Midnite Bee-Beekeeper's: Article November 1999
1) WHAT are they?
2) WHAT do they do?
3) How much do YOU know about them?
4) How important are they for good bee MANAGEMENT?
5) Will they be M OR E important for bee management in the 21 st century?
6) How much more SCIENTIFIC RESEARCH has to be done?
The word PHEROMONE was first used in regard to honey bees just 40 years ago
in 1959. During the first 35 years, 1959-1984, honey bee research money was
steadily being reduced not only in our federal laboratories, e. g. Beltsville
Bee Lab, but much more so in the university research facilities around the nation.
This was due to many things, but surely the fact that all bee diseases were
well under control primarily due to state inspection programs, and the fact
that it was difficult to "sell" the importance of honey bee pollination of our
food crops to university administrations. The arrival of the tracheal mite in
1984 coupled with an almost immediate multitudinous loss of colonies, followed
by the more serious Varroa mite in 1987 materially altered the subjects of honey
bee research almost overnight due to the carnage caused by these two mites in
49 of our 50 states.
The research scientist, particularly the biochemists, biologists, and organic
chemists had to leave the sanctity of their laboratories and work with professional
apiculturists, queen breeders, and even some hobbyist scientists like me to
further understand the natural BEHAVIOR of the honey bee.
This research quickly produced Amitraz, Apistan, Menthol and more recently
Formic acid and Coumaphos, which are the ONLY APPROVED chemicals for use against
the mites today. However, perhaps of greater importance, the research for these
colony saving chemicals led to scientists uncovering the role of honey bee pheromones
and some of the chemical formulas that made up these pheromones, so that we
can now even synthesize some of these important chemicals to create artificial
I feel strongly that the beekeepers of 21st century will find that knowledge
of honey bee pheromones is as important to successful beekeeping as computers
have become to our mode of life over the past few years, or how the micro wave
oven has totally changed our cooking methods during these same years.
Hence, let's talk about these CHANGING TIMES and learn more about PHEROMONES.
1) WHAT are they? I am sure that you have told your wife that you loved her;
or told your children the evils of premarital sex; or told your restaurant that
"the soup was cold"; or telephoned your distant parents on Mother's Day; or
wrote a letter of explanation to Internal Revenue Service about the tax deduction
you took. You COMMUNICATED! You transferred your thoughts to another human being
by using your voice, or telephone, or by writing a letter. Make a note that
this communication can only be done between members of the same species, and
it would fail if you tried to communicate with your pet canary, cat, hog, a
passing deer, or your honey bees.
Pheromones are chemical MESSENGERS, secreted by one honey bee that elicits
a behavioral or physiological response by another honey bee. It is produced
as a liquid and transmitted by direct contact as a liquid or as a gas (a smell
as we think of pretty perfume or the stink of a skunk).
Honey bees use pheromones to COMMUNICATE with each other in much the same way
we humans use our voice. This communication is primarily used for the interactions
of members of the same colony; and it is thought (but not yet proven) that the
colony is regulated chemically by the pheromones produced by the queen.
We now know that worker bees and drones produce as well as respond to pheromones,
and, equally we know that the queen produces and uses pheromones considerably
more than the other two castes. Pheromones are NOT single chemicals (unfortunately),
but rather a complex mixture of numerous chemicals in various different percentages
of the total.
Further, one single pheromone may have multiple functions, and, in contrast,
a single behavioral response probably involves more than one pheromone. I trust
that you will note the intense complexity caused by these many variables; and
then when you consider the extremely minute amount of a given chemical that
is a portion of the issue of one bee as a message to the other colony members,
you can begin to appreciate the difficult task presented to a chemist to identify
or synthesize these chemicals.
However, technology has had almost exponential growth over the last 50 years,
and the chemists of the next century will identify these now unknown chemicals
and even synthesize them. After all, who had ever heard of atomic energy or
fission when I reported to Oak Ridge National Lab to develop new methods of
purifying uranium and man made plutonium 55 years ago in 1944?
Pheromones must be divided into two different classifications: RELEASER pheromones
that trigger an almost immediate behavioral response from the receiving bee;
and the PRIMER pheromones which cause the receiver bee to exhibit an ALTERED
BEHAVIORAL RESPONSE at some future time.
Although this division of releaser and primer pheromones is our current understanding
of their actions, it is important to realize that a single pheromone can function
as BOTH a releaser and primer under certain specific conditions.
2) WHAT do they do? In BROAD generalities, pheromones affect many things, such
as: mating, swarming, alarm behavior, security, social togetherness, sexual
attractant, inhibition of queen rearing and ovarian development in workers,
the glue that holds a large population of bees together as a single functioning
unit, a "homing" message to other colony members, queen supersedure caused by
loss of pheromone, inhibition of queen cell development on the "face" of the
comb, and numerous other actions.
Let's talk about the more important pheromone effects.
Perhaps the most important pheromones to most beekeepers are two of the many
chemicals produced in the Mandibular Glands of the Queen:
9-ODA (9-oxo-2-decenoic acid) This chemical not only inhibits queen rearing
as well as ovarian development in worker bees, but is a strong sexual attractant
for drones when on a nuptial flight. It is critical to worker recognition of
the presence of a queen in the hive.
9-HDA (9-hydroxy-2-decenoic acid) This chemical promotes stability of a swarm,
or a "calming" influence to the natural excitement'of a 9warm.
These two chemicals, 9-ODA and 9-HDA, are often referred to as "queen substance".
We know that this COMBINATION perform critical functions of worker retinue formation
and development of colony cohesion. It is this combination that acts as the
"glue" that binds all the elements of colony segments, even very large populations,
into a SINGLE functioning colony unit.
A QUEEN LOSES THE ABILITY TO MAKE "QUEEN SUBSTANCE" EVERY DAY OF HER
LIFE AS SHE AGES! Hence, a 12 months old queen is an
"OLD" queen who cannot produce enough queen substance to prevent swarming when
the population begins to become large. This might be "nature's way" of honey
bee expansion, but it sure ruins a good honey yield for that season. A new queen,
produced in August or March will rarely swarm in the buildup period of April,
May, and June because they are young enough to produce adequate supplies of
queen substance which prevents swarming.
Often overlooked, is the "footprint pheromone", the oily secretion of the queen's
tarsal glands that is deposited on the comb as the queen walks across them.
This pheromone, which also diminishes as the queen ages, inhibits queen cell
construction (thereby inhibiting swarming)
Many beekeepers are familiar with the Nasonov (Nassanoff) Gland Pheromone,
and often remark about seeing bees "scenting". This gland produces at least
7 different terpenoids, the most abundant being geraniol and citral. These are
easily synthesized cheaply and are used as swarm attractants or "homing" pheromones
to a swarm trap. In normal use the worker bees spread the Nasonov scent when
foraging for water to aid other water foragers to the site, "scenting" at the
doorstep of the colony to guide colony bees home, and scenting at a new site
during a swarming procedure to notify other swarm members "Here we are, over
here!". The queen is not thought to produce this pheromone; and is able to utilize
her queen substance to aid workers to find her if need be.
All beekeepers are quite familiar with the STING ALARM, although many are not
aware that this is a pheromonal action. The KOSCHEVNIKOV gland, near the sting
shaft, produces an alarm pheromone consisting of more than 40 chemical compounds,
of which isopentyl acetate (IPA) is note worthy due to its banana odor. When
a bee stings you, the stinger and venom sac is left impaled in your flesh; and
the banana odor of the alarm pheromone signals to other workers to aid in the
attack and plant another sting close to the impaled stinger emitting the odor.
It is of interest that IPA inhibits bees from scenting with the Nasonov gland.
Hence queenless workers can find their queen by Nasonov scenting, but release
sting alarm pheromones upon finding a foreign queen, and this IPA is used to
promote aggression against an alien queen. Does this explain why a new queen
must be INTRODUCED for several days to a colony before she will be accepted?
It is known that comb -building worker bees synthesize certain oxygenated compounds
in the new comb as they construct it. We now believe that these compounds give
freshly prepared wax comb its characteristic odor that pheromonally stimulate
the hoarding behavior of foraging bees.
Drones produce a pheromone that attracts other flying drones to promote the
formulation of drone aggregations at sites suitable for mating with virgin queens.
Believe it or not, there are BROOD pheromones. The presence of brood (both
larvae and pupae) in a colony inhibits the ovarian development in worker bees.
Hence, you rarely find evidence of a laying worker in a colony that still has
live brood. Further, nurse bees can readily distinguish worker and drone larvae
and pupae is correlated with the presence of brood recognition pheromones.
And there are more, and then, MORE; but in 1999, research scientists just have
not yet had the time or funds to delve into these fascinating 11mysteries" of
"the life of the honey bee". As I have said many times, it is only now that
I regret my advanced age knowing that I will not be on the scene as science
throws light into this now darkened area. Wow, wouldn't it be great to be a
young scientist at the beginning of this 21st century to explore the underpinnings
of the ice berg tip in honey bee pheromones, outer space, medical advancement,
and learning to live in the speed of the computer age.
3) How much do YOU know about pheromones? If you have made it this far reading
my writings, you surely know more than most other beekeepers. I only hope that
I have awakened your appetite to read some more and pheromone research
4) How important are they to good bee MANAGEMENT? With a better understanding
of pheromones, a beekeeper would have many less swarms, have higher forager
populations, increased honey production, receive less stings, learn to manage
bees without wearing all those hot protective clothes, and find the JOYS OF
BEEKEEPING! If all those things are not enough to excite you to learn more about
pheromones, I suggest that you find another less scintillating hobby like stamp
collecting or identification of rocks or something else that is dead rather
than vibrantly alive because of your knowledge and aid to honey bee survival.
5) Will they be MORE important in honey bee management in the 21st century?
Just ask your neighbors or a group of unknowns on Main Street in America: Do
you object to honey bees on your neighbors lot, or are you allergic to bee stings?
America is no longer a rural country and over 80% of our population are city
dwellers. Many adults have never experienced a single bee sting in their lives,
and the Hollywood "terror" films about "killer bees" have made the American
public almost frantic in fear of a single bee sting. Hence, the old saying of
"not in my back yard" comes into play. By you knowing more about pheromones,
you will better MANAGE your bees; and hence, you will have less swarms than
now that might wind up in your neighbor's yard or even under the eaves of his
roof. Further, by you working your bees with little or no protective clothing
will demonstrate to the public that their fear of honey bees is unfounded. Lastly,
because of your pheromonal knowledge, your bees will make much more honey because
of your improved management skills, and, hence you will have plenty of honey
"gifts" for your neighbors, church, and clubs.
6) How much more SCIENTIFIC RESEARCH has to be done? Maybe you can tell me
how much more scientific research we have to do before we establish living facilities
on the planet MARS; or how much more until we find a shot that prevents cancer,
or how much more before we can go over to London for lunch and be back home
in a couple of hours. There is a tremendous amount of research yet to be done
regarding the role of pheromones in the life of the honey bee colony, but the
hard part, i. e., just knowing that pheromones play a very important role in
the lives of honey bees, is already done. Now, it is just a matter of finding
the money to support pheromonal research among honey bees in our schools of
scientific learning today. I hope that I have made a good case for you to learn
more about the role of pheromones in beekeeping; and I will give you some time
to digest this. Probably my next topic has even greater bearing on UPGRADING
BEEKEEPER'S KNOWLEDGE, and that is: Understanding BEE BEHAVIOR