ENT119 - Bee Behavior

domesticated

high difficulty and high mortality without human intervention

feral

domesticated, but returned to the wild

domination

animals change to suit our needs

mutualism

both humans and animals change to accommodate the mutualistic relationship

Bombyx mori

domesticated silkworm in China for at least 5000 years

cannot fly —> cannot live without humans

Bombyx mandarina

wild relative of domesticated silkworm

really different features from the domesticated species

most Apis mellifera are

wild

Why are most Apis mellifera wild?

African or Africanized honeybees —> large geographical space + large proportion of honeybees

not domesticated due to low agricultural means in most of Africa

Buckfast bees

small population of bees that are domesticated

bred in barren land to prevent outcrossing with wild bee populations

commercial uses of artificial selection on bees

honey production

agricultural pollination

artificial selection (traditional breeding)

is not amenable to the biological reproductive tendencies of bees

queens mate with 12 random males in the air —> fancy equipment required to control mating

beekeeping

based on knowledge of bee biology and behavior

method of beekeeping and behavior

find out aggressive triggers and avoid them

find out what triggers more honey production and do it

Langstroth beekeeping uses

removal combs

benefits of Langstroth beekeeping

less destruction to bees

reduced aggression

wax not wasted

bees can be moved between colonies

domestication changes

defensive reaction prevented by preventing the trigger that would normally activate the response

cues

information passively left in the environment by an animal

used by anyone

signals

information intentionally sent by one animal to another

usually within species

_____ evolve from ______

signals evolve from cues

selection works to increase (communication)

production of the cue

sensitivity of the receiver

meaning of a message depends on

context

the receiver and their response

types of communication signals

chemical

mechanical

waggle dance

a recruitment signal by foragers to recruit foragers for food, water, or a new home

forager dances in a figure-8 on the dance floor, waggling her abdomen during the waggle run

waggle dance distance

farther source = longer waggle run

optic flow

how bees determine distance of the source

rate of image flow across retina relative to your position

waggle run direction

vertical angle of waggle dance changes as vertical direction relative to the sun changes

waggle dance quality

determined by rate of energy transfer —> sugar concentration and distance

number of dances correlates with quality of source

waggle dance pheromones

blend of several hydrocarbons

Hymenoptera

mostly parasitoids

Aculeates

all Hymenoptera with ovipositors modified to stingers

most are hunters

bees are most closely related to

ants

evolution of bees

radiated with flowering plants in the Cretaceous period when pollen became abundant

solitary bee life-history

1. adult female emerges or overwinters and mates

2. cell is constructed out of leaves, soil, or wood

3. provision ball made of nectar and pollen built in cell

4. egg laid on provision ball

5. cell is sealed

6. reproductive process restarts

Colletidae

large and diverse group of bees abundant in Australia and S. America

plasterer bees —> line wall of nest with sanitary secretions

all solitary

Halictidae

very common bees

small and metallic in color

sweat bees —> collect sweat from human skin

solitary, parasites, primitively social

Nomia melanderi

commercial halictids used for alfalfa pollination in the PNW

Adrenidae

large group of bees

behavior similar to basic halictids

Mellitidae

small group of bees mostly in Africa

some species collect floral oils instead of pollen

Megachilidae

large group of robust bees

mason/leafcutter bees —> build cells out of leaves, soil and provision each with pollen

inefficient pollen collectors

pollen basket

specialized structure on hindlegs to efficiently collect pollen to bring back to the nest

inefficient pollen collectors are

efficient pollinators

Megachile rotundata

commercial bees used for the pollination of alfalfa

Blue Mason bee

commercial Megachilidae used for tree fruit polllination

moves row to row in orchards v. down rows

Apidae

large and diverse group of bees

Scopae

subfamily of Apidae with hairy legs for pollen transport

typically solitary

includes Allodapine, Carpenter bees

Corbiculate bees

subfamily of Apidae with pollen baskets

includes Orchid bees, stingless bees, bumble bees, honeybees

Carpenter bees

mostly solitary

no hair on abdomens and more oval-shaped thorax

nest in dead wood and line nest with glandular secretions

parental care —> mothers guard nest

nectar robbers

Orchid bees

solitary

males collect odors from flowers and females prefer males with most complex odor

bumble bees

primitively social

commercial pollination in greenhouses through buzz pollination

hair on abdomen and more rounded thorax

weak division of labor within workers where size correlates to task

can communicate food availability but not location

egg incubation

bumble bee life cycle

1. fertilized queen overwinters

2. find a new nest in the spring to start a new colony

3. queen stops foraging when first brood develops

   1. workers produced early in the season and males and new queens produced late in the season

aggregation

cooperative behavior, not just living in high densities

parental care

any help beyond host site selection and laying the eggs

rare in insects

social behavior evolves from

parental care

ethogram

a diagram that depicts various behaviors of social animals (building, foraging, oviposition) and their communications

incipiently eusocial societies

2 different roles based on strength

1. dominant —> reproduction, guarding, building

2. subordinate —> foraging, building

   1. high probability of taking over or mating

2-6 individuals per colony with low physiological differentiation

convergent with cooperative breeding in birds

team-like societies (primitively eusocial)

dozen to hundreds of flexible workers per colony

queen lays eggs and stays in the nest —> physiologically specialized + overtly dominant

division of labor based on simple communication systems

factory-like societies (advanced eusocial)

thousands to millions per colony

permanent worker-queen dimorphism

inflexible physical or temporal castes with elaborate communication systems

eusocial evolution

more division of labor

more complex communication

superorganism

society of highly specialized individuals organized by castes

coordinate by communication with pheromones or acoustic signals

social wasps

paper wasps (Polistes) —> team-like

swarm-founding wasps (Polybia) —> factory-like

social ants

all highly social

Ponerines —> team-like societies of large hunting ants

termites

all highly social

convergence in colony organization with ants —> soldiers and fungus gardening

hemimetabolous insects —> juveniles are workers

bee colonies are organized by

temporal castes, in which bees of different ages specialize on different task sets due to physiological and hormonal changes

honey bee development

castes have distinct physiology and hormonal basis

hormonal reorganization occurs in many places throughout bee’s body

honey bee castes

1. teneral —> low flexibility (1-4 days)

2. nurse —> low flexibility (4-12 days)

3. hive bee —> flexible (12-21 days)

   1. forager —> flexible (21+ days)

hypopharyngeal gland

maximum size during nurse age —> royal jelly proteins

invertase content increases at around middle age

newly emerged bees

clean cells in the brood zone

continue to develop until exoskeleton hardensn

nurses

feed the queen with royal jelly and young with brood food

brood food

protein source for all bees

~ half goes to the workers

middle age bees

process food

build the nest

guard the nestf

foragers

collect nectar, water, pollen, propolis

task repertoires are

discretized with no overlap

workers pass through phases at different pace

workers are

somewhat inflexible

recovery time after demographic disturbance required to restore foraging quantity and quality

stop signal

headbutt and buzzing when in contact with receiver

occurs after harassment at a feeder to stop waggle dancing/allocation of bees to a potentially dangerous feeding site

tremble dance

waggling of abdomen without figure-8 shape to produce substrate vibrations

occurs when there is difficulty unloading nectar after foraging to allocate receivers to the dance floor to receive and process nectar

reduces foraging activity to balance coordination

received by everyone

shaking signal

bee shakes receiver or comb through substrate vibration around the entire hive

occurs at the start and end of foraging —> temporal context

produced by foragers and received by everyone to head towards the dance floor

increase or decrease in foraging activity

primer pheromones

slow developmental changes in the recipients

releaser pheromones

rapid behavioral responses in the recipients

honey bee pheromones

many work together in complex blends

volatile and contact pheromones

used for nest mate recognition, queens, brood, and workers

nest mate recognition pheromones

labels made of complex blend of cuticular hydrocarbons that match a template

queen pheromones

signal reproductive status and activity level

queen mandibular gland pheromone (QMP)

major queen pheromone produced mainly by mandibular glands

used in swarming/queen replacement and caste development

regulates worker bee reproductive developmental hormones

spread by messenger bees

messenger bees

send and spread queen pheromones by licking the queen and walk quickly throughout the nest

footprint pheromone

produced in queen tarsal glands and leaves oily trail where she walks

present of QMP and footprint pheromone

inhibits queen cell production

overcrowded nest —> queen pheromones cannot be spread and indicates need to undergo fission

brood pheromone

complex mixture of fatty acids produced by larva

many meaning depending on receiver —> brood food production, pollen foraging rate

interacts with queen pheromones to control activation of worker ovaries to produce new queens

worker pheromones

signal in many contexts: defense, foraging, division of labor, reproduction biology

ethyl oleate

worker pheromone that regulates division of labor

produced mainly by foragers in the crop to indicate how many active foragers and foraging rate

isopentyl acetate

alarm pheromone released when bee stings to activate fight response in other bees

Nasanov pheromone

worker pheromone used for aggregation in many contexts: foraging, finding home, swarming

blend of 7 compounds made by Nasanov gland

flower signals

worker pheromone that marks flowers when foragers visit a flower

indicates no food left at the flower

can be read between species

bees collect

1. nectar

2. pollen

3. water

4. propolis

quality of sources

quality varies with environment and based on what is available

number of recruits for each site matches

number of dances for each site

variation in number of dances for quality = variation in number of receivers for recruitment

unemployed foragers/recruits

bees use past memories and information on dance floor to find new patches

multiple trips required to find food —> inefficient use of waggle dance information

scouts

consistently monitor environment for new or better sources of food

only foragers present during dirths

collective decision-making

colonies allocate correct number of workers to different sires based on site quality

high quality = high recruitment + low abandonment

pollen collection

unload pollen directly into cells near brood anywhere in the nest

not required when no brood rearing —> homeostatic with negative feedback

assessing pollen content

directly assess pollen need through empty cells and brood pheromones

water collection

metabolic needs and thermoregulation