Swarming Biology of Honey Bees

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Swarming Biology of Honey Bees Jeff Harris Extension/Research Apiculturist Department Biochemistry, Molecular Biology, Entomology & Plant Pathology Mississippi State University, MS 39762

(ca. 10-14 days old) Mississippi Agricultural & Forestry Experiment Station Reproductive Swarms Left at the old nest site are between 12-25 queen cells About 40% of the original nest bees Usually

1 Swarming Biology of Honey Bees Jeff Harris Extension/Research Apiculturist Department Biochemistry, Molecular Biology, Entomology & Plant Pathology Mississippi State University, MS Reproductive Swarms Seasonal most active months are May and June Usually the swarm consists of old queen and about 60% of the original nest bees Most workers in this type of swarm are very young (ca days old) Mississippi Agricultural & Forestry Experiment Station Reproductive Swarms Left at the old nest site are between queen cells About 40% of the original nest bees Usually these bees are old bees, many of which are foragers Types of Swarming Reproductive swarms (primary) Afterswarms (secondary) The function of primary swarms is reproduction by colony fission Absconding swarms 1

Not All Primary Swarms Survive Only 8-25% of primary swarms survived through the first season (cold climates) 45-78% of those swarms that survived the first season continue to survive for about 5

2 Not All Primary Swarms Survive Only 8-25% of primary swarms survived through the first season (cold climates) 45-78% of those swarms that survived the first season continue to survive for about 5 years Events of Swarming Rapid growth in amount of worker brood Crowding of the colony Queen cup construction Queen cell construction (10-15 days prior) Good weather Engorgement of Honey Exodus Afterswarms Fairly uncommon, but in our area 1-2 afterswarms might issue from a colony per year Afterswarms usually contain a virgin queen, or recently mated queen Many queens can occur in an afterswarm Afterswarms are smaller than primary swarms and do not survive through a season in temperate climates Causes of Swarming Dilution of queen pheromone Lack of space for queen to lay eggs Abundance of resources Genetic strain of bees Age of queen Environmental conditions Absconding Swarms Pre-Swarm Conditions Also called migration When nest site has become intolerable: 1. Chronically low abundance of food 2. Disease conditions 3. Insecticide poisoning 2

Colony Growth Colony Growth Thousands of Bees 45 40 35 30 25 20 15 10 5 0 Nov. Dec. Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Number of cells 12000 10000 8000 6000 4000 2000 0 worker drone May June July Aug.

3 Colony Growth Colony Growth Thousands of Bees Nov. Dec. Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Number of cells worker drone May June July Aug. Sept. Oct. Crowded with Good Nutrition Number of Drones Reared % Drone brood Total Brood (square cm) x 1000 Timing of Swarming New York: May-June, peaks in June Pennsylvania: May-June, peaks in late May Arkansas: April-May, peaks in early May Louisiana: March-May, peaks in April Many Queen Cups weeks from swarming 3

Getting Ready to Swarm Broodnest Many queen cups Eggs in cups Capped cells Time until Swarming go time, swarming in weeks will swarm in 8-10 days any moment While In Flight Worker and queen

a structure (bush, tree or building) within a few hundred yards of original nest site Finding the New Home 1. Scouts search out cavities 2. Scouts communicate cavity information using dances 3.

4 Getting Ready to Swarm Broodnest Many queen cups Eggs in cups Capped cells Time until Swarming go time, swarming in weeks will swarm in 8-10 days any moment While In Flight Worker and queen pheromones hold the mass of bees together Appears wildly chaotic, but calms quickly on landing Swarm Cells located on bottom of combs (easily seen by tilting back brood boxes) Bees assemble on a structure (bush, tree or building) within a few hundred yards of original nest site Finding the New Home 1. Scouts search out cavities 2. Scouts communicate cavity information using dances 3. Colony-wide debate 4. A choice is made (all dances are the same) Emergency Queen Cells located anywhere, and they are usually shorter than swarm cells 5. Chaotic exodus (again) 6. Land at new site 4

Back at the Old Nest Site Preventing Swarming Virgin queens emerge from cells Multiple virgins

often ball unwanted queens 1. Reversing hive bodies 2. Adding supers 3. Splits / nucs / increases 4.

Checker boarding Virgin queens participate in afterswarms Reversing Hive Bodies Queen cells being

Checker boarding Broodnest Likely time of Swarm Open brood is present recent, 0-4 days Sealed but

5 Back at the Old Nest Site Preventing Swarming Virgin queens emerge from cells Multiple virgins tolerate each other only for a brief period Queens do fight to the death on occasion, but workers often ball unwanted queens 1. Reversing hive bodies 2. Adding supers 3. Splits / nucs / increases 4. Shake nurse bees in front of weaker colony 5. Checker boarding Virgin queens participate in afterswarms Reversing Hive Bodies Queen cells being chewed down after a virgin queen has emerged It Already Swarmed! Checker boarding Broodnest Likely time of Swarm Open brood is present recent, 0-4 days Sealed but no open brood more than 4-5 days No brood but there swarmed > 3 weeks, are remains of queen cells new queen not laying yet Multiple eggs in cells > 28 days ago, new queen failed, laying workers 5

6 Causes of Swarming European vs. Africanized Dilution of queen pheromone Lack of space for queen to lay eggs Abundance of resources Genetic strain of bees Age of queen Environmental conditions At the time of swarming, Africanized bees are actively rearing brood in 90% of the total nest volume European bees only rear brood in ½ to ¾ of the available nest volume European Bees 1. Initiate queen rearing prior to swarming when: a. Cluster occupies liters (5-7 gallons) b. Brood area is 8000 cm 2 (1,240 sq. inches) c. Adult worker population is about 12,000 bees 2. Swarm issues when adult bee population is at least 20,000 bees Africanized Bees and Swarming Africanized bees have seasonal primary swarms, although the season is longer Food resources are committed to biomass (more brood) by Africanized bees Tend to issue out many afterswarms that can survive in tropical climate Tend to abscond a nest site when food is unavailable sooner than European bees will under the same conditions Africanized Bees 1. Initiate queen rearing prior to swarming when: a. Cluster occupies 40 liters (10-11 gallons) b. Brood area is 23,000 cm 2 (3,565 sq. inches) c. Adult worker population is about 12,000 bees 2. Swarm issues when adult bee population is at least 20,000 bees 6

Bee Colony Activities Throughout The Year

Bee Colony Activities Throughout The Year Written by Khalil Hamdan Apeldoorn The Netherlands A honeybee gathering nectar from a flower. Photo source: forestwander.com Bee collecting pollen. Photo source: