Bee Genetics Clarence H. Collison Emeritus Professor/Dept. Head Mississippi State University

Bee Genetics
    Clarence H. Collison
Emeritus Professor/Dept. Head
 Mississippi State University

3 Components To A
    Productive Colony

High Quality Queen
Large Nurse Bee Population
Large Foraging Force

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

  Colony Temperament
      Colony Size
      Productivity

Beekeepers evaluate queens
on basis of colony
characteristics:

 • Brood pattern
 • Behavior of the queen on
   the combs
 • Temperament of workers
 • Production records

A queen controls
 fertilization by regulating
the release of spermatozoa
  from her spermatheca.

Her entire supply of
 spermatozoa is limited to
those obtained before she
 starts egg laying, so she
   must dispense them
         gradually.

Several spermatozoa are
 apparently released each
time a fertilized egg is laid,
but the actual depletion rate
        is unknown.

Colony traits change due to
different matings.

Sperm clump and form layers
in the spermatheca.

Needs to be considered when
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
normally contains 5-7
million spermatozoa.

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

Drones are sexually mature at
approximately 12 days of age.

Sperm count goes down after
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
Sexually Mature About 5
 Days After Emergence

May Become Drone Layers If
 Bad Weather Keeps Them
FromTaking Mating Flight(s)
     For Over 20 Days

    (Lose Urge To Mate)

Queen Mating Flight
 1-2 Weeks Old When She Goes On Her
  Mating Flight(s)
 Almost Always Mates In The Afternoon
 Circles Hive Several Times To Orient To
  The Location Of The Hive
 Flies Low To The Ground, Less Than 15
  Feet High To Get Away From The Hive
  Area (Believed To Prevent Inbreeding)

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

Queen Mating Flight II
 Flies A Long Way Before Going Up
    In The Breeding Altitude
   Mates With 7-15 Drones
   Mates With A Drone Every 2-5
    Seconds
   Gone From The Hive About 13
    Minutes
   Has A Combined Flight Range Of
    About ½ To 1 Mile

40% Of Queens Mate On First
          Flight

 May Take 2nd or 3rd Flights

Post-Mating Behavior
 Queen Begins To Lay Approximately 48
 Hours After Mating Flight

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

Drone Congregation Areas

Drone Congregation Areas I
 Drones congregate in definite areas
 outside the hive.

 Follow definite flight lanes as they
 approach these areas.

 The same congregation areas are used
 year after year.

Drone Congregation Areas II
 Generally all drones visit a given
 congregation area in the vicinity of the
 hives.

 Drone congregation areas vary in size.

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

Drone Congregation Areas III
 Drones fly at about tree top level.

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

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

Since A Queen Mates With
 Several Drones Some Of
   Her Daughters Have
  Different Fathers And
  Some Share The Same
          Father

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

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

Queens Must Mate
   With Unrelated
   Drones To Get
Different Sex Alleles

Queens Sometimes Lay
Inviable Eggs Because
   Of A Single Gene
Resulting In A Shotgun
     Brood Pattern

If A Queen Is Mated To
   A Closely Related
Drone, She Is Likely To
   Produce Scattered
        Brood

There Are
   Approximately 20
Different Sex Alleles In
    The Honey Bee
Population, All Of Them
At Approximately Equal
      Frequency

A Larva That Has Two
Different Sex Alleles Will
 Develop Into A Normal
   Female (Worker Or
         Queen)

A Larva That Has Two Of The
Same Sex Allele Will Develop
   Into An Abnormal Male

      (Diploid Drone)

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

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

Mating Has Permanent
  Effects On Queen
Behavior, Physiology
And Resultant Queen-
 Worker Interactions
      (Richard et al. 2007)

Mating Stimulates
 Vitellogensis (Formation Of
  Yolk Protein) And Oocyte
Maturation (Egg Formation) In
 The Ovaries Which Prompts
 The Initiation Of Egg-Laying
        (Tanaka & Hartfelder 2004)

Mating Alters The Pheromone
Profiles Of Queens Allowing
  Them To Regulate Many
Different Aspects Of Worker
    Behavior And Colony
        Organization

Insemination Quantity
    Significantly Affects
 Mandibular Gland Chemical
   Profiles, Queen-Worker
Interactions And Brain Gene
          Expression
        (Richard et al. 2007)

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

Multiple Drone Inseminated
Queens Elicited A Stronger
  Retinue Response Than
Single Drone Inseminations

It Takes Numerous
   Drones To Fully
Inseminate A Queen

Clear Direct Benefits
 Of A Queen Mating
With Multiple Drones
      (Tarpy 2003)

A Fully Filled
Spermatheca Results
  In A Longer Egg-
  Laying Life Span

Increases The Likelihood Of
Having A Sufficient Supply Of
   Stored Semen And Lower
   Probability Of Inbreeding

End Up With A Variable And
  Cosmopolitan Worker
       Population

Queens That Mate With Many
  Drones Will Ensure That
Some Of Her Workers (half on
    average) Will Inherit
Favorable Alleles From Their
          Father

A Queen That Mates Only
 With A Single Drone Runs
The Risk Of Carrying Alleles
 That Are Susceptible To A
    Particular Disease

Queens That Mate With
 Multiple Drones Ensure At
Least Some Of Her Workers
  Will Be Resistant To The
          Disease

Any Trait Could Be Impacted
   By Increased Genetic
Diversity Within The Colony
 As A Result Of The Queen
Mating With Multiple Drones

Beekeepers Need To Be Sure
   That Their Queens Are
Properly Inseminated With A
  Generous Assortment Of
Drone Genotypes So That The
    Worker Population Is
     Similarly Variable

There Are Indirect Benefits Of
 Multiple Matings For Colony
  Health And Productivity

Drones Carry Different Genes
 For A Wide Variety Of Traits

When A Queen Produces
 Worker Offspring Sired By
Different Males, The Workers
    Vary From Each Other
         Genetically

There Are Biological
  Advantages To Queens
Mating With Multiple Drones
 Providing A Genetically
   Diverse Worker Force

More Stable And Resilient
   Division Of Labor

Genetic Task
Specialization

Higher Genetic Diversity
May Enable Colonies To Extract
Resources From The Environment
More Efficiently
Brood Nest Temperatures Are More
Stable
Reduces Susceptibility To Various
Pathogens and Parasites

Genetically Diverse Swarms

Established New Colonies
Faster
Built More Comb
Had More Frames Of Brood
Higher Foraging Levels
Higher Weight Gains

Genetic Diversity

Increased Colony Fitness
   Disease Resistance
   Greater Productivity