in honey yield,
and it is likely to prove superior at times and in places where
forage is less plentiful. Many beekeepers have found that honey
production has increased when they have changed over to
A.m.mellifera. It is certainly better equipped for surviving
"hard" winters. cold springs and wet summers.
The only other European bee which might
adapt successfully to our climate is the Carniolan, but the total
replacement of the whole of our honeybee popula.tion by Carniolan
bees cannot easily be envisaged. The piecemeal importation of
Carniolan bees could only perpetuate and make even worse the
present unsatisfactory situation. Far better to stop importing
all foreign bees, and concentrate on a general improvement of our
honeybee stocks by large scale selective breeding from the best
of our native colonies.
In compiling the foregoing I have drawn
heavily on the following learned and authoritative sources:
"Die Honigbiene in naturlicher umd kunstlicher
Zuchtauslese", Prof. Dr. G. Goetze; "Biogeography and
Taxonomy of Honeybees", Friedrich Ruttner; "Bees of the
World", Christopher O'Toole and Anthony Raw; "The Dark
European Honeybee", Friedrich Ruttner, Eric Milner and John
Dews. I shall not attempt to refute accusations of plagiarism and
lack of originality, but in case my understanding of these works
has been at fault, I must stress that the inferences and opinions
given in the article may not always accord with those of the
authors.
I would also like to express my
indebtedness to friends and acquaintances inside and outside the
beekeeping fraternity for the benefit of their experience over
many decades, and especially for the inspiration and example of
Rev. Eric Milner, R.N.R., who has probably forgotten more about
honeybees than most beekeepers ever learn.
Ashleigh Milner ©
BIBBA 1996
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