Sometimes called “bee glue” this material has many properties that the bees use and humans can make use of the material as well.
The order in which these items appear does not indicate any hierarchy of importance.
Vibration reduction… By gluing adjacent parts together the whole structure of the nest is strengthened, but in particular any relative movement between parts that is caused by vibration is greatly reduced and the frequency of any vibration that does still occur is lowered due to the larger lengths and masses of the items that are glued together.
Hole filling is a natural response to the hole itself, but there is a significant advantage to the bees in using propolis to do this… The filled holes become smoother and less able to trap disease spores and bacteria and any such spores or bacteria that are present before the hole filling are effectively encapsulated by the antiseptic material and thus sealed and isolated from the bees. This feature alone would be a strong driving force in natural selection, which would select positively for bees that filled holes.
Propolis is sometimes used as an aromatic barrier by the bees.
Antibiotic, Antiseptic and Antifungal properties are much promoted by the followers of ‘alternative medicine’. I have used Tincture of propolis quite often myself as an agent to promote healing and I have found it useful in restoring sore throats to normal. But in the main I think that the medical properties of propolis are often overstated particularly with regard to aggressive conditions like cancer. There are allergy issues with propolis as well.
Propolis screens (sometimes called propolis grids pictured above) can be used to collect the raw product. The commercially produced grid is rather like a perforated sheet queen excluder, but is made of a polyethylene material three or four millimetres thick. Short round ended slots are of about four millimetres width are punched in the plastic and it is these slots that the bees fill with propolis if the screen is placed on the hive instead of a crown board.
If the screen is removed and frozen then a slight flexing will release lozenge like pellets that are the same shape as the slot. The punching action and the soft nature of the sheet material produce sloping sides to the slots which aid the removal of the pellets.
Netting made from polyethylene yarn can also be used for collection. The adhering propolis being removed by flexure after freezing in a similar manner to the grid.
Humans have used propolis since stone age times when it was used to secure flint arrowheads or spear points.
In more recent times it has been used in violin making, as a component of the varnish on prestigious violins.