Propolis propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%), and pollen (5%). Propolis also contains persistent lipophilic acaricides, a natural pesticide that deters mite infestations. In neotropical regions, in addition to a large variety of trees, bees may also gather resin from flowers in the genera "Clusia" and "Dalechampia", which are the only known plant genera that produce floral resins to attract pollinators. "Clusia" resin contains polyprenylated benzophenones. In some areas of Chile and Argentina Andean valleys, propolis contains viscidone, a terpene from "Baccharis" shrubs, and in Brazil and Paraguay, naphthoquinone epoxide has
Resorcinol glue Resorcinol glue Resorcinol glue, also known as resorcinol-formaldahyde, is an adhesive combination of resin and hardener that withstands long-term water immersion and has high resistance to ultraviolet light. The adhesive, introduced in 1943, has been popular in aircraft and boat construction. Until the invention of epoxy resin, resorcinol was one of the most common marine glues. Unlike epoxy, it does not have gap filling properties, requiring joints to be close fitting and clamped under pressure to achieve good results. The glue comes in two parts — a red syrup and a light brown powder that were mixed to form glue.