As long as you keep some open brood in the hive they will never develop laying workers no matter how long they are queenless. Queenlessness is only indirectly responsible for laying workers. It's the worker brood pheromone that suppresses them.
http://www.bushfarms.com/beeslayingworkers.htm#pheromones
See page 11 of Wisdom of the hive:
"the queen's pheromones are neither necessary nor sufficient for inhibiting worker's ovaries. Instead, they strongly inhibit the workers from rearing additional queens. It is now clear that the pheromones that provide the proximate stimulus for workers to refrain from laying eggs come mainly from the brood, not from the queen (reviewed in Seeling 1985; see also Willis, Winston, and Slessor 1990)."
There are always a few laying workers in any hive:
http://www.bushfarms.com/beeslayingworkers.htm#multiple
See page 9 of "The Wisdom of the Hive"
"Although worker honey bees cannot mate, they do possess ovaries and can produce viable eggs; hence they do have the potential to have male offspring (in bees and other Hymenoptera, fertilized eggs produce females while unfertilized eggs produce males). It is now clear, however, that this potential is exceedingly rarely realized as long as a colony contains a queen (in queenless colonies, workers eventually lay large numbers of male eggs; see the review in Page and Erickson 1988). One supporting piece of evidence comes from studies of worker ovary development in queenright colonies, which have consistently revealed extremely low levels of development. All studies to date report far fewer than 1 % of workers have ovaries developed sufficiently to lay eggs (reviewed in Ratnieks 1993; see also Visscher 1995a). For example, Ratnieks dissected 10,634 worker bees from 21 colonies and found that only 7 had moderately developed egg (half the size of a completed egg) and that just one had a fully developed egg in her body."
If you do the math, in a normal booming queenright hive of 100,000 bees that's 70 laying workers. In a laying worker hive it's much higher.
When you get into trouble is when all those thousands of laying workers together start to finally make enough queen pheromones to confuse the bees into thinking that they might have a queen...
http://www.bushfarms.com/beeslayingworkers.htm#pheromones
See page 11 of Wisdom of the hive:
"the queen's pheromones are neither necessary nor sufficient for inhibiting worker's ovaries. Instead, they strongly inhibit the workers from rearing additional queens. It is now clear that the pheromones that provide the proximate stimulus for workers to refrain from laying eggs come mainly from the brood, not from the queen (reviewed in Seeling 1985; see also Willis, Winston, and Slessor 1990)."
There are always a few laying workers in any hive:
http://www.bushfarms.com/beeslayingworkers.htm#multiple
See page 9 of "The Wisdom of the Hive"
"Although worker honey bees cannot mate, they do possess ovaries and can produce viable eggs; hence they do have the potential to have male offspring (in bees and other Hymenoptera, fertilized eggs produce females while unfertilized eggs produce males). It is now clear, however, that this potential is exceedingly rarely realized as long as a colony contains a queen (in queenless colonies, workers eventually lay large numbers of male eggs; see the review in Page and Erickson 1988). One supporting piece of evidence comes from studies of worker ovary development in queenright colonies, which have consistently revealed extremely low levels of development. All studies to date report far fewer than 1 % of workers have ovaries developed sufficiently to lay eggs (reviewed in Ratnieks 1993; see also Visscher 1995a). For example, Ratnieks dissected 10,634 worker bees from 21 colonies and found that only 7 had moderately developed egg (half the size of a completed egg) and that just one had a fully developed egg in her body."
If you do the math, in a normal booming queenright hive of 100,000 bees that's 70 laying workers. In a laying worker hive it's much higher.
When you get into trouble is when all those thousands of laying workers together start to finally make enough queen pheromones to confuse the bees into thinking that they might have a queen...
