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 ControlVarroa Control

All colonies are infested with varroaAll colonies are infested with varroa

Our aim is to keep level of infestation lowOur aim is to keep level of infestation low

Monitoring levels of varroa is essentialMonitoring levels of varroa is essential

Must use principles of IPMMust use principles of IPM

Must not rely on only one control methodMust not rely on only one control method

IPM in PracticeIPM in Practice

MONITORINGMONITORING

Mite levels fluctuate within & between Mite levels fluctuate within & between seasons. We must carefully sample ( monitor)seasons. We must carefully sample ( monitor)

and then use best estimates to determine risk level –and then use best estimates to determine risk level – if risk elevated we control!if risk elevated we control!

We MUSTWe MUST

-- Understand bee/mite life cycleUnderstand bee/mite life cycle

-- be able to identify mite & predict be able to identify mite & predict infestation levelinfestation level

Illustration series from MartinIN: Mites of Honey BeesDadant & Sons, Inc 2001

Adult female miteenters larval cell as itcompletes development.She hides on side wallas pre-pupa spins cocoon

In 60 hours she lays1st egg (male).After 24 hours she laysfemale egg one every 24 hours

Her son (male) develops feedingon pupa & matesw/ sister as she matures

When adult beeemerges 1.3 adultfemale mites are mature – if eggson 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 LevelsMonitoring Mite Levels

Essential to know mite levelsEssential to know mite levels So as to treat at appropriate timeSo as to treat at appropriate time Not waste with unnecessary treatmentsNot waste with unnecessary treatments Know if treatment is workingKnow if treatment is working Detect reinfestation by drifting/robbingDetect reinfestation by drifting/robbing

MonitoringMonitoring

On broodOn brood - worker- worker - drone- drone

On beesOn bees - ether roll- ether roll - - powdered sugarpowdered sugar - alcohol wash- alcohol wash

In colonyIn colony- Sticky boardSticky board- Open mesh floorOpen mesh floor

ThresholdThreshold

An acceptable level of pests An acceptable level of pests [mites] – determine necessity of [mites] – determine necessity of further controlsfurther controls

A number to use to evaluate mite A number to use to evaluate mite control efficacy effortscontrol efficacy efforts

Allows estimation of risk if no Allows estimation of risk if no pesticide chemical is integrated pesticide chemical is integrated into the controlinto the control

The basis for IPM – a decision The basis for IPM – a decision process utilizing modern pest process utilizing modern pest control practicescontrol practices

IPM THRESHOLDIPM THRESHOLD

MMonitoring can supply a numberonitoring can supply a number - a “guesstimate” - a “guesstimate”

DDetermine an appropriate risk leveletermine an appropriate risk level- one mite vs 100 vs 1000?- one mite vs 100 vs 1000?

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

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

BBalance of costs vs benefitsalance of costs vs benefits

ThresholdThreshold

Quick Guide to Action NeededQuick Guide to Action Needed

Monitor natural mite drop at regular Monitor natural mite drop at regular intervals during the active seasonintervals during the active season

24 hour mite drop during active season24 hour mite drop during active season 0-2 no action needed0-2 no action needed 3-7 plan for treatment within a month3-7 plan for treatment within a month 8+ treat immediately8+ treat immediately

IPM Mite Control TriangleIPM Mite Control Triangle

Varroa Mites – cultural controlVarroa Mites – cultural controlApiary site locationApiary site location Minimise drifting and robbingMinimise drifting and robbing

• consider bees natural behaviour in the wildconsider bees natural behaviour in the wild

Co-ordination with nearby beekeepersCo-ordination with nearby beekeepers Reduce risk of re-infestationReduce risk of re-infestation

Varroa Mites – cultural controlVarroa Mites – cultural controlApiary site locationApiary site location Minimise drifting and robbingMinimise drifting and robbing

Co-ordination with nearby beekeepersCo-ordination with nearby beekeepers Reduce risk of re-infestationReduce risk of re-infestation

Requeening with Resistant (tolerant) stockRequeening with Resistant (tolerant) stock Hygienic queen stockHygienic queen stock SMR(suppressed mite reproduction)SMR(suppressed mite reproduction) Russian stockRussian stock

Varroa Mites – cultural controlVarroa Mites – cultural controlApiary site locationApiary site location

Minimise drifting and robbingMinimise drifting and robbing

Co-ordination with nearby beekeepersCo-ordination with nearby beekeepers Reduce risk of re-infestationReduce risk of re-infestation

Requeening with Resistant (tolerant) stockRequeening with Resistant (tolerant) stock Hygienic queen stockHygienic queen stock SMR(suppressed mite reproduction)SMR(suppressed mite reproduction) Russian stockRussian stock

Experimental methodsExperimental methods Small-sized cell baseSmall-sized cell base Wide frame spacingWide frame spacing Top-bar hivesTop-bar hives

Varroa Mites – physical controlVarroa Mites – physical controlScreened bottom boards (all year round)Screened bottom boards (all year round)

Drone brood trappingDrone brood trapping

Icing sugar dustingIcing sugar dusting

Swarm manipulationSwarm manipulation

Screened bottom board

Left on all year will reduce mite levels

Drone Brood TrappingDrone Brood Trapping

Will halt the build up if drone brood is Will halt the build up if drone brood is removed regularlyremoved regularly

Very effective if bait comb used in Very effective if bait comb used in broodless colonybroodless colony

Icing sugar dustingIcing sugar dusting Use proper icing sugarUse proper icing sugar Non-toxic, can be used in active seasonNon-toxic, can be used in active season Low efficiency, but repeated weekly can be beneficialLow 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 controlVarroa Mites – biological control

No identified control agent so farNo identified control agent so far

Best choice seems to be a virus or Best choice seems to be a virus or fungusfungus

Varroa Mites - Chemical ControlVarroa Mites - Chemical Control

Pesticides – natural/synthetic need to be Pesticides – natural/synthetic need to be approved (registered) for legal useapproved (registered) for legal use

Natural doesn’t mean less toxicNatural doesn’t mean less toxic

DUMB chemicals (less toxic, not pre-DUMB chemicals (less toxic, not pre-packaged) need SMART beekeeperspackaged) need SMART beekeepers

Chemical Control - OrganicChemical Control - Organic•Essential Oils

•Thymol (apiguard) – use in autumn

•Other essential oils – insufficient evidence

Chemical Control - OrganicChemical 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 -PesticidesChemical Control -Pesticides

Apistan or BayvarolApistan or Bayvarol Synthetic pyrethroidsSynthetic pyrethroids Significant resistance in most areasSignificant resistance in most areas May harm drone sperm if used in springMay harm drone sperm if used in spring May be harmful if bees forage crops treated May be harmful if bees forage crops treated

with other pesticideswith other pesticides Should only be used if a resistance test has Should only be used if a resistance test has

been carried out firstbeen carried out first

Amitraz & Coumaphos – not approvedAmitraz & Coumaphos – not approved

When should you control varroa?When should you control varroa?

Three Seasons of Varroa ControlThree Seasons of Varroa Control

WinterWinter Oxalic acidOxalic acid

Spring-summerSpring-summer Bait combs, drone trapping, sugar, splitsBait combs, drone trapping, sugar, splits Oxalic acid if broodless and not storing Oxalic acid if broodless and not storing

AutumnAutumn Thymol, formic acid, sugarThymol, formic acid, sugar

SwarmsSwarms

When preparing to swarm, egg laying is When preparing to swarm, egg laying is reduced, so more varroa are outside the cellsreduced, so more varroa are outside the cells

The new swarm has no brood, so is suitable The new swarm has no brood, so is suitable for varroa control:for varroa control: SugaringSugaring Oxalic acidOxalic acid Bait comb Bait comb

Artificial swarmArtificial swarm

Swarming Hive

QQC

QC

Artificial swarmArtificial swarm

Swarming Hive – Moved to one side

New Brood Box on old site

Q QCQC

Artificial swarmArtificial swarm

Original Hive – Moved to one side leave one open

queen cell

New Brood Box on old site

Fill with foundation

Queen on drawn comb

with only open brood

in new box

QCQ

Artificial swarmArtificial swarm

Original Hive – Moved to one side leave one open

queen cell

New Brood Box on old site

Fill with foundation

Queen on drawn comb

with only open brood

in new box

QCQ

Move over supers

Artificial swarmArtificial swarm

old site

QC Q

After 1 week

Swap to other side

Artificial swarmArtificial swarm

After 2 weeks

Virgin Queen Q

Remove and destroy frame of sealed brood with most of the varroa

Artificial swarmArtificial swarm

After 3 weeks

Virgin Queen Q

Transfer 2 frames of open brood

To act as bait combs for varroa

virgin not yet laying,

All worker brood emerged,

Destroy any remaining drone brood

Artificial swarmArtificial swarm

After 5 weeks

Laying Queen Q

Remove and destroy bait combs with most of the varroa

Bait combs now sealed

Don’t wait until you see this!

Powdered Sugar Sampling to Powdered Sugar Sampling to monitor Varroa mite populations monitor Varroa mite populations

in Honey Bee coloniesin Honey Bee colonies

3 Basic ways to Monitor Mites 3 Basic ways to Monitor Mites 1. On Brood1. On Brood

Impale capped drone pupae Impale capped drone pupae with capping scratcher and with capping scratcher and count number of cells count number of cells infested infested

= = % brood infested% brood infested

Count # brood infested not total mite count

3 Basic ways to Monitor Mites 3 Basic ways to Monitor Mites 2. Natural mite drop2. Natural mite drop

Sticky BoardSticky BoardMites dropped over three days captured on Mites dropped over three days captured on

sticky/vaseline-coated board sticky/vaseline-coated board = average mite drop/day= average mite drop/day

2mites

3 Basic ways to Monitor Mites 3 Basic ways to Monitor Mites 3. Mites on adult bees3. Mites on adult bees

Sugar rollSugar roll Shake mites off nurse bees Shake mites off nurse bees

using icing sugarusing icing sugar == mites/sample (~300 mites/sample (~300

bees)bees)

Sugar shake methodSugar shake method

Collecting a sample of adult bees (1/2 cup Collecting a sample of adult bees (1/2 cup or approximately 300) from the brood area or approximately 300) from the brood area and then vigorously shaking the sample and then vigorously shaking the sample with icing sugar (for 1 minute) causes the with icing sugar (for 1 minute) causes the majority of mites (>90%) to dislodge from majority of mites (>90%) to dislodge from their hosts. We can then shake out the their hosts. We can then shake out the mites onto a light coloured collecting dish mites onto a light coloured collecting dish and count the mites.and count the mites.

Sampling Sampling EquipmentEquipment

Measuring cup(marked at ½ cup)

Wide mouthquart Mason jarw/ modified lid(8 mesh screen)

White [mite]counting dish

Powdered sugar

tablespoon

Colony to sample

for icing sugar sampling

Icing sugar

tablespoon

Obtaining Bee SampleObtaining 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

Frame of open brood

with some capped drone cells

ObtainingObtainingBee Sample 2Bee Sample 2

Step 2: Shake bees from 1-3 brood frames into 5 gallon bucket or plastic wash basin – we preferif bees are collected from3 different frames but riskof queen injury is greater

Obtaining Bee Sample 3Obtaining 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

½ cup scoop from cardboard box

Obtaining Bee Sample 4Obtaining 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 sugarAdd powdered sugar

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

Push powdered sugar through lid mesh

Powder sugaring the bee Powder sugaring the bee samplesample

Step 6Step 6: Shake the sample : Shake the sample

vigorously for 1-2 minutes to vigorously for 1-2 minutes to

distribute the powdered sugar distribute the powdered sugar

over the bees – if bees not over the bees – if bees not

covered add more sugar. covered add more sugar.

Keep jar vertical when shaking.Keep jar vertical when shaking.

Shaking Shaking out theout the mites mites

Step 7: Invert jar over awhite dish and vigorouslyshake mites and sugar from jar – shake until no mites or powder sugar comes out

Mites (dark spots) in sugar

Optional reshake with additional sugarOptional reshake with additional sugar

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

Return bees to their hiveReturn bees to their hive

NOTE: Shaking in icing sugar does not harm the bees. NOTE: Shaking in icing sugar does not harm the bees. They will clean off the sugar and return to normal duties after release.They will clean off the sugar and return to normal duties after release.

Add another ½ tablespoon of icing sugar and reshake for Add another ½ tablespoon of icing sugar and reshake for one minute.one minute.

Calculate Number of mites/beeCalculate Number of mites/beeStep 8: You can estimate ~300in 1/2 cup and release sugar coated back into their hive.

ORTo get a more accurate count (and see if more mites are present) kill the bees w/alcohol or soap to wash thenStrain 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 NOTE: Shaking in powdered sugar does not harm the bees. They will clean off the powdered sugar and return to normal duties after release.clean off the powdered sugar and return to normal duties after release.

The sugar shake The sugar shake number of shaken mitesnumber of shaken mites is a “guesstimate” of the level of mites in is a “guesstimate” of the level of mites in the bee colony. It can be used to make a the bee colony. It can be used to make a decision on further treatment needs &/or to decision on further treatment needs &/or to assess past treatment effectiveness. It will assess past treatment effectiveness. It will enable you to monitor the development of enable you to monitor the development of mites over the season and from one mites over the season and from one season to the next.season to the next.

Deciding on what action needs Deciding on what action needs to be taken to be taken

Step 9Step 9: When was sample taken? : When was sample taken? Before supering – April/MayBefore supering – April/May

Treat when levels are 2-3 mites/sample Treat when levels are 2-3 mites/sample Mid flow (optional) –June/July Mid flow (optional) –June/July

Remove crop and treat when 10 or more mites/sampleRemove crop and treat when 10 or more mites/sample Post honey flow before final autumn brood rearing – Post honey flow before final autumn brood rearing –

Aug/Sept Aug/Sept Treat when levels are 10-12 mites/sampleTreat when levels are 10-12 mites/sample

These thresholds assume normal size colonies These thresholds assume normal size colonies with broodwith brood

Application of Results SummaryApplication of Results SummaryIt is recommended that a minimum of 2 samples be It is recommended that a minimum of 2 samples be

taken each year. Spring sampling (April to mid-taken each year. Spring sampling (April to mid-June) will help establish the colony condition June) will help establish the colony condition before/during the active season. If 2-3 or mites are before/during the active season. If 2-3 or mites are in sample colony/apiary you should perform a non-in sample colony/apiary you should perform a non-chemical IPM treatment to reduce mite buildup. chemical IPM treatment to reduce mite buildup.

At a minimum, an autumn [no later than mid-August] At a minimum, an autumn [no later than mid-August] assessment should be made of each colony/apiary.assessment should be made of each colony/apiary.

If more than 10-12 mites are shaken. further (usually If more than 10-12 mites are shaken. further (usually chemical) treatment is needed to help ensure over chemical) treatment is needed to help ensure over winter survival.winter survival.

For Additional InformationFor Additional Information

See website http://MAAREC.cas.psu.eduSee website http://MAAREC.cas.psu.edu

Courtesy Univ of GA