Transcript IPM for Beekeepers:

IPM for Beekeepers:
Managing Varroa Populations
Landi Simone
Essex County Beekeepers Society
June 12, 2007
Review of IPM Principles
IPM means managing pest populations,
not eradicating them.
 Understand pest life cycle.
 Monitoring is critical.
 Know treatment thresholds.
 Timing of treatments (when needed) is
critical.

Components of an IPM Program
IPM
Components
Pest Identification
Understand
Life Cycle
Monitor
Pest
Levels
Determine Treatment
Level
Determine Treatment
Stragegy
Direct Methods
(Usually
chemical)
Apply Treatment
Indirect
Methods
(Physical, mechanical,
biological, cultural)
Evaluate and
Redesign
Varroa: Pest Identification
Small pin-head size 8-legged brown to
reddish brown parasite sucks
hemolymph from bees
 Present in almost all U.S. colonies and
in most countries
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LEFT UNTREATED, WILL
CAUSE COLONY COLLAPSE
WITHIN TWO YEARS.
Life Cycle of Varroa destructor
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Adult female mite feeds on bees 5-13 days
then enters brood cell 24 to 60 hours before
capping.
Lays first egg 60 hours after capping, then
every 30 hours thereafter
First mite to emerge is male. Subsequent
mites are female, which mate with male and
feed on pupa
Mature females emerge with bee; immatures
and male remain in cell and die
Mites are transferred bee to bee in brood
nest; prefer nurse bees for cell access
Effects of Varroa: Individual Bee
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Workers
 Life span reduced by 50%
(especially bad for overwintering
bees)
 Food and wax glands damaged
 Reduced disease resistance
Drones
 Reduced sperm count
 Less likely to mate successfully
BAD QUEENS
Effects of Varroa: Colony Level

Pierced exoskeleton
permits entry of multiple
viruses normally
present but dormant in
the hive
 PMS: Parasitic Mite
Syndrome. Easily
confused with foulbrood
 Colony collapses under
viral load, usually in late
summer-fall
Seasonal Population Dynamics

Varroa is phoretic on
adult bees in winter
(ride + meal)
 Breeds in brood
come spring, esp.
drone brood.
 For every mite you
see on a bee, there
are two in the brood.
 Populations peak in
July and August
Understanding Varroa Population
Dynamics
So How Do I Know if my Bees
Have Varroa Mites????
Monitoring Pest Levels:
Powdered Sugar Roll
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Add 400 bees (about 2
fingers) in a quart mason jar
with hardware mesh screen
on top
Add 1 Tbsp. powdered sugar
& shake
Pour out sugar onto white
paper
Count mites
Release bees
Monitoring Pest Levels: Sticky
Boards
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Easiest to use with a
screened bottom board
(SBB) but can be used
without
Use commercial sticky board
or use homemade tileboard
or plastic smeared with
petroleum jelly
Place below screen for 1 to 3
days
Count mites
Convert to equivalent 24
hour count
Determine Treatment Thresholds

At a minimum, sample from late July to
mid-August:
 24-hour
natural fall on sticky board: Take
action if >50 mites
 Powdered sugar roll: Take action if > 10
mites
Treatment Thresholds in
Winter/Spring
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Late Winter Sampling (early to mid-March)
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24 hour natural fall on sticky board: Take action if
>2 mites
Spring Sampling (late March to mid-June)
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24 hour natural fall on sticky board: Take action if
>10 mites
Powdered sugar roll: Take action if >3 mites
IF YOUR BEES NEED
TREATMENT, GET IT ON
BEFORE THE END OF
AUGUST!
Unless you’d rather have dead bees….
It bears repeating….
Don’t be a mutt! Treat
your bees before
August 31 or you
won’t have bees
next spring!
What about fall honey??
How do I treat my
hives and still get a fall
crop?
 How do I keep wax
moths out of my
supers in late summer
and early fall without
using chemicals?
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One Beekeeper’s IPM Schedule
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Start removing honey supers by August 15,
one apiary at a time.
As you leave with the honey, slip sticky
boards under hives’ screened bottom boards.
Extract honey.
Return 2 - 3 days later and count mites on
sticky boards.
Determine which colonies need treatment.
IPM Schedule, cont’d.
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Return extracted honey supers to original
colonies, if possible, for bees to clean out for
a few days.
When supers are dry, stack all dry supers on
colonies not needing mite treatment. These
hives will bring in a fall crop.
Treat colonies that need it.
Repeat for the next apiary.
In October, remove all supers for storage.
Extract any fall honey the bees have
collected.
Remove Varroa Treatments
After the Specified Time
Unless you want to lose more treatment
options due to mite resistance….
Hard Chemical Treatment
Options - “Smart Chemicals for
Dumb Beekeepers” Dr. Medhat Nasr
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Apistan (fluvalinate)
 Pyrethroid
 Low toxicity to beekeeper
 Was highly effective (99%) in killing mites
 Widespread resistance due to misuse.
 Accumulates in beeswax.
Check-mite (coumaphos)
 Organophosphate
 High toxicity to beekeeper
 Was highly effective (99%) in killing mites
 Widespread resistance due to misuse.
 Accumulates in honey and in beeswax.
 May affect developing queens.
Hard Chemical Treatment
Options, cont’d.
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Amitraz
 Amidine - affects nerve receptors
 Relatively low toxicity to beekeeper; higher bee toxicity
 Queens stop laying while in use.
 Not licensed for use in the U.S. Not commercially available.
 Some resistance reported in Europe.
 Degrades quickly in honey and beeswax.
 Fenpyroximate (Hivastan) *NEW*
 Affects mitochondial electron transport
 Toxicity to humans and bees similar to Amitraz. High toxicity to aquatic
life. (Disposal issues.)
 Accumulates in beeswax.
 Not currently available under Section 18 in NJ, but NY has a Sec. 18.
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The “hard” chemicals from least to most toxic:
Apistan, Amitraz, Hivastan, Coumaphos
Fluvalinate Toxicity
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NEWS FLASH!!! New research by
Mary Ann Frasier at Penn State in 2008
indicates that Apistan (fluvalinate) is
significantly more toxic to honey bees
than previously thought.
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PENN STATE RECOMMENDS
AVOIDING APISTAN COMPLETELY.
Chemical Resistance
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Mites which survive a chemical treatment due
to a mutation live to parent subsequent
generations, passing on the resistance gene.
 Such mutations usually come with a down
side - resistant mites do not reproduce as
well as non-resistant mites if no chemical
treatment is present.
 Therefore, left untreated for a period, mite
populations will often revert to a non-resistant
state and chemical treatment will again
become effective (though not at previous
level.)
 ROTATE TREATMENTS!
Testing for Resistance
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Refer to USDA Beltsville Bee Research
website:
http://www.ars.usda.gov/Services/docs.htm?d
ocid=7474 for detailed directions
 Summary:
Staple a 3/8” x 1” piece of strip to be tested to a
piece of index card and place in a wide mouth
pint-size mason jar with screened lid cut to fit.
 Collect 1/4 cup of bees from brood nest (not
queen!) and add to jar. The hive must have >5
mites on an ether roll to do this test.
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Testing for Resistance, cont’d.
 Store jar at 86º F (30º C) for 6 hrs.
 Invert jar 10 cm above a white piece
of
paper and hit base 3 times with your hand.
 Count mites on paper. Call that # P.
 Knock bees down, remove card with strip,
add 1 cup of windshield washer fluid.
Replace screen with solid lid. Shake 5
minutes. Replace screen & pour fluid onto
filter cloth (e.g. nylon curtain fabric) held
over a bucket. Add another cup of fluid,
swirl and pour through again.
Testing for Resistance, cont’d.
 Count
the mites on the filter cloth. Call that
number F.
 The percentage of mites killed by the
chemical tested is:
% Kill =
P
X 100
(P + F)
Note: If the total number of mites P + F is less than 5,
The test is invalid. Pick another hive with more mites.
Hard Chemicals: Check-Mite
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Plastic strips with chemical: Use one for
every 5 frames of brood/bees (2 per deep
brood box.)
 97-99+% efficacy
if no resistance
 Leave strips in
42 to 45 days, then REMOVE.
 Honey supers must be off hives during
treatment. Wait two weeks after treatment
before supering. No temperature restrictions.
 Neurotoxin. Wear chemical resistant nitrile
gloves, NOT bee gloves.
 Requires Pesticide Applicator License.
Hard Chemicals: Apistan
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Plastic strips with chemical. Use one for
every 5 frames of brood/bees (2 per deep
brood box.)
 97 - 99%+ efficacy if no resistance
 Temperatures should be at least 50º.
 Leave in 42 to 56 days, then REMOVE.
 Honey supers must be off hives
during treatment. Wait two weeks
after treatment before supering.
 Wear latex gloves,
not bee gloves.
Soft Chemical Treatment
Options: “Dumb chemicals for
Smart Beekeepers” Dr. Medhat Nasr
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Thymol-Based:
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Apilife Var
Apiguard
Organic Acids
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Formic (Mite-Away II)
Oxalic
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Trickling Method
Fogging
Sugars
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Sucrocide
Powdered Sugar (“Dowda” Method)
Apilife Var
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Essential oil-based treatment: thymol, eucalyptus,
camphor, menthol in vermiculite ‘tablets’ or wafers.
 Each package contains two wafers. Break a wafer
into 4 pieces and put on top bars of brood nest.
 Repeat treatment 3 to 4 times 7-10 days apart.
 60 - 95% efficacy. Average 75%.
 Temperature dependent. Range should be 64º - 86º.
Do not use above 90º.
 No resistance reported.
 Honey supers should be off during treatment and not
put back on for 30 days following treatment.
 Use disposable latex gloves. Eye hazard. Can burn
skin.
Apiguard
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85 - 95% efficacy.
Honey supers must be removed but can be
returned immediately following treatment.
Temperature range 60º-105º.
Leave open tray of gel on brood nest for 14
days (2 in a double deep). Repeat treatment
once.
Also kills tracheal mites.
Eye damage/skin irritant. Manufacturer
recommends wearing nitrile gloves.
Organic Acids
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Formic Acid
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Oxalic Acid
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Original U.S. formulation was a gel, Apicure, but
packaging problems led to its being pulled from
the market.
Now available as liquid-soaked pad, Mite-Away II.
Trickling Method
Fogging (Not practical for most
hobbyist/sideliners.)
Lactic Acid - used in Europe; not available in
the U.S.A.
Formic Acid: Mite-Away II
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Temperatures should be between 50º-80º. If
temperatures exceed 82º in the first 7 days of
treatment, pads should be removed.
89 - 98% efficacy.
21 day treatment. Honey supers may go on
immediately after treatment but should not be
harvested for 2 weeks.
Remove outer plastic bag but not inner. Use
spacer rim and shims under pad. Apply pad
hole-side down.
Inhalation and contact hazard. Stand upwind
and use nitrile gloves. (Respirator
requirement recently rescinded.)
Mite-Away II
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Screened bottom
boards should be
closed during
treatment.
 Entrance reducers
should be removed.
Oxalic Acid, Trickling Method
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Not a stand-alone
treatment.
 Colony must be
broodless (Late October
- December.)
 Bees should be
reduced to 2 deeps, or
equivalent.
 Use acid-resistant
gloves.
 Knocks down mite
population phoretic on
wintering bees.
Oxalic Acid: Trickling Method,
cont’d.
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Make a 3.2% solution by adding 3 level
tablespoons (34 gms) oxalic acid crystals (dip
+ sweep method of measuring) to 1 liter of
1:1 sugar syrup. (Make syrup by putting 5
pounds of sugar in a 1 gallon container. Fill
with hot water & stir.)
 Use a syringe to trickle about 5 ml. of acid
solution in every space between frames
occupied by bees. (Dr. Medhat Nasr’s rule of
thumb was 50 ml total for strong colonies, 40
ml for weak, divided between the brood
boxes.)
Sugar Treatments
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Sucrocide
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Safe for bees (open brood?) and beekeeper.
Inexpensive.
Labor intensive
“Dowda” Method
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See May 2007 ABJ article by Randy Oliver.
Good, safe way to control Varroa populations
during honey flow. Efficacy depends on frequency
of application.
Sucrocide (Sucrose Octanoate
esters)
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Mix 1.5 Tablespoons
per gallon
 Spray each and every
frame of bees, both
sides.
 Repeat at weekly
intervals 3x to cover full
21 day brood cycle.
 Very labor-intensive.
 No restrictions on
honey supers.
 Temporary eye irritant.
Powdered Sugar Dusting
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Use 1 cup sugar per deep.
Place frame with metal
screen stretched over it over
frames and shake sugar on
screen.
Use bee brush to dust
through screen.
Repeat for second deep.
Approx. 1/3 of phoretic mites
will drop with each
treatment.
Repeat as often as desired weekly, bi-monthly or
monthly. Must be used with
screened bottom board.
No honey super restrictions.
Other Methods: Mineral Oil
Food Grade Mineral Oil (light viscosity:
70 FG. Available from STE Oil, Texas.
www.steoil.com
 Fogging (Pedro Rodriguez method) has
been shown not to work.
 Trickling on frames - mixed results.
Some beekeepers report good control
with very frequent use (R. Harvey) ;
others have not found any benefit. No
good scientific studies available.
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Other Methods: Drone Trapping
Deliberately introducing and culling
drone comb can be a highly effective
method of Varroa control.
 Can use commercial drone foundation
or introduce an empty frame, which the
bees will almost always draw out into
drone comb.
 Remove the comb when brood is
capped and dispose of brood + mites.
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Drone Culling
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One drone brood frame
per month can delay
necessity for other
treatments.
Two frames may be
able to eliminate other
treatments.
Drawbacks:
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If you fail to remove in
time, you’re breeding
mites. Requires an
organized beekeeper!
Long-term effects of
reducing an alreadydepleted honey bee gene
pool.
Follow-Up Monitoring
All “Dumb Chemical” treatments,
mechanical & biological methods need
“Smart Beekeepers” to follow-up by rechecking mite levels after treatment.
Failure to do so can cost you your bees.
 “Smart Beekeepers” use a variety of
techniques in combination with one
another. Find a system that works for
you and use it.
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Hope you learned something!!