Stan’s Place
Hi, from the big mouth:
Well, this is February & time is Flying (pun). You should
be looking at the food situation in your hive. Colonies could be light &
need a boost. They might have food but won’t move over, so you might quickly,
on a good day, do a bit of manipulation & also have a better idea of what
is going on. Dry sugar on the inner cover or sugar in an inside feeder will
also do.
Now is the time to tweak the hives with a pollen substitute
if you want to increase or split your hive.
If you haven’t considered fixing &/or replacing equipment,
you should do so before the busy time is upon you. If you have some frames
that you have questions about, bring them in a plastic bag to the next meeting
and we will try to identify and discuss.
There is an I.P.M. workshop planned for Duncan in March.
There is room for about 30 – 50 people, only, so book early - Sunday, March
10th, 10:00 A.M. at the Beekeepers Hall. Contact Frank Whitton at 250-478-4944
in Victoria.
Brenda’s Buzz Line
Thanks to Hedy and Conrad who have provided the great content
for this issue. Any others interested in a particular topic and willing to
write an article, now’s the time.
Conrad is again offering his bee course at Malaspina. This
was a great intro to beekeeping for me – both theory and lots of hands on
stuff. Starting Saturday, February 23rd. Call Malaspina to register
or check out Conrad’s webpage at http://www3.telus.net/conrad.
Last month we held elections and we have a new line-up of
executive and friends. President – Stan Reist; Vice-president – Sol Nowitz;
Treasurer & Membership – Diana Prestidge; Co-Secretaries – Conrad Berube
and Arlene Watts;
Directors – Paulo Benvin, Bill Hall
and Hedy Thomas; Bee Drugs – Elaine Kuusisto; and Coffee/Tea – Ed Pyrz. Thanks
to all those stepping forward to help make this club happen.
Fees for next year are going up. $50 will pay for BCHPA membership
fee, insurance and the Nanaimo Club portion.
Frank Whitton needs to hear from you if you want the Integrated
Pest Management (I.P.M.) workshop to go ahead. The more people that attend
the less cost for everyone (see Stan’s Place). The meeting next Wednesday
would be a great time to organize a car pool. Conrad and I will also be giving
an overview on IPM at the next meeting.
Imidacloprid and the "French Bee Syndrome"
By Conrad Bérubé (February 2002)
Imidacloprid was introduced as a seed treatment in France
in the early 1990's to control aphids in sunflowers. The aphids do not directly
damage sunflowers but can transmit a harmful virus. By eliminating aphids
during the vegetative growth of the sunflower it is possible to slow the spread
of the virus to acceptable levels. Beekeepers in the areas where the Gaucho®
seed dressing was used on sunflowers noted a significant decline in honeybee
populations and honey production around the same time that the imidacloprid-treated
seeds were introduced. These declines and the symptoms observed with them
became known as the "French Bee Syndrome".
Imidacloprid is a pesticide that kills in a way similar to
that in which nicotine does. Both pesticides affect nerves by mimicking the
action of the chemical transmitter acetylcholine. However, the chemical message
cannot be "turned off" in the manner that acetylcholine is -- so
that nerves fired by these compounds continue to fire long after the initial
exposure to the pesticide. In the
case of fatal poisoning (of insects or mammals) enough nerves are damaged
by these pesticides that twitching, convulsions and death result in short
order. Of course negative impacts can show up prior to death and, conversely,
there are lower limits of exposure at which substances are not considered
toxic.
For instance, in the case of imidacloprid and bees,
at doses greater than 20 mg/kg foraging bees were stimulated to dance faster than
normal (which would convey distances to nectar sources closer than they actually
were, thus adversely impacting the ability of bees to communicate the location
of nectar sources.) We can consider
levels of 20 mg/kg
as the lower limit of no observable adverse effect.
In table 1 it is shown that imidacloprid is more toxic than
nicotine is to honeybees and less toxic to mammals. (For interest's sake I put information on fluvalinate (Apistan®)
in for comparison-- which shows that imidacloprid is less toxic to mammals
[or at least rats] than are either nicotine or fluvalinate [remember the bigger
the LD50 value for species the less toxic it is to that species]).
Table 2 summarizes the cases for and against an association
between the "French Bee Syndrome" and seed treatments of imidacloprid.
Personally, I find the evidence unconvincing that imidacloprid
applied as a seed treatment was in any way responsible for the French bee
syndrome. It seems much more likely that symptoms attributable to a pathogen
(such as viruses causing paralysis that can be associated with Varroa infestations)
only became prominent concurrently with the introduction of Guacho®-treated
sunflower seeds.
However, it would also seem worth investigating whether the
imidacloprid spray formulation Admire® 240 F may have been used illegally
at some sunflower sites in France. Given the proven efficacy of imidacloprid
as a seed treatment it certainly seems within the sphere of possibility that
some sunflower growers may have used the spray formulation of imidacloprid
on the blooming crop -- contrary to legal restrictions in France. This abuse
may also be of concern to Canadian beekeepers. Imidacloprid as a spray formulation
is registered, as Admire® 240 F, for outdoor use on potato, tomato, field
lettuce, and apple throughout Canada and has an emergency use label in Ontario
only against Prunus species. An application has been made to the Pest Management
Regulatory Agency requesting a similar emergency registration for
Admire® 240 F for use in blueberries (to control a virus
transmitted by aphids). The risks to bees associated with a spray formulation
are much greater than those for a seed treatment of the
same active ingredient. Canadian beekeepers should ensure that appropriate
compliance protocols are in place before Admire® 240 F is made more widely
available.
References:
Adams,R. Handbook for
Pesticide Applicators and Dispensers.
1992. BC Ministry of Environment.
Bogdanov, S., V. Kilchenmann, and A. Imdorf. Acaricide residues in honey, beeswax and propolis.
Swiss Bee Research Centre. 1999.
Extoxnet (Extension Toxicology Network). http://ace.orst.edu/info/extoxnet/pips/fluvalin.htm
Extoxnet (Extension Toxicology Network). http://ace.orst.edu/info/extoxnet/pips/imidaclo.htm
Julien, D. Protecting
Honeybees from Pesticides. 1999. http://www.bmi.net/roseguy/beespray.html
Lusby, D.A. Recycling Beeswax: Epilogue http://www.beesource.com/pov/lusby/part13.htm
Schmuck, R. No causal
relationship between Gaucho® seed dressing in sunflowers and the French bee syndrome. Pflanzenschutz-
Nachrichten Bayer. 1999. v 5 (3)
p. 257-299
Stark, J.D. Limitations
to use of topical toxicity data for predictions of pesticide side effects
in the field. Journal of economic entomology. Oct 1995.
v. 88 (5) p. 1081-1088.
Tasei, J.N. Hazards
of imidacloprid seed coating to Bombus
terrestris (Hymenoptera: Apidae) when applied to sunflower. Journal
of economic entomology. .June 2001. v. 94 (3) p. 623-627.
Theo’s Field days
You are invited to join Theo Fredrich every second
Saturday of the month for a field day at his place. Theo will be working his
(and the club) hives and encourages interested members to come. Meeting time
is 10:00 am at 2798 Cedar Road. To confirm, Theo’s number is 245-4214.
Honey Bee Defense
Submitted by Hedy Thomas
I found the information in The Biology of the Honey Bee by Mark Winston, 1987, Pg 114-116 very
interesting. I had tried to increase one of my colonies last year. I found
nothing but a heap of dead bees in the new colony. The original hive was doing
just fine thank-you very much. I tried it again and the very same thing happened.
The new hive had no stores left and all of the bees were dead. I also noted
some very nice shiny smooth black bees in the original hive. The following
excerpts/summary from Winston’s book help to explain the mystery.
“Honey bees have different tactics for defense. Attempts
to chase away vertebrates usually involve biting, hair-pulling and eventually
stinging. Other insects are more difficult to sting consequently, attacks
by insects are met with more grappling behavior. In response to ants, workers
at the entrance turn away, fan the wings and kick their rear legs, which frequently
succeeds in preventing the ants from entering the nest. Wasp attacks may be
met by shimmering behavior, whereby workers shake violently side to side,
which often dissuades the attackers. Some of the most elaborate defense behaviors
are actually designed to prevent other honey bee colonies from robbing.
“Honey bees are quite opportunistic in foraging and any rich
source of honey may be quickly discovered and exploited. The richest source
of honey normally available in the field is not flowers but the honey stored
by another colony. Robbing behavior occurs whenever one colony's bees can
gain access to another colony's nest and remove the honey. This kind of attack
can last for days and leave thousands of dead bees. The behavior of guards
at the entrance is largely designed to protect bee colonies from members of
their own species.
Robbing generally does not occur during periods when resources
are readily available in the field; at such times, guard bees often permit
foreign workers to enter their nests after careful and prolonged inspection
and dominance interactions. These workers are often adopted by the new colony.
However, the behavior of potential robbers is quite different from that of
drifting and disoriented foragers from other colonies. It elicits more intense
defensive behavior from guard bees. Robbers become aware of the presence of
a concentrated honey source in another bee colony by perceiving the strong
honey odor coming from the colony entrance. These odors are strongest at the
end of the summer, when colonies are full of honey, and fanning to cool the
nest and evaporate nectar is at its peak. Potential robber bees often exhibit
a characteristic hovering and sideways flight pattern at the nest entrance.
When this erratic flight pattern, as well as the foreign odor of robbers are
recognized by guard workers at the entrance, they quickly respond with ferocious
attacks. The guard and robber grab hold of each other's legs, curl their abdomens
and attempt to sting each other while rolling together in a cartwheel-like
motion. Usually one or the other worker is seriously injured or dies. If the
robber is successful at gaining entry to the colony, she will ingest a load
of honey and return to her colony, recruiting other workers to rob the attacked
colony. If the robbing colony is more populous than its victim's it can clean
out all the honey, which can result in the death of the robbed colony. Once
robbers have been trained to locate the rich honey source in other colonies,
they may continue searching for additional colonies to attack. Robbers become
shiny, smooth and almost black, as a result of the occupational hazards of
fighting with other bees.
“Honey Bees also have various mechanisms for defense against
fungi and microorganisms which can attack stored products or the bees themselves.
Honey has its own chemical defense , as it contains glucose oxidase enzymes,
which break down glucose and release hydrogen peroxide, an antibacterial agent.
It also has a high osmotic pressure owing to its high sugar content, which
inhibits fungal growth. Stored pollen is protected in part by the thin layer
of honey which covers it in cells, but some pollens may themselves contain
antibiotics which provide further protection.
“Bees exhibit some behavioral resistance to bee diseases,
for example, American foulbrood, which is caused by the bacteria Bacillus
larvae and kills honey bee brood. Workers from disease resistance lines remove
dead larvae and pupae from the nest more quickly than susceptible lines, thereby
reducing the source of infection. “
Bee Swap
Do you need something? Do you have something for
sale? List here for free! Contact Brenda.
Address changed?
Canada Post has been busy updating the rural route system.
If your address has changed, please let me know. Thanks - phone and fax 247-2078,
email jagreid@island.net.
Next Meeting
Fourth Wednesday, February 27, 2002 at 7:30 p.m.,
at Fairview Community School. Located at Second street and Howard Avenue.
Room is located off second street parking lot. Two
doors down from the Gym.
