Download Social but not solitary bees reject dangerous flowers where a

SOCIAL BUT NOT SOLITARY BEES
REJECT DANGEROUS FLOWERS
WHERE A CONSPECIFIC HAS
RECENTLY BEEN ATTACKED
Llandres, A.L., Gonzalvez, F.G., & Rodriguez-Girones, M.A.
Social vs. Solitary Bees
Social




Related bees live together
Infertile females
Division of labor
A. mellifera, A. dorsata, A.
florea, B. terrestris
Solitary




Bees are isolated
All females fertile
Builds own nest
N. strigata
Introduction



Animals rely on cues to avoid predators
Avoiding flowers with crushed “conspecifics”
Two types of cues produced by prey
 By-products
of predation
 Alarm signals
2-heptanone
2-methylbutyl
Alarm Signals

2 hypothesized functions:

Signals nectar depletion
(Balderrama, 1996)



Increases efficiency
Marks dangerous flowers
Both social and solitary
bees respond to volatile
cues

Social bees are less wary
Questions

Do bees mark visited flowers to increase efficiency?

Do solitary bees use alarm signals?
 No
studies for the presence of alarm signals in solitary
bees.
Methods


Inflorescence: a cluster of
flowers on one stem
Assigned randomly
 Experimental
 Control


Experimental: bees grasped
over the thorax
Control: bees visit flower and
leave
Methods

Record number of bees after that rejecting or
visiting the flower
 Rejection:
Bee hovers, then leaves.
 Accept: Bee hovers and lands.


All conducted during sunny weather
Tested social bees and solitary bees
Methods

Experiments in six geographical locations
 Baza,
Spain
 Almeria, Spain
 Vulluercas-Ibores, Spain
 Cannonvale, Australia
 MacRitchie Reservoir Park, Singapore
 Xishuangbanna, China


Trials conducted as far away as possible
Experimental: 233, Control: 236
Probability of landing vs. Bee species
***: Social Bees (P<.0001)
NS: Solitary Bees (P>0.25)
Discussion




Social bees release alarm signals to warn of
predators
Treatment had a strong effect on social bees
relative to solitary bees
Solitary bees do not release alarm signals
Limitations: All tests were not run at the same place,
at the same time.
 Different
plant species