Patrick wrote: ↑06 Sep 2019, 12:07
I suppose the rationale is that newly recruited foragers turning up after having been told there was free grub available via dance and trophyllaxis, scout about trying to find out exactly where their sisters found this great bonanza they heard about which they now can't obviously find at the location suggested. If they instead turn up and find an obvious but rapidly diminishing focus for their attention they assume that was it.
As I recall there is no direction given by the dancers for "nectar" sources less than 100ms, so there is lots of frantic random flying to locate what is obviously a really good nectar source nearby.
As I'm pretty isolated and so not worried about anyone else's bees.... I have experimented in the past by providing rich pickings about 20 m's from my hives.
In less than an hour there is absolute frantic tooing and froeing of bees all around my garden searching for the nectar source....this dies down as a veritable cloud of bees have all now discovered the location of the source. And as you correctly point out Patrick, once the source has been consumed the bees leave it alone; although I'm convinced a few scouts still revisit to see if the "flow is back on". Contrary to populist opinion this does not lead to any robbing of other colonies as the books and everyone tells me it should. And as I'm isolated have no issues with diseases as no-one else's bees are close enough.
A second interesting point is If I repeat the experiment a few days later, there is no frantic tooing and froing, they all go immediately to the site. If I want to generate this frantic flying I have to move the source to another part of the garden. Clever bees.
A third interesting point is that a few wasps inevitably turn up, but you can see they have no social recruitment to food sources as their numbers only gradually increase as they follow a scent trail back. And when there is no nectar left the number of wasps noiw outnumbers the numbers the bees Say about 50 wasps in total to an odd visiting bee...stupid wasps.
Robbing, in my experience, is a phenomena of very weak hives/nucs. Bees (and wasps) will exploit a weak hive without any external nectar stimulus, as I have found to my cost in the past.