Bee GeneticsBee Genetics

Clarence H. CollisonClarence H. Collison

Emeritus Professor/Dept. HeadEmeritus Professor/Dept. Head

Mississippi State UniversityMississippi State University

3 Components To A 3 Components To A Productive ColonyProductive Colony

High Quality QueenHigh Quality Queen

Large Nurse Bee PopulationLarge Nurse Bee Population

Large Foraging ForceLarge Foraging Force

The Queen’s Genetics Plus The Queen’s Genetics Plus Drones She Mates With Drones She Mates With

Determines:Determines:

Colony TemperamentColony TemperamentColony SizeColony SizeProductivityProductivity

Beekeepers evaluate queens Beekeepers evaluate queens on basis of colony on basis of colony characteristics:characteristics:

• Brood patternBrood pattern• Behavior of the queen on Behavior of the queen on

the combsthe combs• Temperament of workersTemperament of workers• Production recordsProduction records

A queen controls A queen controls fertilization by regulating fertilization by regulating

the release of spermatozoa the release of spermatozoa from her spermatheca.from her spermatheca.

Her entire supply of Her entire supply of spermatozoa is limited to spermatozoa is limited to those obtained before she those obtained before she starts egg laying, so she starts egg laying, so she

must dispense them must dispense them gradually.gradually.

Several spermatozoa are Several spermatozoa are apparently released each apparently released each

time a fertilized egg is laid, time a fertilized egg is laid, but the actual depletion rate but the actual depletion rate

is unknown.is unknown.

Colony traits change due to Colony traits change due to different matings.different matings.

Sperm clump and form layers Sperm clump and form layers in the spermatheca.in the spermatheca.

Needs to be considered when Needs to be considered when judging a queen.judging a queen.

The Average Drone Produces About 8 Million Spermatozoa

The Average Queen Receives 50 Million Spermatozoa During Her Mating Flight

Queen’s spermatheca Queen’s spermatheca normally contains 5-7 normally contains 5-7 million spermatozoa.million spermatozoa.

Queens with sperm counts less than 3 million are unable to head colonies for one season.

Drones are sexually mature at Drones are sexually mature at approximately 12 days of age.approximately 12 days of age.

Sperm count goes down after Sperm count goes down after 20 days of age.20 days of age.

All Sperm Produced By A Drone Are Genetically Identical

Sperm May Remain Viable In The Spermatheca Of A Queen For At Least Three Years

Queens Become Queens Become Sexually Mature About 5 Sexually Mature About 5 Days After EmergenceDays After Emergence

May Become Drone Layers If May Become Drone Layers If Bad Weather Keeps Them Bad Weather Keeps Them

FromTaking Mating Flight(s) FromTaking Mating Flight(s) For Over 20 DaysFor Over 20 Days

(Lose Urge To Mate)(Lose Urge To Mate)

Queen Mating FlightQueen Mating Flight 1-2 Weeks Old When She Goes On Her 1-2 Weeks Old When She Goes On Her

Mating Flight(s)Mating Flight(s) Almost Always Mates In The AfternoonAlmost Always Mates In The Afternoon Circles Hive Several Times To Orient To Circles Hive Several Times To Orient To

The Location Of The HiveThe Location Of The Hive Flies Low To The Ground, Less Than 15 Flies Low To The Ground, Less Than 15

Feet High To Get Away From The Hive Feet High To Get Away From The Hive Area (Believed To Prevent Inbreeding)Area (Believed To Prevent Inbreeding)

Altitude Of 20 To 100 Altitude Of 20 To 100 Feet Is The Only Area Feet Is The Only Area Where Drones Will Be Where Drones Will Be

Attracted To HerAttracted To Her

Queen Mating Flight IIQueen Mating Flight II Flies A Long Way Before Going Up In Flies A Long Way Before Going Up In

The Breeding AltitudeThe Breeding Altitude Mates With 7-15 DronesMates With 7-15 Drones Mates With A Drone Every 2-5 Mates With A Drone Every 2-5

SecondsSeconds Gone From The Hive About 13 Gone From The Hive About 13

MinutesMinutes Has A Combined Flight Range Of Has A Combined Flight Range Of

About ½ To 1 MileAbout ½ To 1 Mile

40% Of Queens Mate On First 40% Of Queens Mate On First FlightFlight

May Take 2May Take 2ndnd or 3 or 3rdrd Flights Flights

Post-Mating BehaviorPost-Mating Behavior

Queen Begins To Lay Approximately 48 Queen Begins To Lay Approximately 48 Hours After Mating FlightHours After Mating Flight

Once Egg Laying Begins, A Queen Will Once Egg Laying Begins, A Queen Will Not Mate AgainNot Mate Again

Drone Congregation AreasDrone Congregation Areas

Drone Congregation Areas IDrone Congregation Areas I

Drones congregate in definite areas Drones congregate in definite areas outside the hive.outside the hive.

Follow definite flight lanes as they Follow definite flight lanes as they approach these areas.approach these areas.

The same congregation areas are used The same congregation areas are used year after year.year after year.

Drone Congregation Areas IIDrone Congregation Areas II

Generally all drones visit a given Generally all drones visit a given congregation area in the vicinity of the congregation area in the vicinity of the hives.hives.

Drone congregation areas vary in size.Drone congregation areas vary in size.

Boundaries marked by a vertical relief Boundaries marked by a vertical relief (trees, building, hill etc.)(trees, building, hill etc.)

Drone Congregation Areas IIIDrone Congregation Areas III

Drones fly at about tree top level.Drones fly at about tree top level.

When they reach a point marked by a When they reach a point marked by a clearing among trees, an open hollow clearing among trees, an open hollow or a slight summit, they assemble and or a slight summit, they assemble and wait for a queen.wait for a queen.

Normally fly between 11:00 a.m. and Normally fly between 11:00 a.m. and 4:30 p.m.4:30 p.m.

Since A Queen Mates With Since A Queen Mates With Several Drones Some Of Several Drones Some Of

Her Daughters Have Her Daughters Have Different Fathers And Different Fathers And

Some Share The Same Some Share The Same FatherFather

Super-Sisters- Share An Super-Sisters- Share An Average Of 75% Of Their Average Of 75% Of Their

GenesGenes

Half-Sisters- Have About Half-Sisters- Have About 25% Of Their Genes In 25% Of Their Genes In

CommonCommon

Queens Must Mate Queens Must Mate With Unrelated With Unrelated Drones To Get Drones To Get

Different Sex AllelesDifferent Sex Alleles

Queens Sometimes Lay Queens Sometimes Lay Inviable Eggs Because Inviable Eggs Because

Of A Single Gene Of A Single Gene Resulting In A Shotgun Resulting In A Shotgun

Brood PatternBrood Pattern

If A Queen Is Mated To If A Queen Is Mated To A Closely Related A Closely Related

Drone, She Is Likely To Drone, She Is Likely To Produce Scattered Produce Scattered

BroodBrood

There Are There Are Approximately 20 Approximately 20

Different Sex Alleles In Different Sex Alleles In The Honey Bee The Honey Bee

Population, All Of Them Population, All Of Them At Approximately Equal At Approximately Equal

FrequencyFrequency

A Larva That Has Two A Larva That Has Two Different Sex Alleles Will Different Sex Alleles Will Develop Into A Normal Develop Into A Normal

Female (Worker Or Female (Worker Or Queen)Queen)

A Larva That Has Two Of The A Larva That Has Two Of The Same Sex Allele Will Develop Same Sex Allele Will Develop

Into An Abnormal MaleInto An Abnormal Male

(Diploid Drone)(Diploid Drone)

Diploid Drone Larvae Are Diploid Drone Larvae Are Eaten By Nurse Bees When Eaten By Nurse Bees When They Are Less Than A Day They Are Less Than A Day Old, Leaving An Empty CellOld, Leaving An Empty Cell

Because Of This Problem Because Of This Problem With Identical Sex Alleles, It Is With Identical Sex Alleles, It Is Important That Queens Mate Important That Queens Mate With Drones With Different With Drones With Different

Genetic BackgroundsGenetic Backgrounds

Mating Has Permanent Mating Has Permanent Effects On Queen Effects On Queen

Behavior, Physiology Behavior, Physiology And Resultant Queen-And Resultant Queen-

Worker InteractionsWorker Interactions

(Richard et al. 2007)(Richard et al. 2007)

Mating Stimulates Mating Stimulates Vitellogensis (Formation Of Vitellogensis (Formation Of Yolk Protein) And Oocyte Yolk Protein) And Oocyte

Maturation (Egg Formation) In Maturation (Egg Formation) In The Ovaries Which Prompts The Ovaries Which Prompts The Initiation Of Egg-LayingThe Initiation Of Egg-Laying

(Tanaka & Hartfelder 2004)(Tanaka & Hartfelder 2004)

Mating Alters The Pheromone Mating Alters The Pheromone Profiles Of Queens Allowing Profiles Of Queens Allowing

Them To Regulate Many Them To Regulate Many Different Aspects Of Worker Different Aspects Of Worker

Behavior And Colony Behavior And Colony OrganizationOrganization

Insemination Quantity Insemination Quantity Significantly Affects Significantly Affects

Mandibular Gland Chemical Mandibular Gland Chemical Profiles, Queen-Worker Profiles, Queen-Worker

Interactions And Brain Gene Interactions And Brain Gene ExpressionExpression

(Richard et al. 2007)(Richard et al. 2007)

Virgin Queens Were Virgin Queens Were Compared To Single Drone Compared To Single Drone Inseminated And Multiple Inseminated And Multiple Drone (10) Inseminated Drone (10) Inseminated

Queens Queens

Multiple Drone Inseminated Multiple Drone Inseminated Queens Elicited A Stronger Queens Elicited A Stronger

Retinue Response Than Retinue Response Than Single Drone InseminationsSingle Drone Inseminations

It Takes Numerous It Takes Numerous Drones To Fully Drones To Fully

Inseminate A QueenInseminate A Queen

Clear Direct Benefits Clear Direct Benefits Of A Queen Mating Of A Queen Mating

With Multiple DronesWith Multiple Drones

(Tarpy 2003)(Tarpy 2003)

A Fully Filled A Fully Filled Spermatheca Results Spermatheca Results

In A Longer Egg-In A Longer Egg-Laying Life SpanLaying Life Span

Increases The Likelihood Of Increases The Likelihood Of Having A Sufficient Supply Of Having A Sufficient Supply Of

Stored Semen And Lower Stored Semen And Lower Probability Of InbreedingProbability Of Inbreeding

End Up With A Variable And End Up With A Variable And Cosmopolitan Worker Cosmopolitan Worker

PopulationPopulation

Queens That Mate With Many Queens That Mate With Many Drones Will Ensure That Drones Will Ensure That

Some Of Her Workers (half on Some Of Her Workers (half on average) Will Inherit average) Will Inherit

Favorable Alleles From Their Favorable Alleles From Their FatherFather

A Queen That Mates Only A Queen That Mates Only With A Single Drone Runs With A Single Drone Runs

The Risk Of Carrying Alleles The Risk Of Carrying Alleles That Are Susceptible To A That Are Susceptible To A

Particular DiseaseParticular Disease

Queens That Mate With Queens That Mate With Multiple Drones Ensure At Multiple Drones Ensure At

Least Some Of Her Workers Least Some Of Her Workers Will Be Resistant To The Will Be Resistant To The

DiseaseDisease

Any Trait Could Be Impacted Any Trait Could Be Impacted By Increased Genetic By Increased Genetic

Diversity Within The Colony Diversity Within The Colony As A Result Of The Queen As A Result Of The Queen

Mating With Multiple DronesMating With Multiple Drones

Beekeepers Need To Be Sure Beekeepers Need To Be Sure That Their Queens Are That Their Queens Are

Properly Inseminated With A Properly Inseminated With A Generous Assortment Of Generous Assortment Of

Drone Genotypes So That The Drone Genotypes So That The Worker Population Is Worker Population Is

Similarly VariableSimilarly Variable

There Are Indirect Benefits Of There Are Indirect Benefits Of Multiple Matings For Colony Multiple Matings For Colony

Health And ProductivityHealth And Productivity

Drones Carry Different Genes Drones Carry Different Genes For A Wide Variety Of TraitsFor A Wide Variety Of Traits

When A Queen Produces When A Queen Produces Worker Offspring Sired By Worker Offspring Sired By

Different Males, The Workers Different Males, The Workers Vary From Each Other Vary From Each Other

GeneticallyGenetically

There Are Biological There Are Biological Advantages To Queens Advantages To Queens

Mating With Multiple Drones Mating With Multiple Drones Providing A Genetically Providing A Genetically Diverse Worker ForceDiverse Worker Force

More Stable And Resilient More Stable And Resilient Division Of LaborDivision Of Labor

Genetic Task Genetic Task SpecializationSpecialization

Higher Genetic DiversityHigher Genetic Diversity

May Enable Colonies To Extract May Enable Colonies To Extract Resources From The Environment Resources From The Environment More EfficientlyMore Efficiently

Brood Nest Temperatures Are More Brood Nest Temperatures Are More StableStable

Reduces Susceptibility To Various Reduces Susceptibility To Various Pathogens and ParasitesPathogens and Parasites

Genetically Diverse SwarmsGenetically Diverse Swarms

Established New Colonies Established New Colonies FasterFaster

Built More CombBuilt More Comb

Had More Frames Of BroodHad More Frames Of Brood

Higher Foraging LevelsHigher Foraging Levels

Higher Weight GainsHigher Weight Gains

Genetic DiversityGenetic Diversity

Increased Colony FitnessIncreased Colony FitnessDisease ResistanceDisease ResistanceGreater ProductivityGreater Productivity