Propolis
Propolis or bee glue is a resinous mixture that honey bees produce by mixing saliva and beeswax with exudate gathered from tree buds, sap flows, or other botanical sources. It is used as a sealant for unwanted open spaces in the beehive. Propolis is used for small gaps (around or less), while gaps larger than the bee space (around ) are usually filled with burr comb. Its color varies depending on its botanical source, with dark brown as the most common. Propolis is sticky above , while at lower temperatures, it becomes hard and brittle. When foraging, worker bees primarily harvest pollen and nectar, while also collecting water and plant resin necessary for the production of propolis. The chemical composition and nature of propolis depend on environmental conditions and harvested resources. Types Mixed types of propolis found in European countries with a moderate climate include two or more sources of plant resins (plant species) identified by composition, such as aspen, Mediterranean, poplar, Pacific, Brazilian green, Brazilian red, and Mangifera types of propolis. Purpose Bees seal the beehive with propolis to protect the colony from the elements, such as rain and cold winter drafts. Propolis functions may include: Reinforcing the structural