Inbred Until Dead
Beekeepers and queen
breeders have been selecting queens for favorable traits for many years.
Breeding and selecting within a closed population is known as line-breeding.
Some managed sub-species maintain a single subspecies, i.e. Russian, some are
hybridized, i.e. Midnight. There have been attempts to inbreed queens for
specific traits. The challenge with exclusive sub-species and inbred species is
maintaining genetic purity usually through artificial insemination. The vitality
of homozygous, inbred, sub-species decreases with generations.
Living creatures pass
their inheritance in genes. Gene variations are called alleles. Reproducing
species inherit one set of alleles from each parent for two sets of alleles.
Alleles can be dominant, recessive or co-dominant. Cells that carry genes have
cellular bodies identified as chromosomes. Honey bees have 32 chromosomes. The
egg and sperm each have half the chromosomes or are haploid. Drones have a
haploid of 16 because they are unmated.
Crossing of unrelated
sub-species results in hybrid vigor. The offspring exceed the vitality of either
parent. This unexplained increase in life force is known as heterosis. Many more
genes with more allele pairs are possible with the hybrid. The progeny or
offspring is heterozygous. An increase in heterozygosity results in heterosis.
homozygosity and reduces heterosis. Increased homozygosity causes inbreeding
depression. The offspring lose vigor, experience slow colony build-up, lose
disease resistance, experience decreased production and higher winter loss.
Sound a little like CCD or the recent increase in viruses detected?
The main problems of
line-breeding are poor brood pattern, loss of vigor, and rapid fixation of
characteristics for good qualities with diminishing returns. That is the
challenge faced by any breeder with a closed population. The United States
basically has a closed population since 1922. There has been a very limited
importation with extensive quarantine. Queen breeders are very familiar with the
vigor of fertilized offspring after extended storage of the sperm. The airlines
always take great care with everything shipped so we know everything imported
since 1922 is outstanding quality.
The Honey Bee act of 1922
was implemented to stop the spread of diseases. Well the diseases are already
here and the bees that have developed resistance are not allowed in to help
America. There are actually two methods to re-introduce resistance –
line-breeding for positive qualities –or- homogenize several sub-species with
desired qualities. Australia and New Zealand have chosen the heterogenic
In nature a queen mates
in flight with up to 20 males with various alleles. In America she has still
mated in the closed pool. If sperm from several continental regions is
homogenized, the gene pool just went global expanding the closed population.
Drone semen from numerous sub-species is stirred together. Artificial
insemination with sperm homogenized from 20 or more drones creates a diverse
population within the hive. Only nine of 26 sub-species are in the United
States. Workers resistant to disease flourish more than
their weaker sisters. Vigorous foragers produce greater yields. Pollinators with
greater vitality get more contracts and are bred in preference by the
beekeepers. Brother Adam developed the Buckfast by some of these principles.
USDA allowed limited
Carniolan imports in 1993.
Varroa parasitized the Eastern Russia coastal region on the Primorski Peninsula.
searched Europe and Africa to develop a 'mutt" bee resistant to tracheal mites
that decimated Europe and led to the ban of 1922.
Apiaries of Navasota, Texas started importing Buckfast semen. The offspring of
this haploid genetic infusion are a different color but more importantly not as
idealistic as the original.
We live in a global society, with global trade, global travel, and disappearing
borders. The diseases, pests and parasites cross the border, but resistant bees
are stopped at the gate.
These are actual results of
heterotic bee breeding reported in Heterosis in the Honey Bee (Apis Mellifera
L.), Gladstone H. Cale, Jr. and John W. Gowen’, Dadant & Sons, Inc.,
Hamilton, Illinois and Genetics Department, Iowa State College, Ames,
Iowa Received October 10, 1955
“Heterotic effects were
demonstrated for both oviposition rate and honey yield. These effects were such that
five of the six hybrid queen groups exceeded their higher parent in oviposition rate,
and four of the groups headed by hybrid queens exceeded their higher parent for
honey yield. Expressed as a percentage of the higher parent, the egg
productivities of the hybrid queens ranged from 128 percent to 166 percent, with
an average productivity increase of 35.5 percent. Hybrid queen honey yields
ranged from 100 percent to 129 percent of the higher parent, with an average
yield over the higher inbred parent of 15 percent. The oviposition rate of the
average hybrid queen was 107.2 percent that of queens selected at random from
the stock distributed throughout the United States. The two better hybrids
exhibited productivities of 114.4 and 116.7 percent of the random stock.”
Heterosis in the Honey Bee
(Apis mellifera L.)
Gladstone H. Cale, Jr. and
John W. Gowen’
Improving Our Bee Stocks:
Why it is so difficult to do, Mr. D.W.J. Yanke Daykel Apiaries
CALE, G. H. JR, 1952
Oviposition rates and viability of eggs in Apis mel@fera L. Unpublished
Thesis. Ames, Iowa, Iowa
State College Library.
GOWENJ,. W., 1952 Hybrid
vigor in Drosophila. Heterosis. Edited by J. W. Gowen. Ames, Iowa,
Iowa State College Press.
GOWENJ, . W., and L. E.
JOHNSON, 1946 Metabolic capacity of different races of Drosophila
for egg production. Am.
Naturalist 80: 149-179.
GOWENJ,. W., J. STADLEBan, d
L. E. JOHNSON, 1946 On the mechanism of heterosis-the chromosomal
or cytoplasmic basis for
heterosis in Drosophiia melanogaster. Am. Naturalist 80: 506-
LOH, S. Y., 1949 Early
testing as a means of evaluating FI heterosis between inbred lines of
Unpublished Ph.D. Thesis.
Ames, Iowa, Iowa State College Library.
MACKENSE0N., W., 1951
Viability and sex determination in the honey bee (Apis melZ+;rera L.).
Genetics 36: 500-509.
NOLANW, . J., 1923 Two year
brood curve for a single colony of bees. J. Econ. Entomol. 16: 117-124.
ROJAS, B. A., 1951 Analysis
of a group of experiments on combining ability in corn. Unpublished
M.S. Thesis. Ames, Iowa,
Iowa State College Library.
SPRAGUEG,. F., and L. A.
TATUM19,4 2 General and specific combining ability in single crosses of
corn. J. Am. Soc. Agron. 34:
STRAUSF, . S., 1942 Genetic
mechanisms of heterosis. Unpublished Ph.D. Thesis. Ames, Iowa,
Iowa State College Library.
TABERS,. , 1954 The frequency of multiple mating of queen honey bees. J. Econ.