Bee behaviour module 6 Flashcards
(233 cards)
1 Define Polyethism
Functional specialization by caste (morphology) or by age in an insect colony leading to division of labour
- List the conditions that
cause variations in polethestic duties
No No Super Ancestry Weather Disturbance
No no super AWD
- Shortage of pollen / stores
- Nosema
- Supercedure/swarming
- Genetic variation
- Cold / wet weather / winter
- Disturbance – eg hive manipulation
Nas 9ODA 9HDA(holds swarm)
Name four pheromones
Nasonov, enables workers to recognise the queen, mark locations and attract drones to queens during mating flights. also used for orientation, particularly at hive entrance
Queen Mandibular pheromone, basis of queen substance 9-oxodec-2-enoic acid (9-ODA) which when distributed throughout colony prevents swarming and workers laying.
9-hydroxydec-2-enoic acid (9-HDA), attracts drones at long distanceand helps hold a swarm together.
Worker Mandibular gland, creates alarm pheromone, used by guard bees to ward off intruders (2-heptanone)
Alarm pheromone from sting gland, (isopentyl acetate) attracts other bees to sting
- List glandular development by age and production
- 3 - hypopharyngeal gland - brood food and royal jelly
- 3 - mandibular gland - brood food
- 12 - wax gland - wax flakes
- 16 - hypopharyngeal gland shrinks - produces invertase and glucose oxidase,
- 12+ mandibular gland - alarm pheromone (2-heptanone)
- 18 - sting gland (Isopentyl acetate)
- Nasonov increases with age; 28 = max;
- List worker duties between emergence in April until death
- 1-3 Cleaning cells, gorging on pollen
- 3-15 feeds larvae and tends queen
- 16-20 receives nectar ripens nectar into honey, packs pollen
- 10-18 makes wax, builds comb,
- ventilates, evaporates, controls temperature (homeostasis)
- 12-25 days guard duty, orientation flights
- 3-6 weeks foraging
- List worker duties between her emergence in OCTOBER until her death
- No income / forage
- Drastically less brood to feed and almost no hive duties
- External temp low, metabolic rate low, so food consumption low
- Focus is on heat conservation in cluster at 20-30C
- Keeping the colony warm, either through creating a denser cluster and/or shivering her dorsoventral muscles to generate metabolic heat
- Around Jan/Feb, as the queen starts laying again, raises temp 33-36C.
- Gradually pick up her duties, limited by the weather & availability of forage
- Orientation - describe the theory behind
‘move a colony less than 3 feet or more than 3 miles’
- Young bees take orientation flights noting local landmarks - bushes
- Successive flights get longer (half a mile)
- By foraging age, it knows local half mile really well
- Foraging bees will follow old routes home automatically
- Move hive -3’ / cut long grass / move landmarks: homecoming bees disorientated for a few hours until they adjust
- Move 3’+ and they return to old site and ‘wait’ for hive to appear
- Move -3 miles, forager may come across old flight paths and revert
- Move 3+ miles, = unlikely to cross old paths so reversion less likely
- Memory lost after about 2 weeks
2 Describe colony mating behaviour 1
- Workers bees do not mate
- Only queens and drones, and they do so on the wing
2 Drone mating - maturation
- Emerges after 24 days
- from colonies with 6000+ bees in April
- 14 days to mature while sperm finishes migrating to seminal vesicles
- Congregate on edges of frames feeding on honey
- Orientation flights followed by flights to DCA during warmest part of day
2 Drone mating
1 attraction
- Attracted to Q by
- Pher: Mandib (9-ODA) - upto 50m away
- Pher: Renner Baumann (tergite) - 30cm
- Sight: sees open bursa copulatrix at 1m
- Comet of D forms with strongest getting to her first
2 Drone mating - 2 act
- Clasps Q from behind with all legs
- Bends abdomen, everts his endophallus into bursa copulatrix with violent contraction
- Q cannot release it.
- Becomes ‘paralysed’, loses hold and swings backwards
- Carried along by the queen as semen is ejaculated into the median and lateral oviducts
- Endophallus ruptures as D falls away, drops to the ground and dies
- The bulb remains in bursa copulatrix - emits UV light - attracts more D
- Mucus from the drone’s mucus glands coagulates and forms a seal “mating sign”
- Next drone removes mating sign
02 mating
How many drones does a queen typically mate with
- 12-15
2 Q mating - 0 maturation
- Emerges after 16 days and eliminates rivals in cells/fights
- 1-4 remains in col feeding herself honey - no RJ and no court
- Exoskeleton hardens; weather permitting takes orientation flights
- Exocrine glands develop esp mandibular: 9-ODA for D attraction
- at 5 days, enough to attract D. Increases over 10 days
- After 5 days she is ready to take mating flights to DCA
- Workers ignore her at first
- When mature, ++ aggresive as she ages without mating (stale prevention)
- After 21 she cannot mate -> drone layer
- If due to inbreeding she produces diploid males, workers eat eggs - mechanism designed to limit drone numbers.
2 Q mating - act
- Mating flights av 30 minutes.
- Between 12-4pm ideally at 20C +.
- Av 2-3km to DCA. At DCA attracts a comet of D.
- Q cannot release D once copulation starts.
- Mated on wing by several D, each removing the mating sign of the last
- Returns to the hive where workers remove last mating sign
- 2-3 mating flights (up to 20D) until her spermatheca is full of sperm.
- Forces the sperm from lateral and median oviducts to her vagina
- Sperm enters spermatheca via spermathecal duct: chemotaxis migration - rest lost but all drones represented
- Workers attend her, feed her royal jelly and form a court
- 3-4 days later: starts laying, maybe haphazardly before settling into gd pattern
- She never leaves the hive again, except to swarm.
- Drone - Describe a DCA 10
Definition: A discrete aerial site where drones fly anticipating the arrival of virgin queens.
- Airspace 15-25m above ground where D congregate and fly around indep of Q(s)
- 100m from apiary
- Open/hilly ground sheltered from wind if poss
- Magnetic attraction? - magnetite in trophocytes in gut
- Mandib gland attracts Drones and Q
- Area 200 x 100m
- Attracts 12 to 10k drones from 5-6km radius (av 1km)
- Minimises inbreeding
- Mating height 10-40m av (can be less) inversely propotional to wind speed
03 Egg laying - 2 rate
What drives the egg laying rate?
- Rate of egg-laying driven by how much Queen is fed
- Thus an artificial flow (feeding mimics a nectar flow) can accelerate egg laying in spring
- Swarm prep - feeding drops off to prepare the queen for flying
- Nectar flow end
- Dearth – eg June gap, August gap
- Winter as nest temperature falls below 33-36C to 20-30C
03 egg laying - 3 brood pattern
Describe a good brood pattern
- Roughly spherical nest to make it easiler to keep warm in cluster
- Densely clustered concentric circles
- Placed in groups at the centre of the frame, but not nec of brood box
- Frames on edges of next tend to have less brood than central frames
- One egg per cell, placed upright and centred at the bottom of a cell
- Drone brood grouped on bottoms/sides of worker brood
- Some empty cells possibly to facilitate warming
- W shape of empty cells over wires
- Uses front legs to assess whether a cell sis W/D. Amputated leg tips -> haphazard laying
3 Egg laying - Describe a typical season’s laying pattern
- Jan/Feb egg laying, but may be earlier if the weather warm
- Spring - queen’s laying rate governed by how much food is available.
- Drone eggs laid in early April in preparation of swarming (May/June)
- More forage (especially pollen) = more eggs
- Up to 1500 per day by late May
- June gap - may slow down. Some strains continue in dearth (Mediterranean)
- Autumn, younger queen may continue laying later into year than older queens, maintaining egg laying after a nectar flow has ended
- Ivy forage Sep-Oct stimulates egg laying, dep on weather and forage
- Late autumn egg laying drops right back
- November/December, likely to be off-lay in colder areas of the UK
3 egg laying - 4
Why is a good brood pattern essential?
- In cold, the cluster can maintain the temperatures in the brood nest
- can’t if brood is spread out all over the place
- More efficient for nurse bees to work areas of brood of the same age
- Workers store pollen in an arc around the brood nest so nurse bees don’t have far to go to reprovision, with honey above the nest area
- Egg laying - why does a queen inspect cells before laying?
- To see if it is clean enough – she is very picky
- To see if it already contains an egg/larva
- To check the width – worker /drone cell
- Season var -
What is the impact of a swarm in Jun on honey harvest
- Depends on strain of bee, forage and weather
- The harvest will be impacted adversely because, effectively, at least a month of foraging has been lost.
- 60% of bees will have ghone with the old queen
- Of those that remain, some will have to come off foraging duties and revert to being nurse bees
- Meanwhile the queen will only start laying, at best, 20 days after emerging.
- Q=8 days to emerge, 4 days to mature, 4 days to mate (assuming perfect weather), 4 days to start laying, 21 days for new bees to start emerging.
- However, it is likely that the bees will be able to store enough to survive the winter as they have the whole of July with the blackberries to feed on.
- Seasonal variation - what is the impact of the month bees swarm
- A swarm in may is worth a load of hay.
- All ok for remaining bees
- but may lack drones to mate new Q so Q may fail next spring from lack of sperm
- A swarm in June is worth a silver spoon
- Temperatures more stable and drones mature.
- Plus plenty fo time for new hive to establish create stores for winter.
- A swarm in July is not worth a fly
- Too late in the year that the swarm lay down enough honey for winter.
- A swarm in August is worth a bale of sawdust
- A swarm in September is a swarm to remember
- Seasonal var

- Title: Av pop cycle over a typical year dep strain, forage, climate, weather
- Lowest adult point end Feb as winter bees die off
- Brood = adults twice that year
- Brood > adults Feb-April - critical period: brood risks being chilled as not enough adults to incubate
- Adults peak in June three weeks after brood peaks (when main flow has started and max foraging force req)
- Pop decreases rapidly as forager bees die off then slows w winter bees
- Pop max 40k-60k dep on fecunidity and strain of Q
- Pop builds in spring with flow (little stored)
- At max pop, they store large amounts for winter in a short time (less brood to care for)
- Reduced pop allows adequate reserves for winter
- Allow for local variations eg peaky graph
- Seasonal var pop 2

- The graph represents the amount of brood in a colony that issues a prime swarm at the end of May.
- x axis is the months of the year Jan to Dec
- Y axis is the amount of brood in 10,000 gradients.
- A Queen started to lay.
- B prime swarm issued.
- D New queen started to lay.
- F queen stopped laying.
- Shaded area. The bees emerging in this area will be winter bees
- Examining the colony at this point one should see:
- No eggs or larvae but some brood.
- Several swarm queen cells on the bottom and side edges of the comb.
- Plenty of workers going about their business foraging and bringing in nectar.
- If the colony is inspected at point C: there may be a virgin queen in the colony and she may be on a mating flight. Opening up the colony may disrupt her return to the colony.
- The risked is reduced by having patience. Wait until you see pollen being taken into the colony, a sure sign that the queen has started to lay.
