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

3 Components To A Productive Colony High Quality Queen High Quality Queen Large Nurse Bee Population Large Nurse Bee Population Large Foraging Force 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 Brood pattern Behavior of the queen on the combs Behavior of the queen on the combs Temperament of workers Temperament of workers Production records 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 2 nd or 3 rd 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