While seeking new ways to recover Varroa
mites from bees for laboratory assays, Paula Macedo, a University of Nebraska
Graduate Student, found a new way to check colonies for Varroa mites that is
more efficient than ether roll, and NOT necessary to kill bees to conduct the
You will need the following:
1) A wide mouth canning jar (quart or pint) with a two piece lid.
2) #8 mesh hardware cloth (or any mesh that will retain bees, but pass varroa)
3) Window Screen (or any fine mesh that will retain Varroa, but pass powdered sugar)
Retain the metal ring of the two piece lid and discard the center portion.
Cut a circle of #8 mesh hardware cloth to fit the inside of the ring.
Collect 200-300 bees in the jar. Add powdered sugar (enough to coat the bees, about 1 tsp. to 1 tbsp.) through the #8 mesh
hardware cloth lid.
Roll the jar about to distribute the sugar. Allow the jar to sit for a few minutes (NOT just a few seconds).
Then invert the jar over a piece of paper and shake to recover the mites. The bees will remain in the jar, but the mites and
sugar will pass through the #8 mesh to the paper.
The sugar will make it difficult to count the mites. Hence, pour the sugar and mites into another jar with a
fine mesh. lid. Shake again and allow the sugar to escape through the mesh. A brief shaking will usually recover about 70% of the mites, but longer
shaking will produce about 90% recovery. Dump the mites on a clean sheet of paper and count them.
There are three possible reasons for the efficacy of this technique:
1) Varroa mite legs have a sticky pad
called the empodium that helps them adhere to their host bee. The presence of
powdered sugar could make it difficult for mites to adhere to their host bee.
2) Powdered sugar stimulates the bees' natural grooming behavior.
3) The powdered sugar on the mite's body stimulates mites to release
from feeding on the host bee to groom themselves.
Plans for future studies: Powdered sugar applied to a whole colony will dislodge a few mites from their host
bees, but it is not efficient. Furthermore, the mites will eventually recover and return to their hosts.
However, when bees are isolated from nest materials, the might recovery
from exposing them to powdered sugar is impressive. Hence, in the future,
we will examine the efficiency of the technique in bulk bee cages. One limitation
to using this technique is that it is only efficient when brood is not present.
When brood is present, 70- 80% of the mites will be in sealed brood cells.
We know that the powdered sugar technique of Varroa detection is a safe, inexpensive,
and highly efficient way to check
adult bees for mites. We hope that you can find creative ways to use the technique
to lower Varroa mite infestations and reduce the frequency of chemical treatments.
Dare we even dream of eliminating them altogether?
Editor's Note: In a private communication
to me, Dr. Marion Ellis, Extension Apiculture Specialist for Nebraska, told
me that he uses this survey method for varroa detection and prefers it to
any other method. I will test it in my apiary on July 1 st with Sticky Boards
used as Controls and publish my results in August. I strongly suggest that
you try it too.
ROBUST VARROA MANAGEMENT
If you have not heard about the excitement,
research, and writings about Integrated Pest (mite) Management over the past
year, you must read only the Sport Pages or the Comics. It s a major undertaking
by our Mid-Atlantic Apiculture Research and Extension Consortium (MAAREQ including
our Beltsville Bee Research Lab.
Confined to the house because of the
darn snow, I carefully examined the Internet Bee-Line for something exciting;
and I FOUND IT! One of our most respected scientist (and my friend), Dr. Medhat
Nasr, Research Scientist of University of Guelph in Ontario, Canada, had replied
to someone on the subject of "Robust Varroa Management". Medhat had written
a quick, "off the-top-of- his-head" reply, and he gave me his permission to
publish it in my PINK PAGES. Here it is, with minor grammatic changes:
My definition of robust varroa management
is an integrated mite management system. In Ontario, we have been using, annually,
a combination of several methods for management of both varroa and tracheal
mites. These methods include:requeening
colonies every TWO years with tracheal mite-resistant h-v-qienic bee stock(1/2 of the operation each year)
2) spring treatment of formic acid in a mite-away pad (a single application formic acid
pad that was developed and LEGALLY used in Ontario since 1996-97).
3) use of 1-2 frames of drone foundation to trap mites in drone brood in the summer
and early fall, if needed. (Ed: Several bee equipment houses can supply)
4) fall treatment with APISTAN.
Our research results for evaluating the efficacy of applying this system showed that:
1) the use of tracheal mite-resistant hygienic bees slows the mite development in
bee colonies. T - racheal mite population will build very slowly and it will take more
than two years to reach a damaging level.
Hygienic bees which are able to remove greater than 75% of freeze killed drone brood
are able to reduce the varroa mite population by 30%
2) the use of a single application of formic acid in the spring is good for a full year for
tracheal mite control, and good to kill the varroa in the spring without the need to
use any Apistan strips in the spring.
3) using this system has helped Ontario beekeepers to achieve the following:
a) Reduction of the annual colony mortality from 25-40% to less than 10%
b) No sign of varroa mites developing
resistance to Apistan which has been used in Ontario for 8 years. We tested
varroa mite resistance to Apistan, which. showed Apistan is still effective
and kills >95% of varroa mites.
c) No Apistan residues have been found in
honey samples; and we are now in the' process of
testing for Apistan residues in the wax.
d) Beekeepers diversified their management
and activities. We have a group of queen producers of Buckfast, Carniolan,
And Ontario bees who are involved in the breeding program to measure mite
resistance. These beekeepers make their income from selling more than 15,000
queens/year and 6,000 'nucs"/year.
e) The total number of bee colonies is increasing for the past two years.
f) Honey production per colony has been increased by 10-20%.
When you total the costs of colony
replacement (killed by mites), 2 Apistan treatments, and loss of honey production
before this new "robust mite management" program, this new method is economically
viable and sustainable. This system is far more robust than relying on the
use of the same miticide (Apistan or Cournaphos) year after year. Also, this
program maintains healthy producing colonies year after year.
Cheers, from Medhat Nasr
I can hear the screams now: "What the
hunk does George mean when he says "proper"? Doesn't he think know what I am
Year after year, I hear of people
who have lost their honey crop because their bees swarmed, or their brood chamber
was honey bound, or their foundation was all sealed together by burr comb and
bridge comb. In most instances, the blame was placed on all kinds of crazy or
wrong reasons, because the real reason was IMPROPER supering. Although well
discussed in previous PINK PAGES, I will repeat the cardinal
points about supering, including WHEN to super, HOW MANY supers, DRAWN COMB
or FOUNDATION, and bee ENTRANCES.
FOUNDATION can NOT be used like drawn comb! When using foundation there MUST bel 0 frames of foundation
(NEVER NINE) in a super to get it PROPERLY drawn. If you have less than 10,
you have violated "bee space" and the bees will build bridge comb, burr comb,
and all kinds of strange comb in between the frames. Further, you can NOT put
on MORE THAN ONE super of foundation at a time. At least 6 or 7 frames of foundation
must be drawn and almost filled before you move the undrawn frames into the
center position and then add a second super, and likewise with the 3rd super,
and the 4th, etc. Obviously, it is easier to use DRAWN COMB. After the bees
have drawn comb, it is YOUR JOB to protect it from damage by wax moths or mice,
because it is the beekeeper's MOST VALUABLE ASSET.
WHEN to super: In Maryland, I install my FIRST
super on April 1 st with NO QUEEN EXCLUDER under it. On April 15th (Income Tax
Day), that first super should have 6-7 of the frames filled with nectar or
maybe even young brood (larvae or eggs). I very
carefully make sure the queen is NOT in that super (but down below in the
brood chamber area) and place a queen excluder under that super. Then I add
4 more supers of drawn comb plus 2 Imirie Shims on top of the first super.
By putting the supers in place ALL AT ONE TIME stimulates the bees hoarding
instinct making them work harder, but much more important, multiple supers provides
LOTS of storage room for them to store the thin watery nectar until they
have time to ripen it into honey.
In you are normal, you don't like to get hung
up in a traffic jam or wait in line to get into a movie, so you try to avoid
traffic congestion or lines of people. Bees do the same thing. The forager age
bee (over 19 days of age) does little more than forage, and does not do much
work in the brood chamber (bee nursery). That forager bee gets irked battling
through that highly congested brood chamber with all those nurse bees feeding
larva, building cell cappings, cleaning cells for the queen to lay eggs, guarding
the front entrance, etc, and would use another entrance to go to and from the
super area if it was available. That is the exact purpose of the Imirie Shim
and the upper entrance in the edge of the inner cover.
An Imirie Shim is NEVER,EVER used anywhere on a colony
except in between supers (never in the brood area). I put a Shim between the
I st and 2nd supers and another one between the 3rd and 4th supers; and hence
my foraging bees have 3 entrances to use other than the bottom board entrance:
2 Imirie Shims + the entrance cut in the inner cover.
Even if you think it won't work, your bees will
swarm anyhow, that is not the way TOM, DICK, or HARRY supers their bees, and
surely not the way DADDY used to keep bees, why don't you stop talking and just
try it. You might find out how I rarely have any swarms and
average 130 pounds of honey each year per colony in MARYLAND where the official
average yield is a paltry 29 pounds. I have led you to the water, now you must
decide whether to drink or not.