In colonies of stingless bees, propolis is used for many applications, such as in raw material for constructions and for their defense against enemies. There are records of viscous propolis storage, in form of isolated clusters. In this work, the seasonal characterization of area, number and spatial distribution of isolated propolis clusters in Plebeia emerina (Friese, 1900) colonies is proposed. Colonies were evaluated between October/2003 and September/2004, by measuring in a monthly basis the isolated propolis clusters and recording the relative position of these clusters within the beehives. Between October and March, the area of propolis clusters in the colonies varied between 0.50 and 4.92 cm², and the number of clusters from 3 to 16. In the period from April to September, the area varied between 4.54 and 18.48 cm², and the number of clusters from 9 to 36. It is suggested that the increase of clustered propolis may be related to the preparation of the colonies for the autumn-winter seasons, when there is a reduced collection of the product. The seasonal analysis of the distribution of isolated propolis storages corroborates with the total area records, indicating a preference of the anterior position of the colony for propolis clustering. This fact strengthens the hypothesis that viscous propolis of isolated deposits is used for defense, mainly along the entrance of the colonies.
Stingless bees; defense; Meliponini; propolis; seasonality
