IPM Mite Control Thresholds - PowerPoint

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IPM Mite Control Thresholds - PowerPoint Powered By Docstoc
					THE OLD
SOLUTION
           “Resistant”
           mites
           increase
           with each
           generation
           Due to:
           (1)selection
           pressure
           (2)Sub-
           optimal
           exposure
Varroa mite – a pest or vector?


                     Damage to the colony is the result of
                     virus transmission; we should not wait
                     until we can see mites on bees or
                     damaged bees before we act.
          Varroa Control
All colonies are infested with varroa
Our aim is to keep level of infestation low
Monitoring levels of varroa is essential
Must use principles of IPM
Must not rely on only one control method
                IPM in Practice
MONITORING
    Mite levels fluctuate within & between seasons.
We must carefully sample ( monitor)
and then use best estimates to determine risk level –
if risk elevated we control!
                We MUST
- Understand bee/mite life cycle
- be able to identify mite & predict
      infestation level
Adult female mite
enters larval cell as it
completes development.
She hides on side wall
as pre-pupa spins cocoon




Illustration series from Martin
IN: Mites of Honey Bees
Dadant & Sons, Inc 2001
In 60 hours she lays
1st egg (male).
After 24 hours she lays
female egg one every
24 hours
Her son (male)
develops feeding
on pupa & mates
w/ sister as she
matures
When adult bee
emerges 1.3 adult
female mites are
mature – if eggs
on drone 3X are mature
After 4-11 days from
emerging, the mite
will enter a cell 1-2
days before sealing




                        On average, 1.3 new adult mites
                        will survive from worker cells, but
                        3-4 will survive from drone cells
       Monitoring Mite Levels
Essential to know mite levels
   So as to treat at appropriate time
   Not waste with unnecessary treatments
   Know if treatment is working
   Detect reinfestation by drifting/robbing
                       Monitoring
On brood
- worker
- drone

 On bees
- ether roll
- powdered sugar
- alcohol wash

In colony
 -   Sticky board
 -   Open mesh floor
 Threshold
An acceptable level of pests
[mites] – determine necessity of
further controls
A number to use to evaluate
mite control efficacy efforts
Allows estimation of risk if no
pesticide chemical is integrated
into the control
The basis for IPM – a decision
process utilizing modern pest
control practices
             IPM THRESHOLD

            Monitoring can supply a number
                     - a “guesstimate”

           Determine an appropriate risk level
              - one mite vs 100 vs 1000?

The level at which treatment is needed will depend on the
      level, and type, of virus infection in the colony

USA Assumption: 3000 mites in fall represents a minimally
          acceptable conservative risk???

               Balance of costs vs benefits
Threshold
Quick Guide to Action Needed
Monitor natural mite drop at regular
intervals during the active season
24 hour mite drop during active season
   0-2 no action needed
   3-7 plan for treatment within a month
   8+ treat immediately
IPM Mite Control Triangle
Varroa Mites – cultural control
Apiary site location
   Minimise drifting and robbing
     • consider bees natural behaviour in the wild
Co-ordination with nearby beekeepers
   Reduce risk of re-infestation
Varroa Mites – cultural control
Apiary site location
   Minimise drifting and robbing
Co-ordination with nearby beekeepers
   Reduce risk of re-infestation
Requeening with Resistant (tolerant) stock
   Hygienic queen stock
   SMR(suppressed mite reproduction)
   Russian stock
Varroa Mites – cultural control
Apiary site location
   Minimise drifting and robbing
Co-ordination with nearby beekeepers
   Reduce risk of re-infestation
Requeening with Resistant (tolerant) stock
   Hygienic queen stock
   SMR(suppressed mite reproduction)
   Russian stock
Experimental methods
   Small-sized cell base
   Wide frame spacing
   Top-bar hives
Varroa Mites – physical control
Screened bottom boards (all year round)
Drone brood trapping
Icing sugar dusting
Swarm manipulation
Screened bottom board




         Left on all year will reduce mite levels
     Drone Brood Trapping
Will halt the build up if drone brood is
removed regularly
Very effective if bait comb used in
broodless colony
                  Icing sugar dusting
         Use proper icing sugar
         Non-toxic, can be used in active season
         Low efficiency, but repeated weekly can be beneficial




Remember – it does not kill the mites,
so they need to be trapped on a
screened floor (bee-proof)
Varroa Mites – biological control
 No identified control agent so far
 Best choice seems to be a virus or
 fungus
Varroa Mites - Chemical Control
 Pesticides – natural/synthetic need to be
 approved (registered) for legal use

 Natural doesn’t mean less toxic
 DUMB chemicals (less toxic, not pre-
 packaged) need SMART beekeepers
    Chemical Control - Organic
•Essential Oils
  •Thymol (apiguard) – use in autumn
  •Other essential oils – insufficient evidence
    Chemical Control - Organic
•Essential Oils
  •Thymol (apiguard) – use in autumn
  •Other essential oils – insufficient evidence

•Organic Acids !caution-caustic
  •Oxalic acid – use when brood free, usually winter
  •Formic acid – with dispensers can be used in
  autumn (MiteAway II may be available soon)
  •Lactic acid – out of favour as difficult to apply
Chemical Control -Pesticides
Apistan or Bayvarol
   Synthetic pyrethroids
   Significant resistance in most areas
   May harm drone sperm if used in spring
   May be harmful if bees forage crops treated
    with other pesticides
   Should only be used if a resistance test has
    been carried out first
Amitraz & Coumaphos – not approved
When should you control varroa?
    Three Seasons of Varroa Control

Winter
   Oxalic acid
Spring-summer
   Bait combs, drone trapping, sugar, splits
   Oxalic acid if broodless and not storing
Autumn
   Thymol, formic acid, sugar
                  Swarms
When preparing to swarm, egg laying is
reduced, so more varroa are outside the cells
The new swarm has no brood, so is suitable
for varroa control:
   Sugaring
   Oxalic acid
   Bait comb
Artificial swarm




            QC
       Q    QC


  Swarming Hive
Artificial swarm




                                      QC
                                 Q    QC


New Brood Box on old site   Swarming Hive – Moved to
                                   one side
               Artificial swarm

Queen on drawn comb
with only open brood
in new box




                                                   QC
                          Q
                New Brood Box on old site   Original Hive – Moved to
                                            one side leave one open
                Fill with foundation               queen cell
               Artificial swarm

Queen on drawn comb
with only open brood                        Move over supers
in new box




                                                     QC
                          Q
                New Brood Box on old site     Original Hive – Moved to
                                              one side leave one open
                Fill with foundation                 queen cell
     Artificial swarm
     After 1 week




QC
             Q
           old site


          Swap to other side
               Artificial swarm
                  After 2 weeks




                                  Remove and destroy
                                  frame of sealed
                                  brood with most of
Virgin Queen
                  Q               the varroa
                         Artificial swarm
                            After 3 weeks
virgin not yet laying,
All worker brood emerged,
Destroy any remaining
drone brood


   Virgin
   Queen                          Q

                            Transfer 2 frames of open brood
                            To act as bait combs for varroa
                        Artificial swarm
                           After 5 weeks



Bait combs now sealed



  Laying
  Queen                        Q


                                   Remove and destroy bait combs
                                   with most of the varroa
Don’t wait until you see this!
Powdered Sugar Sampling to
monitor Varroa mite populations
  in Honey Bee colonies
    3 Basic ways to Monitor Mites
          1. On Brood
Impale capped drone pupae
  with capping scratcher and
  count number of cells
  infested
     = % brood infested




                               Count # brood infested
                                not total mite count
   3 Basic ways to Monitor Mites
       2. Natural mite drop
Sticky Board
  Mites dropped over three days captured on
         sticky/vaseline-coated board
   = average mite drop/day




                                               2
                                              mites
3 Basic ways to Monitor Mites
   3. Mites on adult bees
            Sugar roll
             Shake mites off nurse bees
             using icing sugar
                 = mites/sample (~300
                  bees)
      Sugar shake method
Collecting a sample of adult bees (1/2 cup
or approximately 300) from the brood area
and then vigorously shaking the sample
with icing sugar (for 1 minute) causes the
majority of mites (>90%) to dislodge from
their hosts. We can then shake out the
mites onto a light coloured collecting dish
and count the mites.
Sampling
Equipment
                                                     Icing sugar
                                    Powdered sugar
 Measuring cup                                       tablespoon
(marked at ½ cup)
                       tablespoon


                                                           White [mite]
                                                          counting dish

    Wide mouth
   quart Mason jar
   w/ modified lid
   (8 mesh screen)
                                                     Colony to sample




                for icing sugar sampling
 Obtaining Bee Sample




Step 1: Open colony to brood cluster – Select 1 or
        more frames w/ open brood & nurse bees
        - look to be certain queen is not on frame
Obtaining
Bee Sample 2


Step 2: Shake bees from
1-3 brood frames into 5
gallon bucket or plastic
wash basin – we prefer
if bees are collected from
3 different frames but risk
of queen injury is greater
Obtaining Bee Sample 3




Step 3: Scoop up a ½ cup sample of bees (~300 adults)
  from bucket – if you shake bucket, bees will clump
    together for ease of obtaining bee sample
  Obtaining Bee Sample 4
                                     Modified lid (screen mesh
                                       replaces solid top)




Step 4: Transfer ½ cup bees to wide mouth mason jar
  and screw on lid with modified 8 mesh screening
           Add powdered sugar




Push powdered sugar
 through lid mesh



   Step 5: Add 1-2 heaping tablespoons icing sugar to
     bees in the sample jar through modified screened lid
     Powder sugaring the bee
             sample

Step 6: Shake the sample
vigorously for 1-2 minutes to
distribute the powdered sugar
over the bees – if bees not
covered add more sugar.
Keep jar vertical when shaking.
                                           Shaking
                                           out the
                                           mites
                                Mites (dark spots) in sugar




Step 7: Invert jar over a
white dish and vigorously
shake mites and sugar from
jar – shake until no mites or
powder sugar comes out
Optional reshake with additional sugar
Add another ½ tablespoon of icing sugar and reshake for
one minute.

Shake out sugar with mites
until no more drop -- count
total number of mites

Return bees to their hive




           NOTE: Shaking in icing sugar does not harm the bees.
    They will clean off the sugar and return to normal duties after release.
   Calculate Number of mites/bee
Step 8: You can estimate ~300
in 1/2 cup and release sugar coated
back into their hive.
          OR
To get a more accurate
count (and see if more mites
are present) kill the bees w/
alcohol or soap to wash then
Strain sample to count
number of bees -- divide
number of mites by # bees
        = # mites/bees

    NOTE: Shaking in powdered sugar does not harm the bees. They will
  clean off the powdered sugar and return to normal duties after release.
The sugar shake number of shaken mites
is a “guesstimate” of the level of mites in
the bee colony. It can be used to make a
decision on further treatment needs &/or to
assess past treatment effectiveness. It will
enable you to monitor the development of
mites over the season and from one
season to the next.
 Deciding on what action needs
          to be taken
  Step 9: When was sample taken?
     Before supering – April/May
        Treat when levels are 2-3 mites/sample
     Mid flow (optional) –June/July
        Remove crop and treat when 10 or more mites/sample
     Post honey flow before final autumn brood rearing –
      Aug/Sept
        Treat when levels are 10-12 mites/sample

These thresholds assume normal size colonies
  with brood
Application of Results Summary
It is recommended that a minimum of 2 samples be
    taken each year. Spring sampling (April to mid-
    June) will help establish the colony condition
    before/during the active season. If 2-3 or mites are
    in sample colony/apiary you should perform a non-
    chemical IPM treatment to reduce mite buildup.

At a minimum, an autumn [no later than mid-August]
  assessment should be made of each colony/apiary.
  If more than 10-12 mites are shaken. further (usually
  chemical) treatment is needed to help ensure over
  winter survival.
  For Additional Information
See website http://MAAREC.cas.psu.edu




                      Courtesy Univ of GA

				
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