Beekeeping Tips for February and March
by Todd Balsiger
February and August have historically been the two months on
the opposite sides of the nectar flow to treat for varroa
mites, but this is not written in stone. There are new mite
control options and they have different temperature range
requirements and honey super withdrawal times.
- In a nutshell, we do not want our varroa mite
populations to get too high – 3200 is cited as the economic
threshold for the U.S. And we do not want to skip a
treatment window if it means that the threshold number will
be exceeded before the next treatment window.
- The need to treat should be based on your current mite
population. If you have a high mite population, you should
treat immediately. If it was today (February 11th)
your options would be Apistan and Checkmite. If you have a
low mite population, you can delay and treat in March or
April with controls that require shorter withdrawal times
before supering but higher daily high temperatures for use.
Mite Away II can be used between 50-79 degrees F and
Apiguard between 60-105 degrees F.
- Our most efficacious mite controls buys you about 4
months which includes the treatment period before you need
to treat again. It should be noted that this period can be
extended by using mite tolerant stock, screen bottom boards,
drone brood removal, powder sugar, etc.
- I think one possible and viable treatment option for
Oregon beekeepers is to use Mite Away II in the spring
(March/April) and Apiguard in August. Hopefully, before next
winter oxalic acid will be registered for use during winter
- How do you estimate how many mites you have? I will
explain two techniques: the alcohol wash and the natural
- An alcohol wash can be used to estimate varroa
populations with or without the presence of brood. It is
simply a ratio of the number of mites per given number of
bees multiplied by the total estimated bee population, and
then factoring in the varroa population hidden in the brood.
It is estimated that 2/3 of the mites are within the brood
itself. An example: brood is present, and there are 30,000
adult bees. You find 5 mites in a ¼ cup alcohol wash (about
150 bees). This is equivalent to one mite per 30 bees, or
1000 mites total on the adult bee population. Add the 2/3
hidden in the brood, and you have roughly 3000 mites, which
is close to the economic threshold number of 3200.
- The natural drop estimate for varroa population requires
full cycles of brood. Incidentally, these numbers for both
techniques come from Dave VanderDussen – the Mite Away II
proprietor. It is best to do a three day, 24 hour sticky
board drop count. Each fallen mite represents 1% of the
total mite load. This means you multiply the average drop
count by 100. An average drop count of 32 mites in 24 hours
would equal 3200 total mites, or the economic treatment
- Other tasks aside from worrying about varroa mites…
- Heft hives to find any light ones. Provide light hives
emergency feed, preferably sugar candy/fondant or frames of
honey. This is prime time for starvation, as brood
production increases energy demands. When daytime highs
exceed 55 degrees, fumagillin medicated syrup can be used
instead of fondant or frames of honey.
- Feed all colonies Terramycin in powdered sugar weekly
for three weeks to prevent American and European foulbrood.
Terramycin requires a 4 week withdrawal time between the
last antibiotic treatment and the first marketable nectar
flow. Tylosin provides up to 4 weeks of protection with a
single treatment, but there is a caveat: it is more
persistent and requires an even longer rest period than
Terramycin before supering. There is a growing problem with
Tylosin being detected in honey in the U.S.
- Look for signs of Nosema infected hives. Symptoms
include: slow build-up (best indicator), disjointed wings,
distended bloated abdomen, a lot of yellow streaks on the
outside of the colony and crawling bees outside of the hive.
These symptoms may also be associated with tracheal mites.
Make sure suspect hives have good ventilation and treat with
fumagillin syrup (follow the directions exactly, overdosing
does not help, and treat fumagillin with respect as it is
- Find and remove queenless or dead out colonies. If
pollen is actively being brought in, this generally
indicates a healthy queen and hive.
- Remove dead outs and find out why it succumbed –
queenlessness, starvation, disease? If the equipment is
disease free and in good shape (frames are not all dark,
with thick cell walls, riddled with drone brood cells),
store for future use in dry location stacked on end so air
and light can penetrate to discourage mold growth and wax
- Spring usually brings some of the wildest and windiest
weather – albeit we have already had tremendous winds this
winter. Make sure the lids are secured after you break the
- If you feel your area lacks sufficient natural nectar
flows and pollen to fuel high-energy growth to make
full-sized production colonies in time for the main nectar
flow (end of May), feed fumagillin medicated sugar syrup and
pollen substitute when the daily highs exceed 55 degrees.
- Wax moth activity dramatically picks up when the
temperatures rise. Keep an extra eye out for stored frames
that have had brood and have pollen. Moth crystals
(paradichlorobenzene) can be used for control, as well as
freezing the frames. Exposing the frames to light can
inhibit the moths, too.
- Here’s one last thought: Don’t feed pollen
substitutes too early. I would consider too early as
January, February, and maybe the first part of March. Brood
production will increase, which may exhaust winter food
supplies prematurely. It also increases activity,
metabolism, and hive moisture. The weather may be
inappropriate for cleansing flights, increasing the
likelihood of developing dysentery. Dysentery is the
quickest and most effective way of converting a slight
nosema infection into a severe one. Winter should be a time
of quiescence for the bees that enables the bees to live to
take the colony over the period when little or no brood is
being reared. My two cents worth.