Bee pollen loads and their use in indicating flowering in the Caatinga region of Brazil

The study presents a map of pollen samples collected by Apis mellifera L. in an area of Caatinga (dryland) vegetation in Canudos, Bahia State, Brazil. A total of 62 bee pollen samples obtained from pollen-traps between March/2004 and February/2006 were examined. The pollen loads were acetolyzed and the pollen types identified and counted by sampling using an optical microscope. Thirty-six plant families were found to contribute to the composition of the pollen spectrum of the samples, with 85 different pollen types. Fabaceae was the most represented family (21 pollen types), and Mimosa filipes was the single most frequently observed pollen type (37 samples). The predominant pollen class included 14 pollen types; the secondary class, 18 types; important minor class, 37 types; minor class, 38 types; and 37 “present” pollen types (<1%). Plant species characteristic of the Caatinga region that have apicultural potential, such as Croton spp., Spondias tuberosa Arruda and Ziziphus joazeiro Mart., were well represented in the pollen spectrum. The pollen map was found to be useful for indicating the flowering periods of certain Caatinga species if long and continuous observations were made.