Quoted message said:Quoted message said:JE:- I would appreciate information re: nest enclosure of stingless bees. Are their nests less
enclosed than pheromone induced eusocials?
Quoted message said:WH:- Nests of Melipona stingless bees are well enclosed in a fashion similiar to other bees that
reproduce by swarming. One difference might be the hive size which is 1000-2000 workers in
Melapines and can sometimes be much larger in other swarming species. In the closely related
Trigonine bees as in honey bees, female caste fate is nutritionally controlled by workers.
Trigonine bees generally produce no excess queens.
Quoted message said:JE:- Not surprisingly, many ways seem to have evolved to produce eusocial sterility. The common
link seems to be nest enclosure to disperse a regulatory pheromone. Nest size would be limited
by pheromone production and dispersion. Trigonine bees have found another way using pheromone
laced food.
WH:- As to "pheromone laced food", I don't think so. As in most eusocials, workers are using
"nutritional control", the amount of food given a larva, as the direct means of controlling
caste fate.
JE:- Does this mean that these eusocial lava can be maintained permanently sterile by just limiting
nutrition? Is this based on calorific and/or protein limitation or micro nutrient limitation? I
doubt if all eusocials could be maintained permanently sterile by just nutrition so its seems
reasonable to assume that nutrition has been selected to act as a switch?
WH;- Workers are receiving pheromone signals to guide their behavior but the direct cause of
sterility is the amount of food a larva receives not a pheromone in the food. In sub-social bees you
may find direct inducement of sterility via queen pheromones but not in these higher eusocials.
JE:- That appears to be in agreement with what I am supposing: non pheromone control of sterility
evolved from pheromone control.
WH;- Somewhat outside this thread but I will note that one should not look at higher eusocials to
understand how sterility in social insects evolved. One should look at closely related non-social
and sub-social species to best understand how this transition occurred.
JE:- I agree. Non social and sub social forms, as they exist today, could indicate how eusocial
forms may have evolved. If eusociality could have evolved without an enclosed area needed to
disperse a controlling pheromone I predict that eusociality may have become much more common and
may have included humans. However, if selection must firstly evolve a pheromone stage requiring an
enclosed nest then it should be rare, as it appears to be today. Raising some of your own
offspring to become slaves for your own survival is a remarkably good strategy and is allied to
the mass reproduction of forms with little parental care so that most of them die. Clearly, saving
some of these immature forms to act as sterile casts instead of letting them all die is a gain for
the parent.
Naked mole rats seem to be the only mammal eusocial. Maybe in the future they might assimilate the
eusociality sterility phenotype so that no pheromone is required and evolve a non enclosed eusocial
mammal species. Humans use machines as eusocials. Instead of turning all resources into offspring we
manufacture sterile casts called “machines” that do the same job as sterile eusocials. If the net
benefit is a rise in absolute parental fitness, eusocial sterility or machine building, can evolve.
Quoted message said:JE:- From what you say, it appears Melapines can induce eusocial sterility without the need for any
pheromone at all so they do not need an enclosed place to disperse any. Thus their nest size could
be unlimited.
WH:- The key pheromone system for determining hive size is not the pheromone signal to make a worker
or queen but rather the pheromone signal for swarming. This is probably the same in all the swarming
bees (Melapine, Trigorine and honeybee) and this, at least in part, would be the absense or reduced
pheromone of the active egg-laying queen. As hive size/density increases each worker receives less
of this queen pheromone until, at some point, swarming behavior is triggered. After swarming hive
size is reduced by 1/2 and the process repeats.
JE:- The pheromone signal for swarming breaks the hive up so that it determines the size of the
hive? Does this avoid the possibility of two queens within one nest when the nest becomes too large
to distribute the sterility pheromone?
Regards,
John Edser Independent Researcher
PO Box 266 Church Pt NSW 2105 Australia
[email hidden]
