What is the Trigger for Cell Capping? This is not my original idea... the first thoughts on this matter came from John Groocock.
What causes the worker bees to start capping a fully developed grub?
Is this the same trigger that varroa use to initiate migration into the cell?
Can we develop a pheromone to mimic this trigger and use it to make a trap for varroa?
Juvenile hormone is a good candidate, but is this the whole story? I doubt it, I reckon that the volume that the larva represents compared to possible cell volume may well have an influence, both on the bees and on varroa.
Royal jelly quality or at least the constituent percentages of the materials that go to make it up may well vary with the age of the larva being fed, this also calls into question the availability of the 'right mix' of royal jelly from the bees and the distribution within the hive of bees with the correct mix available for the particular age of the larva to be fed.